A method for backfilling grouting construction in sandy cobble stratum

Abstract

The present application provides a kind of sand pebble stratum retreating type grouting construction method, the grouting construction method is: using angle measuring device measures and adjusts the drilling angle of drill pipe, using drilling device carries out grouting hole operation;Several cylindrical slurry outlet sections are connected into slurry outlet pipe by connecting sleeve, connecting sleeve includes support pipe, sealing inner ring and sealing outer ring, slurry outlet pipe is inserted into grouting hole with steel pipe, sealing outer ring and steel pipe can be mutually attached when slurry outlet pipe is inserted, slurry outlet pipe is inserted into grouting hole bottom when waiting, steel pipe is extracted, sealing outer ring is closely attached with grouting hole wall;Grouting pipe is inserted into grouting hole bottom along the cavity in the middle of slurry outlet pipe;By retreating type grouting method, grouting hole is sequentially carried out localized grouting reinforcement.The grouting method of the present application can solve the technical problems in the prior art, such as grouting hole grout plugging, unsuitable for oblique downward sand pebble drilling grouting, and inappropriate adjustment of localized size during sand pebble stratum retreating type grouting reinforcement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground engineering, in particular to a retreating type grouting construction method for sand-pebble stratum. BACKGROUND

[0002] Rail transit construction often encounters many adverse geological conditions such as sand-pebble stratum, and engineering geological disasters occur from time to time, which has many constraints on the safety and efficient development of engineering construction. Sand-pebble stratum has the characteristics of loose structure, poor cementation ability, weak self-stability, strong permeability, and small cohesion, and belongs to a typical mechanically unstable stratum. In the treatment process of sand-pebble stratum, the most commonly used method is grouting treatment. The principle of this treatment technology is relatively simple, that is, by injecting cementing material in the form of slurry into the target stratum, the mechanical properties of the stratum are changed, so as to reduce the permeability and improve the strength of the stratum. Due to the special nature of sand-pebble, the particle size is different, and it is difficult to grout and reinforce. At present, the retreating type grouting is often used, but there are still some technical problems: for example, it is necessary to drill once to the end of the designed area, and the drill rod is often stuck; during grouting, the slurry has strong fluidity before it is coagulated, and the diffusion area of the slurry is uncontrollable; after the slurry diffuses, it may flow back into the front section of the retreating direction and coagulate, making it difficult to retreat the drill rod; when the grouting pipe retreats to the next grouting area, the slurry diffusion channel around it is blocked by the slurry diffused by the previous grouting section, the grouting diffusion area is not enough, and the reinforcement effect is affected.

[0003] The invention patent with the publication number CN117721805A proposes a retreating type localized grouting method and structure for sand-pebble stratum, which can achieve the effect of filling sand-pebble stratum and improve the permeability of the stratum. However, the method has the following shortcomings: (1) it is necessary to inject sealing pipe cement-water glass double liquid slurry around the slurry outlet pipe, which is affected by the complex geological conditions of sand-pebble stratum, and it is inevitable that the slurry will exosmosis into the sand-pebble stratum during this process, which may cause the phenomenon of blocking the localized slurry diffusion channel in the later period; (2) when the drill hole is inclined downward, the grouting pressure is difficult to control accurately due to the influence of the gravity factor of the slurry, and the double liquid slurry injection process around the slurry outlet pipe will diffuse to both sides of the hole, seriously blocking the diffusion of the localized slurry in the later period, so this patent method is not suitable for inclined downward sand-pebble drill hole grouting; (3) the localized size of the grouting section cannot be changed, and the sealing period of the slurry outlet pipe is difficult to adjust appropriately according to different working conditions. SUMMARY

[0004] The present application provides a retreating type grouting construction method for sand-pebble stratum to solve the technical problems of slurry plugging in the grouting hole, unsuitability for inclined downward sand-pebble drill hole grouting, and difficulty in adjusting the localized size in the process of retreating type grouting and reinforcement of sand-pebble stratum in the prior art.

[0005] In order to achieve the above-mentioned purpose, the specific scheme adopted by the present application is:

[0006] A sand pebble stratum retreating type grouting construction method mainly comprises the following steps:

[0007] S1, using a total station to determine the position of a sand pebble stratum grouting reinforcement drilling hole, fixing a drill rod of a drilling device to an angle measuring device with adjustable height, measuring and adjusting the drilling angle of the drill rod by using the angle measuring device, and performing opening operation by using the drilling device;

[0008] S2, after the opening is completed, the drill bit of the drilling device is taken out, an orifice pipe is inserted into the hole, the orifice is closed by using cement-water glass double-liquid slurry sealing material, and a flange plate is installed at the orifice;

[0009] S3, a steel pipe is arranged outside the drill bit of the drilling device, the angle of the drill rod is adjusted in real time during drilling, and the drill bit and the steel pipe are ensured to be advanced cooperatively, and drilling is performed to the target depth, that is, a grouting hole is obtained, and the drilling device is taken out;

[0010] S4, a plurality of cylindrical grouting sections are connected into a grouting pipe with a length not less than the depth of the grouting hole through connecting sleeves, the connecting sleeve comprises a support pipe with threaded sections at two ends, a sealing inner ring coaxially arranged inside the support pipe, and a sealing outer ring coaxially arranged outside the support pipe, the grouting section is threadedly connected with the threaded section of the support pipe, the outer diameter of the sealing outer ring is greater than the diameter of the grouting hole, and the inner diameter of the sealing inner ring is slightly greater than the outer diameter of the grouting pipe; the grouting pipe is inserted into the steel pipe, the sealing outer ring and the steel pipe can be closely attached and smoothly slide when the grouting pipe is inserted, the steel pipe is pulled out when the grouting pipe is extended to the bottom of the grouting hole, and the sealing outer ring is closely attached to the wall of the grouting hole;

[0011] S5, the grouting pipe is inserted into the bottom of the grouting hole along the cavity composed of the grouting section and the sealing inner ring;

[0012] S6, the grouting hole is sequentially subjected to localized grouting reinforcement by using the retreating type grouting method.

[0013] Further, the angle measuring device comprises a base, a positioning pipe with an overall C-shaped structure arranged on the base, an electronic digital angle gauge with magnetism placed on the base and closely attached to the positioning pipe, and three height-adjustable positioning legs hinged to the base;

[0014] The arc-shaped sliding grooves are symmetrically arranged at both ends of the positioning pipe on the base; the drill rod can be placed in the positioning pipe in parallel through the opening arranged in the axial direction of the positioning pipe; the middle part of the contact surface between the positioning pipe and the base is provided with a limiting unit, and both ends are provided with sliding units capable of sliding along the corresponding arc-shaped sliding grooves; the sliding units are symmetrically arranged with the limiting unit as the center; the limiting unit and the sliding unit have the same structure and both include a vertical fixing bolt and a fixing nut arranged on the vertical fixing bolt; one end of the vertical fixing bolt is fixedly connected with the positioning pipe, and the other end extends to below the base through the base; when the angle of the drill rod is adjusted, the positioning pipe is rotated, the sliding unit moves along the arc-shaped sliding groove with the limiting unit as the center, when the positioning pipe is rotated to the target angle, the fixing nut is tightened to abut against the base, and then the positioning pipe can be fixed.

[0015] Further, the positioning pipe is further provided with a positioning unit capable of positioning the drill rod placed in the positioning pipe; the positioning unit includes a clamping nut welded on the positioning pipe and a clamping bolt in threaded connection with the clamping nut; one end of the clamping bolt extends into the cavity of the positioning pipe.

[0016] Further, the base is circular, and the vertical fixing bolts in the limiting unit pass through the center of the base.

[0017] Further, two fixing nuts are arranged on each vertical fixing bolt and are arranged on the upper and lower sides of the base respectively.

[0018] Further, three pairs of circular-arc-shaped limiting hoops are fixed on the bottom surface of the base, and the positioning legs are hinged to the base through the limiting hoops.

[0019] Further, a conical positioning leg is arranged at the lower part of the positioning leg.

[0020] Further, in step S4, a plurality of slurry outlets are uniformly arranged on the peripheral surface of the slurry outlet section.

[0021] Further, in step S6, the injection pressure control value is 0.5-1.0 MPa, and the injection pressure is continued to be injected for a period of time after the injection pressure reaches the final pressure state, and then the injection is stopped.

[0022] Further, in step S6, the connecting sleeve is used as the domain position during the localized grouting reinforcement.

[0023] The technical scheme of the present application has the following beneficial effects:

[0024] (1) In the retreating type localized grouting method suitable for sand and pebble stratum provided by the present application, the length of the slurry outlet pipe can be set by using the slurry outlet section and the connecting sleeve section, and by connecting the connecting sleeve with slurry outlet sections of different lengths, localized grouting reinforcement of different lengths can be realized, and the problem that the anchor point is difficult to be appropriately adjusted according to the working condition in the prior art is solved.

[0025] (2) The method for different inclination angle of sand-pebble stratum provided by the application can isolate the slurry of the closed grouting section by the sealing outer ring and the sealing inner ring of the connecting sleeve, realize the effect of different length of localized reinforcement grouting compaction filling, and solve the problem of plugging the late-stage localized slurry diffusion channel in the prior art.

[0026] (3) The method for different inclination angle of sand-pebble stratum provided by the application can effectively isolate the grouting slurry of the closed grouting, compared with the prior art, without the need to inject cement-water glass double-liquid slurry and related grouting steps, and can be applied to different inclination angle of drilling conditions, saving grouting materials, achieving the effect of simple operation, carbon reduction and efficient construction, and having the characteristics of clear process, easy operation, high popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of an angle measuring device.

[0028] Figure 2 It is a structural schematic diagram of an angle measuring device.

[0029] Figure 3 It is a structural schematic diagram of an angle measuring device.

[0030] Figure 4 It is a schematic diagram when opening a hole.

[0031] Figure 5 It is a schematic diagram of setting an orifice tube and a flange plate at the orifice.

[0032] Figure 6 It is a schematic diagram of the drilling device cooperating with the steel pipe to drill.

[0033] Figure 7 It is a schematic diagram after installing the slurry outlet pipe.

[0034] Figure 8 It is a schematic diagram after the steel pipe is pulled out.

[0035] Figure 9 It is a schematic diagram of the grouting pipe inserted into the slurry outlet pipe.

[0036] Figure 10 It is a schematic diagram of the grouting reinforcement at the bottom area of the grouting hole.

[0037] Figure 11 It is a schematic diagram of the grouting reinforcement at the middle area of the grouting hole.

[0038] Figure 12 It is a sectional view of the connecting sleeve.

[0039] Figure 13 is a plan view of the connecting sleeve.

[0040] Figure 14 is a plan view of the sand-pebble stratum after grouting reinforcement.

[0041] Illustration mark: 1, positioning pipe, 1-1, clamping bolt, 1-2, clamping nut, 1-3, vertical fixing bolt, 1-4, fixing nut, 1-5, opening, 2, electronic digital display angle gauge, 3, base, 3-1, arc-shaped sliding groove, 3-2, limiting hoop, 4, positioning leg, 4-1, limiting steel bar, 4-2, height adjusting steel bar, 4-3, connecting pipe, 4-4, conical positioning leg, 4-5, height fixing bolt, 4-6, height fixing nut, 5, sand-pebble stratum, 6, drilling device, 7, orifice pipe, 8, flange plate, 9, steel pipe, 10, grouting section, 10-1, grouting opening, 11, connecting sleeve, 11-1, sealing outer ring, 11-2, threaded section, 11-3, supporting pipe, 11-4, sealing inner ring, 11-5, grouting pipe reserved hole, 12, grouting pipe, 13, bottom grouting reinforcement section, 14, middle grouting reinforcement section. DETAILED DESCRIPTION

[0042] The technical solutions of the present application will be described clearly and completely below in combination with specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0043] In the description of the present application, it should be understood that the terms "upper", "lower" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the protection scope of the present application.

[0044] When a tunnel is constructed by underground excavation in some cities, the geological distribution is mainly miscellaneous fill, silty clay, silt, silty sand, medium sand, sand-pebble, strongly weathered mudstone and moderately weathered mudstone. The tunnel construction often passes through the sand-pebble stratum, the pebbles are gray and grayish yellow, filled with silty sand, the pebble components are mainly quartzite and granite, in round and sub-round shapes, with a layer thickness of 2-4.1 m. After excavation, the self-stability is very poor, easy to collapse, the ground settlement is difficult to control, and the construction cannot be carried out.

[0045] The present application discloses a sand-pebble stratum retreating type grouting construction method, mainly comprising the following steps:

[0046] S1, the position of the sand and gravel stratum grouting reinforcement drilling is determined by using a total station, the drill rod of the drilling device is fixed to the height-adjustable angle measuring device, the drilling angle of the drill rod is measured and adjusted by using the angle measuring device, so as to ensure the accuracy of the opening direction and the later drilling, and the opening operation is performed by using the drilling device;

[0047] S2, after the opening is completed, the drill bit of the drilling device 6 is taken out, the orifice pipe 7 is inserted into the hole, the orifice is closed by using the cement-water glass double slurry sealing material, and the flange plate 8 is installed at the orifice;

[0048] S3, the steel pipe 9 is sleeved on the drilling device 6, the angle of the drill rod is adjusted in real time during drilling, and the drill bit is ensured to be cooperatively advanced with the steel pipe 9, and after the drill bit and the steel pipe 9 jointly reach the designed depth, the grouting hole is obtained, the drill bit is removed, the inclination and position of the grouting hole are detected, and the drilling device 6 is removed after the design requirements are met;

[0049] S4, a plurality of cylindrical grouting sections 10 are connected into a grouting pipe with a length not less than the grouting hole depth through a connecting sleeve 11, the grouting sections 10 are provided with annularly distributed grouting outlets 10-1 on the surfaces, and the axes of the grouting outlets 10-1 are distributed in a cross-inclined manner; the connecting sleeve 11 comprises a support pipe 11-3 with threaded sections 11-2 at two ends, a sealing inner ring 11-4 coaxially arranged in the support pipe 11-3, and a sealing outer ring 11-1 coaxially arranged outside the support pipe 11-3, the grouting sections 10 are threadedly connected with the threaded sections 11-2 of the support pipe 11-3, the outer diameter of the sealing outer ring 11-1 is greater than the diameter of the grouting hole, the grouting pipe is reserved in the inner cavity of the sealing inner ring 11-4, the diameter of the grouting pipe is slightly larger than that of the grouting pipe 12, the grouting pipe 12 can freely move in the connecting sleeve 11, the sealing inner ring 11-4 can separate the grouting liquid in the current grouting section, the grouting quality of each grouting section is ensured, the grouting pipe is inserted into the steel pipe 9, the outer sealing outer ring 11-1 is tightly attached to the steel pipe 9, the steel pipe 9 is pulled out when the grouting pipe extends to the bottom of the drilling hole, and the sealing outer ring 11-1 is tightly attached to the wall of the grouting hole;

[0050] S5, the grouting pipe 12 is inserted along the grouting pipe, extends to the bottom of the drilling hole through the grouting pipe reserved hole 11-5, and is marked at the side wall of the grouting pipe 12 when passing through the connecting sleeve 11, so as to control the position of the grouting pipe opening during the grouting stage;

[0051] S6, the drilling hole is sequentially grouted and reinforced by using the retreating grouting method, the grouting pipe is retreated to the next grouting section for grouting after the bottom grouting reinforcement section completes the grouting reinforcement, and the grouting and reinforcement of each section are completed.

[0052] It should be noted that, please refer to Figures 1 to 3 The angle measuring device in the application comprises a base 3, a positioning pipe 1 in a C-shaped structure arranged on the base 3, a magnetic electronic digital angle gauge 2 placed on the base 3 and closely attached to the positioning pipe 1, and three height-adjustable positioning legs 4 hinged to the base 3.

[0053] A clamping nut 1-2 is mounted on the outer surface of the top of the positioning pipe 1, a clamping bolt 1-1 vertically penetrates through the clamping nut 1-2 and extends into the interior of the positioning pipe 1, and the end of the clamping bolt 1-1 can be in direct contact with the drill rod.

[0054] The drill rod is placed in the interior of the positioning pipe 1 through the opening 1-5 of the positioning pipe, the drill rod is placed at the bottom of the positioning pipe 1, and the drill rod is parallel to the axis of the positioning pipe 1.

[0055] An arc-shaped sliding groove 3-1 is formed in the base 3 in the thickness direction. A limiting unit is arranged at the central position of the contact surface of the positioning pipe 1 and the base 3, and sliding units capable of sliding along the corresponding arc-shaped sliding grooves 3-1 are arranged at the two ends of the limiting unit, the sliding units are symmetrically arranged with the limiting unit as the center, the limiting unit and the sliding unit have the same structure, and both comprise a vertical fixing bolt 1-3 and a fixing nut 1-4 arranged on the vertical fixing bolt 1-3, one end of the vertical fixing bolt 1-3 is fixedly connected with the positioning pipe 1, and the other end extends to below the base 3 through the base 3. When the angle of the drill rod is adjusted, the positioning pipe 1 is rotated, the sliding unit moves along the arc-shaped sliding groove 3-1 with the limiting unit as the center point, when it is rotated to the target angle, the fixing nut 1-4 is tightened to abut against the base 3, and the positioning pipe 1 can be fixed.

[0056] Specifically, the vertical fixing bolt 1-3 in the limiting unit extends to below the base 3 through the center of the base 3, and the fixing nut 1-4 is arranged on the vertical fixing bolt 1-3 and distributed on the upper and lower sides of the base 3.

[0057] The vertical fixing bolt 1-3 in the sliding unit vertically penetrates through the arc-shaped sliding groove 3-1, the vertical fixing bolt 1-3 is fixed by the fixing nut 1-4 arranged on the two sides of the base 3, the axial direction of the positioning pipe 1 and the drill rod can be adjusted to be consistent with the drilling direction through the arc-shaped sliding groove 3-1, and then the vertical fixing bolt 1-3 is fixed by the cooperation of the fixing nut 1-4 and the base 3.

[0058] The arc-shaped limiting hoops 3-2 are fixed on the lower surface of the base 3, every two limiting hoops 3-2 form a group, and there are three groups in total; the limiting hoops 3-2 are made of steel bars or steel plates.

[0059] The lower part of the base 3 is provided with a positioning leg 4, which comprises a limiting steel bar 4-1, an adjusting steel bar 4-2, a connecting pipe 4-3, and a tapered positioning leg 4-4. The limiting steel bar 4-1 is vertically welded with the adjusting steel bar 4-2. At least one pair of bolt holes is arranged on the connecting pipe 4-3, and each pair of bolt holes is symmetrically arranged on both sides of the connecting pipe 4-3. A height fixing nut 4-6 is welded on the outer periphery of the bolt hole. The adjusting steel bar 4-2 is inserted into the connecting pipe 4-3, and the height of the positioning leg 4 is adjusted by the length of the adjusting steel bar 4-2 in the connecting pipe 4-3. After the height is adjusted to the target height, the height fixing bolt 4-5 matched with the height fixing nut 4-6 can fix the adjusting steel bar 4-2 adjusted to the target height.

[0060] The limiting steel bar 4-1 is vertically arranged in the limiting hoop 3-2, and the setting angle of the positioning leg 4 is adjusted by rotating the limiting steel bar 4-1.

[0061] The lower part of the connecting pipe 4-3 in the positioning leg 4 is a tapered positioning leg 4-4, which can be stably supported on the ground and other working platforms, avoiding the sliding of the support rod and affecting the positioning stability and accuracy of the positioning support 4.

[0062] The drilling angle of the drill rod is measured by using an angle measuring device, which specifically includes the following steps:

[0063] 1) Connecting the positioning pipe 1 and the base 3: connecting the vertical fixing bolt 1-3 in the limiting unit and the base 3, and fixing the vertical fixing bolt 1-3 on both sides of the base 3 with the fixing nut 1-4. The top of the positioning pipe 1 is provided with the clamping bolt 1-1 according to the position of the clamping nut 1-2,

[0064] 2) Connecting the positioning leg 4: inserting the adjusting steel bar 4-2 into the connecting pipe 4-3, adjusting the height of the adjusting steel bar 4-2 in the lower connecting pipe 4-3, and fixing the height fixing bolt 4-5;

[0065] 3) Position adjustment of the base 3: placing the drill rod in the positioning pipe 1 through the opening 1-5 of the positioning pipe 1, vertically penetrating the vertical fixing bolt 1-3 in the sliding unit through the arc-shaped sliding groove 3-1, adjusting the direction of the positioning pipe 1 to ensure that the drill rod is parallel to the axis of the positioning pipe 1, fixing the drill rod through the clamping bolt 1-1 at the top of the positioning pipe 1, vertically fixing the limiting steel bar 4-1 in the limiting hoop 3-2, appropriately adjusting the angle of the positioning leg 4, and adjusting the length of the adjusting steel bar 4-2 to enable the base 3 to be kept in the appropriate position;

[0066] 4) Adjustment of the position of the drill rod and the center of the drill hole: adjusting the position of the drill rod to the center of the drill hole, and finely adjusting the device by adjusting the angle of the positioning leg 4 to ensure that the drill rod effectively corresponds to the position of the center of the drill hole;

[0067] 5) Drilling rod inclination measurement, and adjusting the drilling direction: place the electronic digital angle gauge 2 closely on the surface of the positioning pipe 1 on the base 3, read the data of the electronic digital angle gauge 2, determine whether the design limit and engineering requirements are met, if not, adjust the drilling direction of the drilling rod until it is satisfied.

[0068] The technical solutions of the present application will be described in detail below in combination with specific embodiments.

[0069] Embodiment 1

[0070] A sand-pebble stratum retreating type grouting construction method mainly comprises the following steps:

[0071] Step one, determine the construction range of the grouting hole, calculate the coordinate position of the hole according to the coordinate of the control point and the layout scheme of the sand-pebble grouting hole, and use the total station to determine the hole position;

[0072] Step two, before the hole is opened, use the angle measuring device to determine the angle of the sand-pebble stratum grouting hole, fix the position of the drilling rod, and use the drilling device to open the grouting hole, the grouting hole has a diameter of 63mm, the drilling angle of the grouting hole is 30° (the drilling angle refers to the angle between the drilling direction of the drilling machine and the horizontal plane), the grouting hole is arranged in a plum blossom shape in the cross section, when the hole is opened, low pressure and slow rotation are used, after the hole is opened, the drilling angle of the drilling rod is measured by using the angle measuring device, and the drilling angle of the drilling rod is adjusted according to the result to ensure the accuracy of the opening direction and the later drilling;

[0073] Step three, after the hole is opened, the drilling device 6 is taken out from the hole, the orifice pipe 7 is inserted into the hole, the hemp yarn is wound on the orifice pipe 7 close to the orifice, the cement-water glass double liquid slurry is applied, after the orifice pipe 7 is sent into the hole, the cement-water glass double liquid slurry is hardened, combined with the surrounding sand-pebble, plays a sealing role, and the flange plate 8 is installed at the orifice;

[0074] Step four, a steel pipe 9 is additionally arranged outside the drilling device 6, and the two are pushed forward during the drilling process, the drilling device 6 and the steel pipe 9 maintain a distance of 30cm in the hole, the angle of the drilling rod is measured by using the angle measuring device during the drilling process to effectively control the drilling deviation rate, the drilling rod is re-measured every 3.5m during the drilling process, and the debris in the hole is cleaned, after the hole reaches the design depth of 7m, the grouting hole is obtained, the inclination and position of the grouting hole are detected, and the drilling device 6 is taken out after the design requirements are met;

[0075] Step five, a plurality of cylindrical grouting sections 10 are connected into a grouting pipe with a length not less than the depth of the grouting hole through a connecting sleeve 11, a plurality of grouting openings 10-1 are uniformly distributed on the grouting section 10, the diameter of the grouting opening 10-1 is 6mm, the grouting openings 10-1 are distributed in a ring shape along the axial direction of the grouting section 10 with a spacing of 5cm, and the grouting openings 10-1 are staggered.

[0076] Step six, insert the slurry outlet pipe into the steel pipe 9, before insertion, evenly apply a small amount of lubricant on the inner surface of the steel pipe 9, tightly seal the outer ring 11-1 with the steel pipe 9, when the slurry outlet pipe is inserted into the bottom of the drill hole, pull out the steel pipe 9, tightly seal the outer ring 11-1 with the wall of the grouting hole; it should be noted that the Ф32mm grouting pipe 12 is inserted along the slurry outlet pipe, inserted into the bottom of the drill hole through the grouting pipe reserved hole 11-5, when passing through the connecting sleeve 11, mark on the wall of the grouting pipe 12, which is convenient for controlling the position of the grouting pipe opening during the grouting stage;

[0077] Step seven, sequentially carry out regional grouting reinforcement on the drill hole by the backward grouting method, the ratio of cement to water is 1:1, the cement grade is 42.5, the grouting pressure control value is 0.5-1.0MPa, when the grouting pressure reaches the final pressure state, continue grouting for 10min and then stop grouting, during which the grouting pressure should be ensured not to increase suddenly, the grouting reinforcement operation is carried out by controlling the grouting pressure;

[0078] Step eight, after the bottom grouting reinforcement section completes grouting reinforcement, the grouting pipe retreats to the next grouting section for grouting, until the grouting reinforcement of each section is completed.

[0079] The above is only the preferred embodiment of the present application, and is not limited in any form. Any equivalent transformation or modification according to the essence of the present application should be covered within the protection scope of the present application.

Claims

1. A method for back-grouting construction in a sandy cobble stratum, characterized in that, Mainly include the following steps: S1, using total station to determine the position of sand and gravel stratum grouting reinforcement drilling, the drill pipe of drilling device is fixed to the height adjustable angle measuring device, using angle measuring device to measure and adjust the drilling angle of drill pipe, using drilling device to carry out opening operation; S2, after the opening is completed, the drill bit of the drilling device is taken out, the orifice pipe is inserted into the hole, the orifice is closed with cement-silicate double liquid slurry sealing material, and the flange plate is installed at the orifice; S3, a steel pipe is provided outside the drill bit of the drilling device, the angle of the drill pipe is adjusted in real time during drilling, and the drill bit and the steel pipe are ensured to advance cooperatively, and the drilling is carried out to the target depth, that is, the grouting hole is obtained, and the drilling device is taken out; S4, a plurality of cylindrical grouting sections are connected into a grouting pipe with a length not less than the depth of the grouting hole through connecting sleeves, the connecting sleeve comprises a support pipe with threaded sections at both ends, a sealing inner ring coaxially arranged in the support pipe, and a sealing outer ring coaxially arranged outside the support pipe, the grouting section is threadedly connected with the threaded section of the support pipe, the outer diameter of the sealing outer ring is greater than the diameter of the grouting hole, and the inner diameter of the sealing inner ring is slightly greater than the outer diameter of the grouting pipe; the grouting pipe is inserted into the steel pipe, the sealing outer ring and the steel pipe can be closely attached and smoothly slide during the insertion of the grouting pipe, when the grouting pipe is inserted to the bottom of the grouting hole, the steel pipe is pulled out, and the sealing outer ring is closely attached to the wall of the grouting hole; S5, the grouting pipe is inserted into the bottom of the grouting hole along the cavity composed of the grouting section and the sealing inner ring; S6, the grouting hole is sequentially reinforced by the backward grouting method.

2. The method according to claim 1, wherein, The angle measuring device comprises a base, a positioning pipe in the shape of C arranged on the base, an electronic digital display angle meter with magnetism placed on the base and closely attached to the positioning pipe, and three height-adjustable positioning legs hinged to the base; Arc-shaped sliding grooves are symmetrically arranged on the base at both ends of the positioning pipe; the drill pipe can be placed in the positioning pipe in parallel from the opening arranged in the axial direction of the positioning pipe, the middle part of the contact surface of the positioning pipe and the base is provided with a limiting unit, and both ends are provided with sliding units capable of sliding along the corresponding arc-shaped sliding grooves, the sliding units are symmetrically arranged with the limiting unit as the center, the limiting unit and the sliding unit have the same structure, and both comprise a vertical fixed bolt and a fixed nut arranged on the vertical fixed bolt, one end of the vertical fixed bolt is fixedly connected with the positioning pipe, the other end extends to below the base through the base, when the angle of the drill pipe is adjusted, the positioning pipe is rotated, the sliding unit moves along the arc-shaped sliding groove with the limiting unit as the center, when it is rotated to the target angle, the fixed nut is tightened to abut against the base, and then the positioning pipe can be fixed.

3. The method according to claim 2, wherein, The positioning pipe is further provided with a positioning unit capable of positioning the drill pipe placed in the positioning pipe, the positioning unit comprises a clamping nut welded on the positioning pipe and a clamping bolt threadedly connected with the clamping nut, and one end of the clamping bolt extends into the cavity of the positioning pipe.

4. The method according to claim 2, wherein, The base is circular, and the vertical fixed bolt in the limiting unit extends through the center of the base.

5. The method according to claim 2, wherein, Two fixed nuts are arranged on each vertical fixed bolt and are arranged on the upper and lower sides of the base.

6. The method according to claim 2, wherein, The bottom surface of the base is fixed with three pairs of circular arc-shaped limiting hoops, and the positioning legs are hinged with the base through the limiting hoops.

7. The method according to claim 2, wherein, The lower part of the positioning leg is provided with a tapered positioning foot.

8. The method according to claim 1, wherein, In step S4, the periphery of the slurry discharging section is uniformly provided with a plurality of slurry discharging ports.

9. The method according to claim 1, wherein, In step S6, the injection pressure control value is 0.5-1.0 MPa, and the injection is continued for a period of time after the injection pressure reaches the final pressure state, and then the injection is stopped.

10. The method according to claim 1, wherein, In step S6, the connecting sleeve is used as the domain position during the localized injection grouting.

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