In-situ loess collapsibility coefficient testing device and method

Abstract

The application discloses a loess collapsibility in-situ testing device and method, which comprises a testing probe inserted into a borehole, an adjusting component arranged at the top of the borehole and used for adjusting the testing probe along the depth direction of the borehole, a water supply device arranged at the top of the borehole and a data acquisition module connected with the testing probe; the method comprises the following steps: 1, two boreholes are formed and the loess collapsibility in-situ testing device is lowered; 2, the loess collapsibility in-situ testing device in one borehole is adjusted; 3, the loading detection of the soil at the bottom of one borehole is carried out; 4, the loading detection of the soil at the bottom of one borehole when the soil is saturated by water is carried out; 5, the loading detection of the soil at the bottom of another borehole when the soil is saturated by water is carried out; and 6, the loess collapsibility in-situ is obtained. The loess collapsibility in-situ testing device and method have the advantages of reasonable design, convenience in implementation, good use effect and capability of measuring the loess collapsibility at any depth.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of geotechnical engineering monitoring, and particularly relates to an in-situ loess collapsibility coefficient testing device and method. BACKGROUND

[0002] Collapsible loess is a special kind of loess, which is widely distributed in the central and western regions of China. This kind of loess has high strength under natural moisture content, but its structure is quickly damaged and its strength is reduced under the action of water immersion under certain pressure, and it also produces significant additional deformation. The rapid development of collapsible deformation and large deformation are harmful to the upper building (structure), which not only hinders the engineering construction in these regions, but also seriously endangers the lives and property safety of the general public. Therefore, the identification of loess collapsibility type and grade is crucial in foundation investigation and design. The commonly used methods for determining loess collapsibility at present include indoor compression test, field static load test and field test pit immersion test. Although the indoor compression test has the advantages of simple operation and clear principle, the completely confined condition is not consistent with the actual situation of foundation deformation and collapsibility. The field static load test and field test pit immersion test can better reflect the actual situation, but they are complex in operation, have large test workload, high water consumption and high cost.

[0003] Therefore, there is a lack of an in-situ loess collapsibility coefficient testing device and method at present, which is simple in testing process, easy to realize and good in use effect, and can measure the collapsibility coefficient of loess at any depth. SUMMARY

[0004] The technical problem to be solved by the present application is to provide an in-situ loess collapsibility coefficient testing device, which is reasonable in design, convenient in operation, simple in testing process, easy to realize, good in use effect and can measure the collapsibility coefficient of loess at any depth, in view of the deficiencies in the prior art.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is: an in-situ loess collapsibility coefficient testing device, characterized in that: it comprises a testing probe inserted into a drill hole, an adjusting component arranged at the top of the drill hole and driving the testing probe to adjust along the depth direction of the drill hole, a water supply device arranged at the top of the drill hole, and a data acquisition module connected with the testing probe.

[0006] The testing probe comprises a protective shell, a first oil cylinder arranged in the lower part of the protective shell, a second oil cylinder arranged in the upper part of the protective shell, a load transmission column connected with the second oil cylinder, and a plurality of force transmission mechanisms in driving connection with the load transmission column, the end part of the force transmission mechanism is provided with an anchor that can tightly adhere to the inner side wall of the drill hole, and the anchor is provided with an anchor plate component; a plurality of force transmission mechanisms are arranged along the height direction of the load transmission column and the depth direction of the drill hole.

[0007] The data acquisition module comprises a first displacement meter arranged at the bottom of the protective shell, a second displacement meter arranged inside the protective shell and used for measuring displacement of the anchoring plate component, and a thimble displacement meter arranged between the lower end of the load transmission column and the top surface of the first oil cylinder, the upper end of the load transmission column being connected with the piston rod of the second oil cylinder, the piston rod of the first oil cylinder being connected with the upper end of the loading rod, the lower end of the loading rod being connected with the load bearing plate;

[0008] The first displacement meter, the second displacement meter and the thimble displacement meter are connected with a data acquisition instrument, and the data acquisition instrument is connected with a data processing terminal.

[0009] The load bearing plate comprises a load bearing base plate and a load bearing cover plate arranged on the top surface of the load bearing base plate, a plurality of mounting holes are arranged in the load bearing base plate, a cylindrical water-permeable stone is arranged in each mounting hole, a through hole is arranged at the center of the load bearing cover plate, a threaded interface is arranged at the center of the load bearing base plate, a threaded joint is arranged at the lower end of the loading rod, the threaded joint is detachably connected with the threaded interface through the through hole, and a lock nut is arranged at the lower end of the loading rod.

[0010] A plurality of upper limiting holes are arranged on the load bearing cover plate, and the center of each upper limiting hole coincides with the center of the cylindrical water-permeable stone.

[0011] The mounting hole comprises an upper large-diameter hole and a small-diameter hole in communication with the upper large-diameter hole, the cylindrical water-permeable stone is arranged in the upper large-diameter hole, the inner diameter of the upper large-diameter hole is adapted to the outer diameter of the cylindrical water-permeable stone, and the outer diameter of the cylindrical water-permeable stone is greater than the inner diameter of the small-diameter hole.

[0012] The upper limiting hole has the same diameter as the inner diameter of the small-diameter hole, and the outer diameter of the cylindrical water-permeable stone is greater than the diameter of the upper limiting hole.

[0013] The first oil cylinder and the second oil cylinder are connected with a hydraulic pump arranged at the top of the drill hole through high-pressure oil pipes.

[0014] The adjusting component comprises a tripod arranged at the top of the drill hole, a winch arranged on the tripod, and a steel cable having one end wound around the winch, and the top plate of the protective shell is provided with a lifting ring, and the other end of the steel cable is tied to the lifting ring.

[0015] The force transmission mechanism comprises a force transmission block sleeved on the load transmission column and a plurality of transmission rod components arranged along the circumferential direction of the force transmission block, and each transmission rod component is provided with an anchor at the end.

[0016] The middle part of the force transmission block is provided with a mounting hole, and a plurality of accommodating grooves are arranged in the circumferential direction of the force transmission block and penetrate the bottom of the force transmission block;

[0017] The transmission rod component comprises an upper connecting rod and a horizontal connecting rod hinged to the upper connecting rod, and the horizontal connecting rod penetrates the protective shell and the sliding bearing embedded on the protective shell;

[0018] The upper end of the upper connecting rod is accommodated in the accommodating groove and is hinged to the force transmission block through a pin shaft, the lower end of the upper connecting rod is hinged to one end of the horizontal connecting rod through a pin shaft, and the anchor is arranged at the other end of the horizontal connecting rod.

[0019] The anchor plate component comprises a sliding rail, an anchor plate attached to the sliding rail, and anchor needles arranged on one side of the anchor plate close to the side of the drill hole, the upper end of the sliding rail is fixedly connected to the inner side of the anchor, a sliding groove is formed in the sliding rail, the sliding groove is arranged along the height direction of the sliding rail, a limiting sliding block is arranged on the other side of the anchor plate and inserted into the sliding groove, and the sliding rail and the limiting sliding block are relatively shifted;

[0020] The pull rope end of the second displacement meter is wound around the reversing wheel through the protective shell and is bound to the limiting sliding block.

[0021] The water supply device comprises a water tank arranged outside the top of the drill hole, a water pump arranged in the water tank, a water pipe connected to the water pump, and an automatic water level controller connected to the water pump to control the switch of the water pump;

[0022] The water pipe is provided with a shower at the bottom of the drill hole, the automatic water level controller is connected to the common probe, the lower limit probe and the upper limit probe through a cable, and the common probe, the lower limit probe and the upper limit probe are arranged in the bottom of the drill hole.

[0023] Meanwhile, the application also discloses a method for testing the in-situ loess collapsibility coefficient, which is simple in method steps and reasonable in design, and the method comprises the following steps:

[0024] Step one, two drill holes are formed and the loess collapsibility in-situ testing device is lowered;

[0025] Step 101, the sundries on the surface of the in-situ loess are cleaned, dry drilling is adopted to form holes on the surface of the in-situ loess to the designed depth, and two drill holes are obtained;

[0026] Step 102, the soil at the bottom of the drill hole is leveled, and medium sand is laid at the bottom of the drill hole;

[0027] Step 103, check the in-situ loess collapsibility coefficient testing device to ensure that each part of the in-situ loess collapsibility coefficient testing device can work normally:

[0028] Step 104, lower the test probe along the borehole by the adjusting component until the bottom of the test probe is 3-5 cm away from the bottom of the borehole, and lower the shower in the water pipe of the water supply device to 15-25 cm from the bottom of the borehole;

[0029] Lower the common probe, lower limit probe and upper limit probe through the cable until the bottom of the common probe and lower limit probe is 5 cm from the bottom of the hole, and the upper limit probe is 15 cm from the bottom of the borehole;

[0030] Step 105, connect the connecting end of the first displacement meter, the thimble displacement meter and the second displacement meter extending out of the top of the borehole to the data acquisition instrument, and connect the first oil cylinder and the second oil cylinder to the hydraulic pump through the high-pressure oil pipe; wherein the data acquisition instrument is connected to the data processing terminal;

[0031] Step two, adjustment of the in-situ loess collapsibility coefficient testing device in one borehole:

[0032] Step 201, the hydraulic pump supplies hydraulic oil to the second oil cylinder through the high-pressure oil pipe to pressurize, so that the piston rod of the second oil cylinder is elongated, and the elongation of the piston rod of the second oil cylinder drives the anchor to tightly adhere to the borehole wall through the force transmission mechanism, and the anchor plate component is anchored to the borehole wall; wherein the test probe and the borehole are coaxially arranged;

[0033] Step 202, elongate the steel cable in the adjusting component, and let the test probe stand in a state free from the tension of the steel cable, the thimble displacement meter detects the third displacement signal and sends it to the acquisition instrument, the acquisition instrument sends the collected third displacement to the data processing terminal, until the third displacement received by the data processing terminal changes by less than 0.10 mm / h in 2 consecutive hours;

[0034] Step 203, the hydraulic pump supplies hydraulic oil to the first oil cylinder through the high-pressure oil pipe to pressurize, so that the piston rod of the first oil cylinder is elongated, and the elongation of the piston rod of the first oil cylinder drives the bearing plate to move downward through the loading rod until the bottom surface of the bearing plate is attached to the bottom of the borehole; wherein the loading pressure exerted by the bearing plate on the bottom of the borehole is zero;

[0035] Step three, loading detection of the soil at the bottom of the borehole in one borehole:

[0036] Step 301, continue to elongate the piston rod of the first oil cylinder to apply a first level loading pressure P1 to the bottom of the borehole by the bottom surface of the bearing plate; wherein the first level loading pressure P1 is in the range of 25-50 kPa;

[0037] Step 302: During the application of the first-stage loading pressure P1, the first displacement signal detected by the first displacement gauge and the second displacement signal detected by the second displacement gauge are sent to the data acquisition instrument. The data acquisition instrument collects the first displacement signal and the second displacement signal in real time and sends them to the data processing terminal. The data processing terminal receives the first displacement value and the second displacement value.

[0038] Step 303: If the difference between the first displacement value and the second displacement value received by the data processing terminal is less than 0.10 mm / h over 2 consecutive hours, then the first-stage loading is stable. Obtain the first displacement value when the first-stage loading is stable and record it as S. 11 The second displacement value when the first stage of loading stabilizes is denoted as S. 12 ;

[0039] Step 304: Apply the k-th stage loading pressure P according to the methods described in steps 301 to 303. k And obtain the first displacement value when the k-th stage of loading stabilizes and denot it as S. k1 The second displacement value when the k-th stage of loading stabilizes is denoted as S. k2 ;

[0040] Step 305: Apply the nth stage loading pressure P as required by the design, following the methods described in steps 301 to 303. n And obtain the first displacement value when the nth level of loading is stable and denot it as S. n1 The second displacement value when the nth stage of loading stabilizes is denoted as S. n2 Where k and n are positive integers, and 1 ≤ k ≤ n;

[0041] Step 4: Loading test when the soil at the bottom of a borehole is saturated with water:

[0042] Step 401: While maintaining the applied nth level loading pressure, inject water into the soil at the bottom of the borehole through the water supply device until the soil is saturated;

[0043] Step 402: Settlement occurs at the bottom of the borehole. Following the methods described in steps 302 and 303, settlement stabilizes when the difference between the first and second displacement values ​​is less than 0.10 mm / h over a continuous 2-hour period. The first displacement value at which settlement stabilizes is then recorded as S′. n1 The second displacement value when the settlement stabilizes is denoted as S′. n2 ;

[0044] Step 5: Loading test when the soil at the bottom of another borehole is saturated with water:

[0045] Step 501: Apply the first-level loading pressure P1 according to the method described in steps 301 to 303 until the first-level loading is stable, and then inject water into the soil at the bottom of another borehole through the water supply device until the soil is saturated.

[0046] Step 502: Maintain the applied first-level loading pressure and follow the methods described in steps 302 to 303 until the difference between the first and second displacement values ​​is less than 0.10 mm / h over a continuous 2 hours. Obtain the first displacement value when the soil stabilizes under the first-level loading and record it as S′. 13 The second displacement value when the soil reaches stability under the first stage of saturated loading is denoted as S′. 14 ;

[0047] Step 503: Following the methods described in steps 501 to 503, apply the k-th level loading pressure P to the saturated soil. k Next, obtain the first displacement value when the soil reaches stability under the k-th level of saturated loading and denote it as S′. k3 The second displacement value when the soil reaches stability under the k-th level of saturated loading is denoted as S′. k4 ;

[0048] Step 504: Following the methods described in steps 501 to 503, apply the nth level loading pressure P to the saturated soil. n Next, obtain the first displacement value when the soil reaches stability under the nth level of saturated loading and denote it as S′. n3 The second displacement value when the soil reaches stability under the k-th level of saturated loading is denoted as S′. n4 ;

[0049] Step Six: Obtaining the in-situ loess collapsibility coefficient:

[0050] Step 601, Judgment Check if the condition is met. If not, proceed to step 602; if met, proceed to step 603.

[0051] Step 602: Follow the methods described in steps one through five until... Established;

[0052] Step 603, according to And according to S″ k3 -S″ k4 =t×(S′) k3 -S′ k4 -(S′ 13 -S′ 14 ))+S′ 13 -S′ 14 The corrected S″ is obtained k3 -S″ k4 ;

[0053] according to The in-situ loess collapsibility coefficient δ was obtained. sk Where D is the diameter of the bearing plate.

[0054] Meanwhile, this invention also discloses another method for testing the in-situ loess collapsibility coefficient that is simple in procedure and reasonably designed, characterized by the following steps: The method includes the following steps:

[0055] Step 1: Formation of multiple boreholes and placement of in-situ testing equipment for loess collapsibility:

[0056] Step 101: Clear debris from the in-situ loess surface and use dry drilling to drill holes to the designed depth in the in-situ loess surface to obtain J holes; wherein the distance between two adjacent holes is 2.0m to 2.5m, and J is a positive integer not less than 3;

[0057] Step 102: Level the soil at the bottom of J boreholes and lay medium sand at the bottom of each of the J boreholes; the thickness of the medium sand is 10mm to 15mm.

[0058] Step 103: Check the in-situ loess collapsibility coefficient testing device to ensure that all parts of the device are functioning properly.

[0059] Step 104: Deploy in-situ loess collapsibility testing devices in all J boreholes; the specific process for deploying the loess collapsibility testing device in any one borehole is as follows:

[0060] First, the test probe is lowered along the borehole using the adjustment component until the bottom of the test probe is 3cm to 5cm from the bottom of the borehole; then, the shower head is lowered to a position 15cm to 25cm from the bottom of the borehole using the water pipe in the water supply device; finally, the common probe, lower limit probe, and upper limit probe are lowered using the cable until the bottom of the common probe and lower limit probe are 5cm from the bottom of the borehole, and the upper limit probe is 15cm from the bottom of the borehole.

[0061] Then, the connecting ends of the first displacement gauge, the pin-type displacement gauge, and the second displacement gauge extending from the top of the borehole are all connected to the data acquisition instrument; and the first and second hydraulic cylinders are both connected to the hydraulic pump through high-pressure oil pipes; wherein, the data acquisition instrument is connected to the data processing terminal;

[0062] Step 2: Adjustment of the in-situ loess collapsibility coefficient testing device in J boreholes:

[0063] The adjustment process for the in-situ loess collapsibility coefficient testing device in all J boreholes is the same. The specific adjustment process for any one borehole's in-situ loess collapsibility coefficient testing device is as follows:

[0064] Step 201: The hydraulic pump supplies hydraulic oil to the second cylinder through a high-pressure oil pipe to pressurize it, so that the piston rod of the second cylinder extends. The extension of the piston rod of the second cylinder drives the anchor to be tightly attached to the borehole wall through the force transmission mechanism. The anchor plate component is anchored to the borehole wall. The test probe and the borehole are coaxially arranged.

[0065] Step 202: The steel cable in the adjustment component is extended. The test probe is placed statically without the tension of the steel cable. The pin-type displacement gauge detects the third displacement signal and sends it to the acquisition instrument. The acquisition instrument sends the acquired third displacement to the data processing terminal until the displacement change of the third displacement received by the data processing terminal within 2 consecutive hours is less than 0.10 mm / h.

[0066] Step 203: The hydraulic pump supplies hydraulic oil to the first cylinder through a high-pressure oil pipe to pressurize it, so that the piston rod of the first cylinder extends. The extension of the piston rod of the first cylinder drives the bearing plate to move downward through the loading rod until the bottom surface of the bearing plate is in contact with the bottom of the drill hole; wherein, the loading pressure applied by the bearing plate to the bottom of the drill hole is zero.

[0067] Step 3: Gradually increase the load on the soil at the bottom of J boreholes using a bearing plate for monitoring.

[0068] Step 301: The piston rod of the first cylinder continues to extend, so that the bottom surface of the bearing plate applies the first loading pressure P′1 to the bottom of the first drill hole; wherein, the value of the first loading pressure P′1 is in the range of 25kPa to 50kPa.

[0069] Step 302: During the application of the first loading pressure P′1, the first displacement signal detected by the first displacement gauge and the second displacement signal detected by the second displacement gauge are sent to the data acquisition instrument. The data acquisition instrument collects the first displacement signal and the second displacement signal in real time and sends them to the data processing terminal. The data processing terminal receives the first displacement value and the second displacement value.

[0070] Step 303: If the difference between the first displacement value and the second displacement value received by the data processing terminal is less than 0.10 mm / h over 2 consecutive hours, then the first loading is stable. Obtain the first displacement value at the time of the first loading stabilization and record it as S. 1,1 The second displacement value when the first loading stabilizes is denoted as S. 1,2 ;

[0071] Step 304: Inject water into the soil at the bottom of the first borehole until the soil is saturated using a water supply device; while maintaining the first loading pressure P′1, the soil at the bottom of the first borehole settles. According to the judgment method described in step 303, the settlement is stable; obtain the first displacement value when the settlement is stable under the first loading pressure P′1 and record it as S′. 1,1 The second displacement value when the settlement stabilizes under the first applied pressure P′1 is denoted as S′. 1,2 ;

[0072] Step 305: Following the methods described in steps 301 to 304, apply load detection to the j-th borehole to obtain the first displacement value when the j-th load stabilizes, and record it as S.j,1 The second displacement value when the j-th stage of loading stabilizes is denoted as S. j,2 ;

[0073] The j-th loading pressure P′ j The first displacement value when the settlement stabilizes is denoted as S′. j,1 The j-th loading pressure P′ j The second displacement value when the settlement stabilizes is denoted as S′. j,2 Where j is a positive integer, and 1≤j≤J;

[0074] Step 306: Apply the Jth loading pressure P′ to the Jth borehole according to the method described in steps 301 to 304. J Load detection; where P′1, ..., P′ j , ..., P′ J Increase sequentially;

[0075] Step 4: Obtaining the in-situ loess collapsibility coefficient:

[0076] According to the formula Obtain the j-th loading pressure P′ j Collapse coefficient δ of lower in-situ loess s,j Where D is the diameter of the bearing plate.

[0077] Compared with the prior art, the present invention has the following advantages:

[0078] 1. The present invention has a simple structure, reasonable design, and is easy to install and deploy.

[0079] 2. The present invention uses a second hydraulic cylinder to drive the test probe to be anchored on the borehole wall, and a first hydraulic cylinder to drive the bearing plate to apply different pressures downward through a loading rod.

[0080] 3. The present invention has an adjustment component that enables the test probe to be adjusted along the borehole depth direction, which not only allows the in-situ loess collapsibility coefficient to be obtained, but also allows the loess collapsibility coefficient to be tested at any depth below 1.5m.

[0081] 4. The present invention is equipped with a load-transfer column and a force-transfer mechanism so that when the test probe reaches the set position of the borehole, the load-transfer column anchors the anchor and anchor plate components to the borehole wall through the force-transfer mechanism. The test probe and the borehole are coaxially arranged, so the test probe is self-stabilized on the borehole wall. There is no need for additional devices such as loads and ground anchors to provide reaction force to the bearing plate. The test equipment is lightweight and easy to operate.

[0082] 5. The present invention is equipped with a first displacement meter, a second displacement meter and a pin-type displacement meter to detect displacement data, which facilitates subsequent testing, judgment and processing to obtain the in-situ loess collapsibility coefficient.

[0083] 6. The in-situ loess collapsibility coefficient testing method of the present invention is simple in steps, easy to implement and operate, and realizes the in-situ loess collapsibility coefficient testing.

[0084] In summary, this invention is reasonably designed, easy to operate, simple to test, convenient to implement, and has good results. It can measure the collapsibility coefficient of loess at any depth.

[0085] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0086] Figure 1 This is a schematic diagram of the in-situ loess collapsibility coefficient testing device of the present invention.

[0087] Figure 2 This is a schematic diagram of the structure of the test probe of the present invention.

[0088] Figure 3 This is a schematic diagram of the structure of the support plate of the present invention.

[0089] Figure 4 This is a schematic diagram of the force transmission mechanism of the present invention.

[0090] Figure 5 This is a schematic diagram of the connecting rod component and anchor of the present invention.

[0091] Figure 6 This is a schematic diagram of the structure of the anchor plate component and the second displacement gauge of the present invention.

[0092] Figure 7 This is a structural schematic diagram of the anchor plate component of the present invention.

[0093] Figure 8 This is a schematic diagram of the water supply device of the present invention.

[0094] Figure 9 This is a flowchart of Embodiment 2 of the present invention.

[0095] Figure 10 This is a flowchart of Embodiment 3 of the present invention.

[0096] Explanation of reference numerals in the attached figures:

[0097] 1—Test probe; 1-1—Carrier plate; 1-1-1—Carrier substrate;

[0098] 1-1-2—Bearing cover plate; 1-1-11—Upper large-diameter hole; 1-1-12—Small-diameter hole;

[0099] 1-1-13—Cylindrical permeable stone; 1-1-14—Threaded interface; 1-1-21—Upper limit hole;

[0100] 1-1-22—Through hole; 1-2—Anti-loosening nut; 1-3—Loading rod;

[0101] 1-4—First displacement gauge; 1-6—Anchor plate component; 1-6-1—Slide rail;

[0102] 1-6-11—Slip groove; 1-6-2—Anchor pin; 1-6-3—Anchor plate;

[0103] 1-6-4—Reversing wheel; 1-6-5—Limit slider; 1-7—Protective housing;

[0104] 1-8—First hydraulic cylinder; 1-9—Pin-type displacement gauge; 1-10—Second displacement gauge;

[0105] 1-11—Anchor; 1-11-1—Arc-shaped rib;

[0106] 1-12—Sliding bearing; 1-13—Load transmission column; 1-14—Second hydraulic cylinder;

[0107] 1-15—Lifting ring; 1-16—Force transmission mechanism; 1-16-1—Force transmission block;

[0108] 1-16-11—Mounting hole; 1-16-12—Receiving groove;

[0109] 1-16-2—Pin; 1-16-3—Upper connecting rod; 1-16-4—Horizontal connecting rod;

[0110] 2-1—Common probe; 2-2—Lower limit probe; 2-3—Upper limit probe;

[0111] 3—Shower head; 4—Water pipe; 5—Water supply device;

[0112] 5-1—Water tank; 5-2—Automatic water level controller; 5-3—Water pump;

[0113] 6—Tripod; 7—Windlock; 8—Steel cable;

[0114] 9—High-pressure oil pipe; 10—Hydraulic pump; 11—Data acquisition instrument;

[0115] 12—Data processing terminal; 13—Cable; 14—Drill hole. Detailed Implementation

[0116] Example 1

[0117] like Figures 1 to 2The in-situ loess collapsibility coefficient testing device shown includes a test probe 1 that extends into a borehole 14, an adjustment component that is set at the top of the borehole 14 and drives the test probe 1 to adjust along the depth direction of the borehole 14, a water supply device 5 set at the top of the borehole 14, and a data acquisition module connected to the test probe 1.

[0118] The test probe 1 includes a protective shell 1-7, a first hydraulic cylinder 1-8 disposed in the lower part of the protective shell 1-7, a second hydraulic cylinder 1-14 disposed in the upper part of the protective shell 1-7, a load-transfer column 1-13 connected to the second hydraulic cylinder 1-14, and a plurality of force-transfer mechanisms 1-16 connected to the load-transfer column 1-13. The end of the force-transfer mechanism 1-16 is provided with an anchor 1-11 that can be tightly attached to the inner wall of the borehole 14. An anchor plate component 1-6 is provided on the anchor 1-11. The plurality of force-transfer mechanisms are arranged along the height of the load-transfer column 1-13 and the depth of the borehole 14.

[0119] The data acquisition module includes a first displacement meter 1-4 disposed at the bottom of the protective shell 1-7, a second displacement meter 1-10 disposed inside the protective shell 1-7 for measuring the displacement of the anchor plate component 1-6, and a pin-type displacement meter 1-9 disposed between the lower end of the load transfer column 1-13 and the top surface of the first hydraulic cylinder 1-8. The upper end of the load transfer column 1-13 is connected to the piston rod of the second hydraulic cylinder 1-14, the piston rod of the first hydraulic cylinder 1-8 is connected to the upper end of the loading rod 1-3, and the lower end of the loading rod 1-3 is connected to the bearing plate 1-1.

[0120] The first displacement gauge 1-4, the second displacement gauge 1-10, and the pin-type displacement gauge 1-9 are all connected to the data acquisition instrument 11, which is connected to the data processing terminal 12.

[0121] like Figure 3 As shown, in this embodiment, the support plate 1-1 includes a support substrate 1-1-1 and a support cover plate 1-1-2 disposed on the top surface of the support substrate 1-1-1. The support substrate 1-1-1 is provided with a plurality of mounting holes, and a cylindrical permeable stone 1-1-13 is placed in the mounting holes. The support cover plate 1-1-2 is provided with a through hole 1-1-22 at its center position. The support substrate 1-1-1 is provided with a threaded interface 1-1-14 at its center position. The lower end of the loading rod 1-3 is provided with a threaded connector. The threaded connector passes through the through hole 1-1-22 and is detachably connected to the threaded interface 1-1-14. The lower end of the loading rod 1-3 is fitted with an anti-loosening nut 1-2.

[0122] The bearing cover plate 1-1-2 is provided with a plurality of upper limit holes 1-1-21, the center of the upper limit holes 1-1-21 coincides with the center of the cylindrical permeable stone 1-1-13.

[0123] like Figure 3 As shown, in this embodiment, the mounting hole includes a large-diameter hole 1-1-11 and a small-diameter hole 1-1-12 communicating with the large-diameter hole 1-1-11. The cylindrical permeable stone 1-1-13 is located in the large-diameter hole 1-1-11. The inner diameter of the large-diameter hole 1-1-11 and the outer diameter of the cylindrical permeable stone 1-1-13 are adapted to each other. The outer diameter of the cylindrical permeable stone 1-1-13 is larger than the inner diameter of the small-diameter hole 1-1-12.

[0124] The upper limit hole 1-1-21 has the same diameter as the inner diameter of the small diameter hole 1-1-12, and the outer diameter of the cylindrical permeable stone 1-1-13 is larger than the diameter of the upper limit hole 1-1-21.

[0125] In this embodiment, the first oil cylinder 1-8 and the second oil cylinder 1-14 are both connected to the hydraulic pump 10 located at the top of the borehole 14 via high-pressure oil pipe 9.

[0126] The adjustment component includes a tripod 6 set on the top of the borehole 14, a winch 7 set on the tripod 6, and a steel cable 8 with one end wound on the winch 7. The top plate of the protective shell 1-7 is provided with a lifting ring 1-15, and the other end of the steel cable 8 is tied to the lifting ring 1-15.

[0127] like Figure 4 and Figure 5 As shown, in this embodiment, the force transmission mechanism 1-16 includes a force transmission block 1-16-1 sleeved on the load transmission column 1-13 and a plurality of transmission rod components arranged along the circumferential direction of the force transmission block 1-16-1, and each transmission rod component is provided with an anchor 1-11 at its end.

[0128] The force transmission block 1-16-1 has a mounting hole 1-16-11 in the middle and a plurality of receiving grooves 1-16-12 in the circumferential direction. The receiving grooves 1-16-12 penetrate the bottom of the force transmission block 1-16-1.

[0129] The transmission rod component includes an upper connecting rod 1-16-3 and a horizontal connecting rod 1-16-4 hinged to the upper connecting rod 1-16-3. The horizontal connecting rod 1-16-4 passes through the protective shell 1-7 and the sliding bearing 1-12 embedded in the protective shell 1-7.

[0130] The upper end of the upper connecting rod 1-16-3 is accommodated in the receiving groove 1-16-12 and is hinged to the force transmission block 1-16-1 via a pin 1-16-2. The lower end of the upper connecting rod 1-16-3 is hinged to one end of the horizontal connecting rod 1-16-4 via a pin 1-16-2. The anchor 1-11 is located at the other end of the horizontal connecting rod 1-16-4.

[0131] like Figure 6 and Figure 7 As shown, in this embodiment, the anchor plate component 1-6 includes a slide rail 1-6-1, an anchor plate 1-6-3 attached to the slide rail 1-6-1, and anchor pins 1-6-2 disposed on one side of the plurality of anchor plates 1-6-3 near the drill hole 14. The upper end of the slide rail 1-6-1 is fixedly connected to the inner side of the anchor 1-11. A groove 1-6-11 is provided on the slide rail 1-6-1. The groove 1-6-11 is arranged along the height direction of the slide rail 1-6-1. A limiting slider 1-6-5 is provided on the other side of the anchor plate 1-6-3 and inserted into the groove 1-6-11. The slide rail 1-6-1 and the limiting slider 1-6-5 slide relative to each other.

[0132] The pull rope end of the second displacement gauge 1-10 passes through the protective shell 1-7, goes around the reversing wheel 1-6-4, and is then tied to the limit slider 1-6-5.

[0133] like Figure 8 As shown, in this embodiment, the water supply device 5 includes a water tank 5-1 disposed outside the top of the borehole 14, a water pump 5-3 disposed in the water tank 5-1, a water pipe 4 connected to the water pump 5-3, and an automatic water level controller 5-2 connected to the water pump 5-3 to control the switch of the water pump 5-3.

[0134] The water pipe 4 extends into the bottom of the borehole 14 and is equipped with a shower head 3. The automatic water level controller 5-2 is connected to the common probe 2-1, the lower limit probe 2-2, and the upper limit probe 2-3 via a cable 13. The common probe 2-1, the lower limit probe 2-2, and the upper limit probe 2-3 are located inside the bottom of the borehole 14.

[0135] In this embodiment, the other side of the anchor plate 1-6-3 is attached to the slide rail 1-6-1, and a limiting slider 1-6-5 is set to limit the slide rail 1-6-1 as it slides up and down with the test probe 1. The limiting slider 1-6-5 remains stationary with the position of the anchor plate 1-6-3, thereby realizing the displacement detection of the second displacement meter 1-10.

[0136] In this embodiment, the lower limit liquid level is detected by using the common probe 2-1 and the lower limit probe 2-2; the upper limit liquid level is detected by using the common probe 2-1 and the upper limit probe 2-3.

[0137] In this embodiment, the pin end of the pin-type displacement gauge 1-9 is in contact with the bottom surface of the load transfer column 1-13, and the bottom of the pin-type displacement gauge 1-9 is connected to the top surface of the first oil cylinder 1-8.

[0138] In this embodiment, the outer diameter of the cylindrical permeable stone 1-1-13 is larger than the inner diameter of the small diameter hole 1-1-12 to prevent the cylindrical permeable stone 1-1-13 from falling off.

[0139] In this embodiment, the outer diameter of the cylindrical permeable stone 1-1-13 is larger than the diameter of the upper limit hole 1-1-21, thereby limiting the upper part of the cylindrical permeable stone 1-1-13 and preventing the cylindrical permeable stone 1-1-13 from being pushed out.

[0140] In this embodiment, both the supporting substrate 1-1-1 and the supporting cover plate 1-1-2 are cylindrical.

[0141] In this embodiment, the radius of the drill hole 14 is 10cm larger than the radius of the support plate 1-1, and the radius of the drill hole 14 is 50cm to 60cm.

[0142] In this embodiment, the inner diameter of the upper large-diameter hole 1-1-11 is 1cm, the diameter of the upper limit hole 1-1-21 and the inner diameter of the small-diameter hole 1-1-12 are 0.8cm, and the thickness of the cylindrical permeable stone 1-1-13 is 5cm.

[0143] In this embodiment, the bearing plate 1-1 is connected to the loading rod 1-3 by the connecting thread 1-1-14, and the connection between the loading rod 1-3 and the bearing plate 1-1 is reinforced by the anti-loosening nut 1-2.

[0144] In this embodiment, the hydraulic gauge built into the hydraulic pump 10 can display the hydraulic oil pressure.

[0145] In this embodiment, during actual use, the receiving groove 1-16-12 does not penetrate the top surface of the force transmission block 1-16-1 and the inner sidewall of the force transmission block 1-16-1, ensuring that the force transmission block 1-16-1 and the load transmission column 1-13 are connected.

[0146] In this embodiment, during actual use, the lower end of the upper connecting rod 1-16-3 is provided with an ear seat, and one end of the horizontal connecting rod 1-16-4 is provided with an ear plate. The ear plate extends into the ear seat and is hinged by the pin 1-16-2.

[0147] In this embodiment, the anchor 1-11 is an arc-shaped anchor, and the outer side of the anchor 1-11 is provided with evenly distributed arc-shaped ribs 1-11-1, while the inner side is smooth. The arc-shaped ribs 1-11-1 increase friction so that the anchor 1-11 is securely installed against the inner wall of the borehole 14.

[0148] In this embodiment, there are three transmission rod components and three anchors 1-11. The three anchors 1-11 are distributed in pairs at 120 degrees to each other in the plane. Each anchor 1-11 has a hole at the center of its plate. The bolt passes through the hole and extends into the other end of the horizontal connecting rod 1-16-4, and the end of the bolt is embedded in the anchor 1-11.

[0149] One end of the horizontal connecting rod 1-16-4 is connected to the upper connecting rod 1-16-3 via a pin 1-16-2. The horizontal connecting rod 1-16-4 passes through the sliding bearing 1-12, ensuring the direction of movement of the horizontal connecting rod 1-16-4. The pin 1-16-2 ensures that the upper connecting rod 1-16-3 rotates around the pin 1-16-2. The upper connecting rod 1-16-3 is connected to the force transmission block 1-16-1 via the pin 1-16-2. The force transmission block 1-16-1 is circular.

[0150] When the second cylinder 1-14 applies a telescopic force, it can drive the load transmission column 1-13 to move downward, and simultaneously drive the force transmission block 1-16-1 to move downward. Under the action of the upper connecting rod 1-16-3, the horizontal connecting rod 1-16-4 can move along the horizontal direction, thereby driving the anchor 1-11 to be tightly and firmly attached to the wall of the borehole 14.

[0151] In this embodiment, the first displacement gauge 1-4 is a pull-rope type displacement gauge, which is installed on the outer bottom surface of the protective shell 1-7 of the test probe 1. The pull-rope end is installed on the bearing cover plate 1-1-2 of the bearing plate 1-1, and can measure the relative displacement of the bearing plate 1-1.

[0152] In this embodiment, the upper end of the slide rail 1-6-1 is installed on the inner side of the anchor 1-11, and can move along the horizontal direction with the anchor 1-11.

[0153] The second displacement gauge 1-10 is a pull-rope type displacement gauge. When testing, under the action of the pull rope of the second displacement gauge 1-10, the anchor plate 1-6-3 is at the upper end of the slide rail 1-6-1. The second hydraulic cylinder 1-14 causes the anchor 1-11 to move. At this time, the slide rail 1-6-1 can drive the anchor pin 1-6-2 on the anchor plate 1-6-3 to penetrate into the hole wall of the drill hole 14. When the slide rail 1-6-1 moves upward with the test probe 1 as a whole, the anchor plate 1-6-3 is stationary relative to the hole wall of the drill hole 14. At this time, the pull rope of the second displacement gauge 1-10 extends or retracts, and the relative displacement of the probe 1 can be tested.

[0154] In this embodiment, the common probe 2-1, lower limit probe 2-2, and upper limit probe 2-3 are set up to detect the water level at the bottom of borehole 14 when the soil at the bottom of borehole 14 is soaked with water. When the water level is lower than the lower limit probe 2-2, the automatic water level controller 5-2 turns on the power of the water pump 5-3. The water pump 5-3 pumps water and delivers it to the shower head 3 through the water pipe 4 to inject water into the bottom of borehole 14. When the water level at the bottom of borehole 14 reaches the height of the upper limit probe 2-3, the automatic water level controller 5-2 automatically disconnects the power of the water pump 5-3, and the water pump 5-3 stops working, thus stopping the injection of water into the bottom of borehole 14. This device can keep the soil at the bottom of borehole 14 saturated.

[0155] Example 2

[0156] like Figure 8 The method for testing the in-situ loess collapsibility coefficient, as shown, includes the following steps:

[0157] Step 1: Formation of two boreholes and placement of the in-situ testing device for loess collapsibility:

[0158] Step 101: Clear debris from the surface of the loess in situ, and use dry drilling to drill holes to the designed depth on the surface of the loess in situ, obtaining two boreholes 14;

[0159] Step 102: Level the soil at the bottom of borehole 14 and lay medium sand at the bottom of borehole 14;

[0160] Step 103: Check the in-situ loess collapsibility coefficient testing device to ensure that all parts of the device are functioning properly.

[0161] Step 104: Lower the test probe 1 along the drill hole 14 using the adjustment component until the bottom of the test probe 1 is 3cm to 5cm from the bottom of the drill hole 14; and lower the shower head 3 to a position 15cm to 25cm from the bottom of the drill hole 14 using the water pipe 4 in the water supply device 5.

[0162] Lower the common probe 2-1, lower limit probe 2-2, and upper limit probe 2-3 through cable 13 until the bottom of the common probe 2-1 and the lower limit probe 2-2 are 5cm away from the bottom of the hole, and the upper limit probe 2-3 is 15cm away from the bottom of the borehole 14.

[0163] Step 105: Connect the connecting ends of the first displacement gauge 1-4, the pin-type displacement gauge 1-9, and the second displacement gauge 1-10 extending from the top of the borehole 14 to the data acquisition instrument 11; and connect the first hydraulic cylinder 1-8 and the second hydraulic cylinder 1-14 to the hydraulic pump 10 through the high-pressure oil pipe 9; wherein, the data acquisition instrument 11 is connected to the data processing terminal 12.

[0164] Step 2: Adjustment of the in-situ loess collapsibility coefficient testing device in a borehole:

[0165] Step 201: The hydraulic pump 10 supplies hydraulic oil to the second cylinder 1-14 through the high-pressure oil pipe 9 to pressurize it, so that the piston rod of the second cylinder 1-14 extends. The extension of the piston rod of the second cylinder 1-14 drives the anchor 1-11 to be tightly attached to the borehole wall of the drill hole 14 through the force transmission mechanism 1-16. The anchor plate component 1-6 is anchored to the borehole wall of the drill hole 14. The test probe 1 and the drill hole 14 are coaxially arranged.

[0166] Step 202: The steel cable 13 in the adjustment component is extended. The test probe 1 is placed statically without the tension of the steel cable 13. The pin-type displacement gauge 1-9 detects the third displacement signal and sends it to the acquisition instrument 11. The acquisition instrument 11 sends the acquired third displacement to the data processing terminal 12 until the displacement change of the third displacement received by the data processing terminal 12 within 2 consecutive hours is less than 0.10 mm / h.

[0167] Step 203: The hydraulic pump 10 supplies hydraulic oil to the first cylinder 1-8 through the high-pressure oil pipe 9 to pressurize it, so that the piston rod of the first cylinder 1-8 extends. The extension of the piston rod of the first cylinder 1-8 drives the bearing plate 1-1 to move downward through the loading rod 1-3 until the bottom surface of the bearing plate 1-1 is in contact with the bottom of the drill hole 14; wherein, the loading pressure applied by the bearing plate 1-1 to the bottom of the drill hole 14 is zero.

[0168] Step 3: Loading test of the soil at the bottom of a borehole:

[0169] Step 301: The piston rod of the first cylinder 1-8 continues to extend, so that the bottom surface of the bearing plate 1-1 applies a first-stage loading pressure P1 to the bottom of the drill hole 14; wherein, the value of the first-stage loading pressure P1 is in the range of 25kPa to 50kPa.

[0170] Step 302: During the application of the first-stage loading pressure P1, the first displacement signal detected by the first displacement gauge 1-4 and the second displacement signal detected by the second displacement gauge 1-10 are sent to the data acquisition instrument 11. The data acquisition instrument 11 collects the first displacement signal and the second displacement signal in real time and sends them to the data processing terminal 12. The data processing terminal 12 receives the first displacement value and the second displacement value.

[0171] Step 303: If the difference between the first displacement value and the second displacement value received by the data processing terminal 12 is less than 0.10 mm / h over a continuous 2 hours, then the first-stage loading is stable. The first displacement value at which the first-stage loading is stable is obtained and recorded as S. 11 The second displacement value when the first stage of loading stabilizes is denoted as S. 12 ;

[0172] Step 304: Apply the k-th stage loading pressure P according to the methods described in steps 301 to 303. k And obtain the first displacement value when the k-th stage of loading stabilizes and denot it as S. k1 The second displacement value when the k-th stage of loading stabilizes is denoted as S. k2 ;

[0173] Step 305: Apply the nth stage loading pressure P as required by the design, following the methods described in steps 301 to 303. n And obtain the first displacement value when the nth level of loading is stable and denot it as S.n1 The second displacement value when the nth stage of loading stabilizes is denoted as S. n2 Where k and n are positive integers, and 1 ≤ k ≤ n;

[0174] Step 4: Loading test when the soil at the bottom of a borehole is saturated with water:

[0175] Step 401: While maintaining the applied nth level loading pressure, inject water into the soil at the bottom of borehole 14 through water supply device 5 until the soil is saturated;

[0176] Step 402: Settlement occurs at the bottom of borehole 14. Following the methods described in steps 302 and 303, settlement is considered stable when the difference between the first and second displacement values ​​is less than 0.10 mm / h over a continuous 2-hour period. The first displacement value at which settlement stabilizes is then recorded as S′. n1 The second displacement value when the settlement stabilizes is denoted as S′. n2 ;

[0177] Step 5: Loading test when the soil at the bottom of another borehole is saturated with water:

[0178] Step 501: Apply the first-level loading pressure P1 according to the method described in steps 301 to 303 until the first-level loading is stable, and then inject water into the soil at the bottom of another borehole 14 through the water supply device 5 until the soil is saturated.

[0179] Step 502: Maintain the applied first-level loading pressure and follow the methods described in steps 302 to 303 until the difference between the first and second displacement values ​​is less than 0.10 mm / h over a continuous 2 hours. Obtain the first displacement value when the soil stabilizes under the first-level loading and record it as S′. 13 The second displacement value when the soil reaches stability under the first stage of saturated loading is denoted as S′. 14 ;

[0180] Step 503: Following the methods described in steps 501 to 503, apply the k-th level loading pressure P to the saturated soil. k Next, obtain the first displacement value when the soil reaches stability under the k-th level of saturated loading and denote it as S′. k3 The second displacement value when the soil reaches stability under the k-th level of saturated loading is denoted as S′. k4 ;

[0181] Step 504: Following the methods described in steps 501 to 503, apply the nth level loading pressure P to the saturated soil. n Next, obtain the first displacement value when the soil reaches stability under the nth level of saturated loading and denote it as S′. n3 The second displacement value when the soil reaches stability under the k-th level of saturated loading is denoted as S′. n4 ;

[0182] Step Six: Obtaining the in-situ loess collapsibility coefficient:

[0183] Step 601, Judgment Check if the condition is met. If not, proceed to step 602; if met, proceed to step 603.

[0184] Step 602: Follow the methods described in steps one through five until... Established;

[0185] Step 603, according to And according to S″ k3 -S″ k4 =t×(S′) k3 -S′ k4 -(S′ 13 -S′ 14 ))+S′ 13 -S′ 14 The corrected S″ is obtained k3 -S″ k4 ;

[0186] according to The in-situ loess collapsibility coefficient δ was obtained. sk Where D is the diameter of the bearing plate 1-1.

[0187] In this embodiment, the distance between two adjacent boreholes 14 is 2.0m to 2.5m; the thickness of the medium sand is 10mm to 15mm. The medium sand layer is set to ensure that the load on the soil at the bottom of the borehole is uniform.

[0188] In this embodiment, the test probe 1 is lowered along the drill hole 14 using the adjustment component, and the specific process is as follows:

[0189] The test probe 1 is lowered along the borehole 14 by the winch 7 via the steel cable 8.

[0190] In this embodiment, in step 201, the piston rod of the second hydraulic cylinder 1-14 extends and is tightly attached to the borehole wall of the drilled hole 14 through the force transmission mechanism 1-16, and the anchor plate component 1-6 is anchored to the borehole wall of the drilled hole 14. The specific process is as follows:

[0191] The piston rod of the second cylinder 1-14 extends, causing the load transmission column 1-13 to move downward, which in turn causes the force transmission block 1-16-1 to move downward. Under the action of the upper connecting rod 1-16-3, the horizontal connecting rod 1-16-4 moves along the horizontal direction, thereby causing the anchor 1-11 to be tightly attached to the borehole wall of the drill hole 14, and the anchor plate component 1-6 to be anchored to the borehole wall of the drill hole 14.

[0192] In this embodiment, water is injected into the soil at the bottom of borehole 14 through water supply device 5 until the soil is saturated. The specific process is as follows:

[0193] When the water level at the bottom of borehole 14 is lower than the lower limit probe 2-2, the automatic water level controller 5-2 connects the power supply to the water pump 5-3. The water pump 5-3 pumps water and delivers it through the water pipe 4 to the shower head 3 to inject water into the bottom of borehole 14. When the water level at the bottom of borehole 14 reaches the height of the upper limit probe 2-3, the automatic water level controller 5-2 automatically disconnects the power supply to the water pump 5-3. The water pump 5-3 stops working, and the injection of water into the bottom of borehole 14 stops until the water level at the bottom of borehole 14 reaches the height of the upper limit probe 2-3 and does not change, so that the soil at the bottom of borehole 14 is saturated with water.

[0194] In this embodiment, when k is greater than or equal to 2, the k-th stage loading pressure P k When P does not exceed 150 kPa, k -P k-1 The value range is 25 kPa to 50 kPa; the k-th stage loading pressure P k When P exceeds 150 kPa, k -P k-1 The value range is 50 kPa to 100 kPa.

[0195] In this embodiment, medium sand refers to sand and gravel with a particle size of 0.25mm to 0.5mm.

[0196] Example 3

[0197] like Figure 9 The method for testing the in-situ loess collapsibility coefficient, as shown, includes the following steps:

[0198] Step 1: Formation of multiple boreholes and placement of in-situ testing equipment for loess collapsibility:

[0199] Step 101: Clear debris from the in-situ loess surface and use dry drilling to drill holes to the designed depth in the in-situ loess surface to obtain J holes 14; wherein the distance between two adjacent holes 14 is 2.0m to 2.5m, and J is a positive integer not less than 3;

[0200] Step 102: Level the soil at the bottom of J boreholes 14, and lay medium sand at the bottom of each of the J boreholes 14; the thickness of the medium sand is 10mm to 15mm.

[0201] Step 103: Check the in-situ loess collapsibility coefficient testing device to ensure that all parts of the device are functioning properly.

[0202] Step 104: Deploy in-situ loess collapsibility testing devices in all J boreholes 14; the specific process for deploying the loess collapsibility testing device in any one of the boreholes 14 is as follows:

[0203] First, the test probe 1 is lowered along the borehole 14 using the adjustment component until the bottom of the test probe 1 is 3cm to 5cm from the bottom of the borehole 14; then, the shower head 3 is lowered to a position 15cm to 25cm from the bottom of the borehole 14 using the water pipe 4 in the water supply device 5; finally, the common probe 2-1, the lower limit probe 2-2, and the upper limit probe 2-3 are lowered using the cable 13 until the bottoms of the common probe 2-1 and the lower limit probe 2-2 are 5cm from the bottom of the borehole, and the upper limit probe 2-3 is 15cm from the bottom of the borehole 14.

[0204] Then, the connecting ends of the first displacement gauge 1-4, the pin-type displacement gauge 1-9, and the second displacement gauge 1-10 extending from the top of the borehole 14 are all connected to the data acquisition instrument 11; and the first hydraulic cylinder 1-8 and the second hydraulic cylinder 1-14 are both connected to the hydraulic pump 10 through the high-pressure oil pipe 9; wherein, the data acquisition instrument 11 is connected to the data processing terminal 12.

[0205] Step 2: Adjustment of the in-situ loess collapsibility coefficient testing device in J boreholes:

[0206] The adjustment process for the in-situ loess collapsibility coefficient testing device in all J boreholes is the same. The specific adjustment process for any one borehole's in-situ loess collapsibility coefficient testing device is as follows:

[0207] Step 201: The hydraulic pump 10 supplies hydraulic oil to the second cylinder 1-14 through the high-pressure oil pipe 9 to pressurize it, so that the piston rod of the second cylinder 1-14 extends. The extension of the piston rod of the second cylinder 1-14 drives the anchor 1-11 to be tightly attached to the borehole wall of the drill hole 14 through the force transmission mechanism 1-16. The anchor plate component 1-6 is anchored to the borehole wall of the drill hole 14. The test probe 1 and the drill hole 14 are coaxially arranged.

[0208] Step 202: The steel cable 13 in the adjustment component is extended. The test probe 1 is placed statically without the tension of the steel cable 13. The pin-type displacement gauge 1-9 detects the third displacement signal and sends it to the acquisition instrument 11. The acquisition instrument 11 sends the acquired third displacement to the data processing terminal 12 until the displacement change of the third displacement received by the data processing terminal 12 within 2 consecutive hours is less than 0.10 mm / h.

[0209] Step 203: The hydraulic pump 10 supplies hydraulic oil to the first cylinder 1-8 through the high-pressure oil pipe 9 to pressurize it, so that the piston rod of the first cylinder 1-8 extends. The extension of the piston rod of the first cylinder 1-8 drives the bearing plate 1-1 to move downward through the loading rod 1-3 until the bottom surface of the bearing plate 1-1 is in contact with the bottom of the drill hole 14; wherein, the loading pressure applied by the bearing plate 1-1 to the bottom of the drill hole 14 is zero.

[0210] Step 3: Gradually increase the load on the soil at the bottom of J boreholes using a bearing plate for monitoring.

[0211] Step 301: The piston rod of the first cylinder 1-8 continues to extend, so that the bottom surface of the bearing plate 1-1 applies the first loading pressure P′1 to the bottom of the first drill hole 14; wherein the value of the first loading pressure P1′ is in the range of 25kPa to 50kPa.

[0212] Step 302: During the application of the first loading pressure P′1, the first displacement signal detected by the first displacement gauge 1-4 and the second displacement signal detected by the second displacement gauge 1-10 are sent to the data acquisition instrument 11. The data acquisition instrument 11 collects the first displacement signal and the second displacement signal in real time and sends them to the data processing terminal 12. The data processing terminal 12 receives the first displacement value and the second displacement value.

[0213] Step 303: If the difference between the first displacement value and the second displacement value received by the data processing terminal 12 is less than 0.10 mm / h over 2 consecutive hours, then the first loading is stable. The first displacement value at the time of the first loading stabilization is obtained and recorded as S. 1,1 The second displacement value when the first loading stabilizes is denoted as S. 1,2 ;

[0214] Step 304: Inject water into the soil at the bottom of the first borehole 14 through the water supply device 5 until the soil is saturated; while maintaining the first loading pressure P1′, the soil at the bottom of the first borehole 14 settles. According to the judgment method described in step 303, the settlement is stable; obtain the first displacement value when the settlement is stable under the first loading pressure P1′ and record it as S′. 1,1 The second displacement value when the settlement stabilizes under the first applied pressure P′1 is denoted as S′. 1,2 ;

[0215] Step 305: Following the methods described in steps 301 to 304, apply load to the j-th borehole 14 for detection, obtain the first displacement value when the j-th load stabilizes, and record it as S. j,1 The second displacement value when the j-th stage of loading stabilizes is denoted as S. j,2 ;

[0216] The j-th loading pressure P′ j The first displacement value when the settlement stabilizes is denoted as S′. j,1 The j-th loading pressure P′ j The second displacement value when the settlement stabilizes is denoted as S′. j,2 Where j is a positive integer, and 1≤j≤J;

[0217] Step 306: Apply the Jth loading pressure P′ to the Jth borehole 14 according to the method described in steps 301 to 304. J Load detection; where P′1, ..., P′ j, ..., P′ J Increase sequentially;

[0218] Step 4: Obtaining the in-situ loess collapsibility coefficient:

[0219] According to the formula Obtain the j-th loading pressure P′ j Collapse coefficient δ of lower in-situ loess s,j Where D is the diameter of the bearing plate 1-1.

[0220] In this embodiment, other related steps can be referred to in Embodiment 2.

[0221] In this embodiment, when j is greater than or equal to 2, the j-th loading pressure P′ j When the pressure is not more than 150 kPa, P′ j -P′ j-1 The value range is 25 kPa to 50 kPa; the j-th loading pressure P′ j When the pressure exceeds 150 kPa, P′ j -P′ j-1 The value range is 50 kPa to 100 kPa.

[0222] In this embodiment, the Jth loading pressure P′ is applied to the Jth borehole 14. J It meets the design requirements.

[0223] The above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Any simple modifications, alterations, and equivalent structural changes made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An in-situ loess collapsibility coefficient testing device, characterized in that: Includes a test probe (1) that extends into the borehole (14), an adjustment component that is set at the top of the borehole (14) and drives the test probe (1) to adjust along the depth direction of the borehole (14), a water supply device (5) set at the top of the borehole (14), and a data acquisition module connected to the test probe (1); The test probe (1) includes a protective shell (1-7), a first hydraulic cylinder (1-8) disposed in the lower part of the protective shell (1-7), a second hydraulic cylinder (1-14) disposed in the upper part of the protective shell (1-7), a load-transfer column (1-13) connected to the second hydraulic cylinder (1-14), and a plurality of force-transfer mechanisms (1-16) connected to the load-transfer column (1-13). The end of the force-transfer mechanism (1-16) is provided with an anchor (1-11) that can be tightly attached to the inner sidewall of the borehole (14). An anchor plate component (1-6) is provided on the anchor (1-11). The plurality of force-transfer mechanisms are arranged along the height of the load-transfer column (1-13) and the depth of the borehole (14). The data acquisition module includes a first displacement meter (1-4) disposed at the bottom of the protective shell (1-7), a second displacement meter (1-10) disposed inside the protective shell (1-7) and used to measure the displacement of the anchor plate component (1-6), and a pin-type displacement meter (1-9) disposed between the lower end of the load transfer column (1-13) and the top surface of the first oil cylinder (1-8). The upper end of the load transfer column (1-13) is connected to the piston rod of the second oil cylinder (1-14), the piston rod of the first oil cylinder (1-8) is connected to the upper end of the loading rod (1-3), and the lower end of the loading rod (1-3) is connected to the bearing plate (1-1). The first displacement gauge (1-4), the second displacement gauge (1-10), and the pin-type displacement gauge (1-9) are all connected to the data acquisition instrument (11), which is connected to the data processing terminal (12). The anchor plate component (1-6) includes a slide rail (1-6-1), an anchor plate (1-6-3) attached to the slide rail (1-6-1), and anchor pins (1-6-2) disposed on one side of the plurality of anchor plates (1-6-3) near the drill hole (14). The upper end of the slide rail (1-6-1) is fixedly connected to the inner side of the anchor (1-11). A groove (1-6-11) is provided on the slide rail (1-6-1). The groove (1-6-11) is arranged along the height direction of the slide rail (1-6-1). A limiting slider (1-6-5) is provided on the other side of the anchor plate (1-6-3) and inserted into the groove (1-6-11). The slide rail (1-6-1) and the limiting slider (1-6-5) slide relative to each other. The pull rope end of the second displacement gauge (1-10) passes through the protective shell (1-7), goes around the reversing wheel (1-6-4), and is then tied to the limit slider (1-6-5).

2. The in-situ loess collapsibility coefficient testing device according to claim 1, characterized in that: The support plate (1-1) includes a support substrate (1-1-1) and a support cover plate (1-1-2) disposed on the top surface of the support substrate (1-1-1). The support substrate (1-1-1) is provided with a plurality of mounting holes, and a cylindrical permeable stone (1-1-13) is placed in the mounting holes. The support cover plate (1-1-2) is provided with a through hole (1-1-22) at the center position. The support substrate (1-1-1) is provided with a threaded interface (1-1-14) at the center position. The lower end of the loading rod (1-3) is provided with a threaded joint. The threaded joint passes through the through hole (1-1-22) and is detachably connected to the threaded interface (1-1-14). The lower end of the loading rod (1-3) is fitted with an anti-loosening nut (1-2). The bearing cover plate (1-1-2) is provided with a plurality of upper limit holes (1-1-21), the center of the upper limit holes (1-1-21) coincides with the center of the cylindrical permeable stone (1-1-13).

3. The in-situ loess collapsibility coefficient testing device according to claim 2, characterized in that: The mounting hole includes an upper large-diameter hole (1-1-11) and a small-diameter hole (1-1-12) communicating with the upper large-diameter hole (1-1-11). The cylindrical permeable stone (1-1-13) is located in the upper large-diameter hole (1-1-11). The inner diameter of the upper large-diameter hole (1-1-11) and the outer diameter of the cylindrical permeable stone (1-1-13) are adapted to each other. The outer diameter of the cylindrical permeable stone (1-1-13) is larger than the inner diameter of the small-diameter hole (1-1-12). The upper limit hole (1-1-21) has the same diameter as the inner diameter of the small diameter hole (1-1-12), and the outer diameter of the cylindrical permeable stone (1-1-13) is larger than the diameter of the upper limit hole (1-1-21).

4. The in-situ loess collapsibility coefficient testing device according to claim 1, characterized in that: The first oil cylinder (1-8) and the second oil cylinder (1-14) are both connected to the hydraulic pump (10) located at the top of the borehole (14) via high-pressure oil pipe (9); The adjustment component includes a tripod (6) set on the top of the borehole (14), a winch (7) set on the tripod (6) and a steel cable (8) with one end wound on the winch (7). The top plate of the protective shell (1-7) is provided with a lifting ring (1-15), and the other end of the steel cable (8) is tied to the lifting ring (1-15).

5. The in-situ loess collapsibility coefficient testing device according to claim 1, characterized in that: The force transmission mechanism (1-16) includes a force transmission block (1-16-1) sleeved on the load transmission column (1-13) and a plurality of transmission rod components arranged along the circumferential direction of the force transmission block (1-16-1), and each transmission rod component is provided with an anchor (1-11) at its end. The force transmission block (1-16-1) has a mounting hole (1-16-11) in the middle and a plurality of receiving grooves (1-16-12) in the circumferential direction. The receiving grooves (1-16-12) penetrate the bottom of the force transmission block (1-16-1). The transmission rod component includes an upper connecting rod (1-16-3) and a horizontal connecting rod (1-16-4) hinged to the upper connecting rod (1-16-3). The horizontal connecting rod (1-16-4) passes through the protective shell (1-7) and the sliding bearing (1-12) embedded in the protective shell (1-7). The upper end of the upper connecting rod (1-16-3) is accommodated in the receiving groove (1-16-12) and is hinged to the force transmission block (1-16-1) through the pin (1-16-2). The lower end of the upper connecting rod (1-16-3) is hinged to one end of the horizontal connecting rod (1-16-4) through the pin (1-16-2). The anchor (1-11) is located at the other end of the horizontal connecting rod (1-16-4).

6. The in-situ loess collapsibility coefficient testing device according to claim 1, characterized in that: The water supply device (5) includes a water tank (5-1) located outside the top of the borehole (14), a water pump (5-3) located in the water tank (5-1), a water pipe (4) connected to the water pump (5-3), and an automatic water level controller (5-2) connected to the water pump (5-3) to control the switch of the water pump (5-3). The water pipe (4) extends into the bottom of the borehole (14) and is equipped with a shower head (3). The automatic water level controller (5-2) is connected to the common probe (2-1), the lower limit probe (2-2), and the upper limit probe (2-3) via a cable (13). The common probe (2-1), the lower limit probe (2-2), and the upper limit probe (2-3) are located inside the bottom of the borehole (14).

7. A method for testing the in-situ loess collapsibility coefficient using the apparatus as described in claim 1, characterized in that, The method includes the following steps: Step 1: Formation of two boreholes and placement of the in-situ testing device for loess collapsibility: Step 101: Clean up the debris on the surface of the loess in the original location, and use the dry drilling method to drill holes to the designed depth on the surface of the loess in the original location to obtain two holes (14). Step 102: Level the soil at the bottom of the borehole (14) and lay medium sand at the bottom of the borehole (14); Step 103: Check the in-situ loess collapsibility coefficient testing device to ensure that all parts of the device are functioning properly. Step 104: Lower the test probe (1) along the borehole (14) using the adjustment component until the bottom of the test probe (1) is 3cm to 5cm from the bottom of the borehole (14); and lower the shower head (3) to a position 15cm to 25cm from the bottom of the borehole (14) using the water pipe (4) in the water supply device (5). Lower the common probe (2-1), lower limit probe (2-2), and upper limit probe (2-3) through cable (13) until the bottom of the common probe (2-1) and lower limit probe (2-2) is 5cm away from the bottom of the hole, and the upper limit probe (2-3) is 15cm away from the bottom of the borehole (14); Step 105: Connect the connection ends of the first displacement gauge (1-4), the pin-type displacement gauge (1-9), and the second displacement gauge (1-10) extending out of the top of the borehole (14) to the data acquisition instrument (11); and connect the first hydraulic cylinder (1-8) and the second hydraulic cylinder (1-14) to the hydraulic pump (10) through the high-pressure oil pipe (9); wherein, the data acquisition instrument (11) is connected to the data processing terminal (12); Step 2: Adjustment of the in-situ loess collapsibility coefficient testing device in a borehole: Step 201: The hydraulic pump (10) supplies hydraulic oil to the second cylinder (1-14) through the high-pressure oil pipe (9) to pressurize it, so that the piston rod of the second cylinder (1-14) extends. The extension of the piston rod of the second cylinder (1-14) drives the anchor (1-11) to be tightly attached to the borehole wall (14) through the force transmission mechanism (1-16). The anchor plate component (1-6) is anchored to the borehole wall (14). Among them, the test probe (1) and the borehole (14) are coaxially arranged. Step 202: The steel cable (13) in the adjustment component is extended. The test probe (1) is placed statically without the tension of the steel cable (13). The pin-type displacement gauge (1-9) detects the third displacement signal and sends it to the acquisition instrument (11). The acquisition instrument (11) sends the acquired third displacement to the data processing terminal (12) until the displacement change of the third displacement received by the data processing terminal (12) within 2 consecutive hours is less than 0.10 mm / h. Step 203: The hydraulic pump (10) supplies hydraulic oil to the first cylinder (1-8) through the high-pressure oil pipe (9) to pressurize it, so that the piston rod of the first cylinder (1-8) extends. The extension of the piston rod of the first cylinder (1-8) drives the bearing plate (1-1) to move downward through the loading rod (1-3) until the bottom surface of the bearing plate (1-1) is in contact with the bottom of the drill hole (14); wherein, the loading pressure applied by the bearing plate (1-1) to the bottom of the drill hole (14) is zero. Step 3: Loading test of the soil at the bottom of a borehole: Step 301: The piston rod of the first cylinder (1-8) continues to extend, so that the bottom surface of the bearing plate (1-1) applies the first stage of loading pressure to the bottom of the drill hole (14). Among them, the first stage loading pressure The value range is 25 kPa to 50 kPa; Step 302: Apply the first-stage loading pressure During the process, the first displacement signal detected by the first displacement gauge (1-4) and the second displacement signal detected by the second displacement gauge (1-10) are sent to the data acquisition instrument (11). The data acquisition instrument (11) collects the first displacement signal and the second displacement signal in real time and sends them to the data processing terminal (12). The data processing terminal (12) receives the first displacement value and the second displacement value. Step 303: If the difference between the first displacement value and the second displacement value received by the data processing terminal (12) is less than 0.10 mm / h within 2 consecutive hours, then the first-stage loading is stable. The first displacement value at which the first-stage loading is stable is obtained and recorded as... The second displacement value when the first stage of loading stabilizes is recorded as... ; Step 304: Apply the k-th level loading pressure according to the methods described in steps 301 to 303. And obtain the first displacement value when the k-th stage of loading is stable and record it as . The second displacement value when the k-th stage of loading stabilizes is denoted as... ; Step 305: Apply the nth level loading pressure as required by the design, following the methods described in steps 301 to 303. And obtain the first displacement value when the nth level of loading is stable and record it as The second displacement value when the nth stage of loading stabilizes is denoted as... Where k and n are positive integers, and 1 ≤ k ≤ n; Step 4: Loading test when the soil at the bottom of a borehole is saturated with water: Step 401: While maintaining the applied nth level loading pressure, inject water into the soil at the bottom of the borehole (14) through the water supply device (5) until the soil is saturated; Step 402: When the soil at the bottom of borehole (14) settles, follow the methods described in steps 302 and 303 until the difference between the first and second displacement values ​​is less than 0.10 mm / h over a continuous 2 hours, at which point the settlement is considered stable. Obtain the first displacement value at which the settlement is stable and record it as... The second displacement value when the settlement stabilizes is recorded as... ; Step 5: Loading test when the soil at the bottom of another borehole is saturated with water: Step 501: Apply the first-stage loading pressure according to the methods described in steps 301 to 303. Until the first stage of loading is stable, water is injected into the soil at the bottom of another borehole (14) through the water supply device (5) until the soil is saturated; Step 502: Maintain the applied first-level loading pressure and follow the methods described in steps 302 to 303 until the difference between the first and second displacement values ​​is less than 0.10 mm / h over a continuous 2 hours. Obtain the first displacement value when the soil stabilizes under the first-level loading and record it as... The second displacement value when the soil reaches stability under the first stage of saturated loading is recorded as... ; Step 503: Following the methods described in steps 501 to 503, apply the k-th level loading pressure to the saturated soil. Next, obtain the first displacement value when the soil reaches stability under the k-th level of saturated loading and record it as... The second displacement value when the soil reaches stability under the k-th level of saturated loading is denoted as... ; Step 504: Apply the nth level of loading pressure to the saturated soil according to the methods described in steps 501 to 503. Next, obtain the first displacement value when the soil reaches stability under the nth level of saturated loading and record it as... The second displacement value when the soil reaches stability under the k-th level of saturated loading is denoted as... ; Step Six: Obtaining the in-situ loess collapsibility coefficient: Step 601, Judgment Check if the condition is met. If not, proceed to step 602; if met, proceed to step 603. Step 602: Follow the methods described in steps one through five until... Established; Step 603, according to and according to After being corrected ; according to The in-situ loess collapsibility coefficient was obtained. ;in, The diameter is that of the bearing plate (1-1).

8. A method for testing the in-situ loess collapsibility coefficient using the apparatus as described in claim 1, characterized in that, The method includes the following steps: Step 1: Formation of multiple boreholes and placement of in-situ testing equipment for loess collapsibility: Step 101: Clear debris from the in-situ loess surface and use dry drilling to drill holes to the designed depth in the in-situ loess surface to obtain... There are 14 boreholes; the distance between two adjacent boreholes (14) is 2.0m to 2.5m. It is a positive integer not less than 3; Step 102, Leveling The soil at the bottom of borehole (14), and in The bottom of each borehole (14) is covered with medium sand; the thickness of the medium sand is 10mm to 15mm. Step 103: Check the in-situ loess collapsibility coefficient testing device to ensure that all parts of the device are functioning properly. Step 104, in In-situ testing devices for loess collapsibility were placed in each borehole (14); the specific process for placing the in-situ testing device for loess collapsibility in any one borehole (14) is as follows: First, the test probe (1) is lowered along the borehole (14) using the adjustment component until the bottom of the test probe (1) is 3cm to 5cm from the bottom of the borehole (14); then the shower head (3) is lowered to a position 15cm to 25cm from the bottom of the borehole (14) using the water pipe (4) in the water supply device (5); then the common probe (2-1), lower limit probe (2-2), and upper limit probe (2-3) are lowered using the cable (13) until the bottom of the common probe (2-1) and lower limit probe (2-2) are 5cm from the bottom of the borehole, and the upper limit probe (2-3) is 15cm from the bottom of the borehole (14); Then, the connecting ends of the first displacement gauge (1-4), the pin-type displacement gauge (1-9), and the second displacement gauge (1-10) extending out of the top of the borehole (14) are all connected to the data acquisition instrument (11); and the first oil cylinder (1-8) and the second oil cylinder (1-14) are both connected to the hydraulic pump (10) through the high-pressure oil pipe (9); wherein, the data acquisition instrument (11) is connected to the data processing terminal (12); Step Two Adjustment of the in-situ loess collapsibility coefficient testing device in each borehole: The adjustment process for the in-situ loess collapsibility coefficient testing device in each borehole is the same. The specific adjustment process for any one borehole's in-situ loess collapsibility coefficient testing device is as follows: Step 201: The hydraulic pump (10) supplies hydraulic oil to the second cylinder (1-14) through the high-pressure oil pipe (9) to pressurize it, so that the piston rod of the second cylinder (1-14) extends. The extension of the piston rod of the second cylinder (1-14) drives the anchor (1-11) to be tightly attached to the borehole wall (14) through the force transmission mechanism (1-16). The anchor plate component (1-6) is anchored to the borehole wall (14). Among them, the test probe (1) and the borehole (14) are coaxially arranged. Step 202: The steel cable (13) in the adjustment component is extended. The test probe (1) is placed statically without the tension of the steel cable (13). The pin-type displacement gauge (1-9) detects the third displacement signal and sends it to the acquisition instrument (11). The acquisition instrument (11) sends the acquired third displacement to the data processing terminal (12) until the displacement change of the third displacement received by the data processing terminal (12) within 2 consecutive hours is less than 0.10 mm / h. Step 203: The hydraulic pump (10) supplies hydraulic oil to the first cylinder (1-8) through the high-pressure oil pipe (9) to pressurize it, so that the piston rod of the first cylinder (1-8) extends. The extension of the piston rod of the first cylinder (1-8) drives the bearing plate (1-1) to move downward through the loading rod (1-3) until the bottom surface of the bearing plate (1-1) is in contact with the bottom of the drill hole (14); wherein, the loading pressure applied by the bearing plate (1-1) to the bottom of the drill hole (14) is zero. Step 3: Supply via the support plate Gradual loading and monitoring of soil at the bottom of each borehole: Step 301: The piston rod of the first cylinder (1-8) continues to extend, so that the bottom surface of the bearing plate (1-1) applies the first loading pressure to the bottom of the first drill hole (14). The first loading pressure The value range is 25 kPa to 50 kPa; Step 302: Apply the first loading pressure During the process, the first displacement signal detected by the first displacement gauge (1-4) and the second displacement signal detected by the second displacement gauge (1-10) are sent to the data acquisition instrument (11). The data acquisition instrument (11) collects the first displacement signal and the second displacement signal in real time and sends them to the data processing terminal (12). The data processing terminal (12) receives the first displacement value and the second displacement value. Step 303: If the difference between the first displacement value and the second displacement value received by the data processing terminal (12) is less than 0.10 mm / h within 2 consecutive hours, then the first loading is stable. Obtain the first displacement value at the time of the first loading stabilization and record it as... The second displacement value when the first load stabilizes is recorded as... ; Step 304: Inject water into the soil at the bottom of the first borehole (14) through the water supply device (5) until the soil is saturated; maintain the first loading pressure applied. Below, the soil at the bottom of the first borehole (14) settles. According to the judgment method in step 303, the settlement is stable; obtain the first loading pressure. The first displacement value when the settlement stabilizes is recorded as follows: The first load pressure The second displacement value when the settlement stabilizes is recorded as follows. ; Step 305: Following the methods described in steps 301 to 304, give the first... The borehole (14) was loaded and tested to obtain the first result. The first displacement value when the loading stabilizes is recorded as... , No. The second displacement value when the loading is stable is recorded as follows. ; No. Load pressure The first displacement value when the settlement stabilizes is recorded as follows: , No. Load pressure The second displacement value when the settlement stabilizes is recorded as follows. ;in, It is a positive integer, and ; Step 306: Following the methods described in steps 301 to 304, give the first... The first borehole (14) was applied Load pressure Loading detection; among which, ,..., ,..., Increase sequentially; Step 4: Obtaining the in-situ loess collapsibility coefficient: According to the formula , obtained the Load pressure Collapse coefficient of lower in-situ loess ;in, The diameter is that of the bearing plate (1-1).

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