A device and method for anchoring pile pressure excavation and rectification test

Abstract

The application discloses an anchor pile pressurizing soil digging and rectification test device and a test method, belongs to the soil digging and rectification technical field, and the device comprises a pressurizing assembly, a jack and a test block arranged from top to bottom, further comprises anchor piles and a soil digging pit, the anchor piles are four, and are punched on a site foundation; the pressurizing assembly comprises a lower pressurizing plate, an upper pressurizing plate and a reinforcing steel bar; the lower pressurizing plate is arranged in groups on the four jacks; the upper pressurizing plate is arranged in groups at the end of the lower pressurizing plate; the bottom of the reinforcing steel bar is embedded in the anchor pile, the top of the reinforcing steel bar extends out of the ground and sequentially penetrates the end of the lower pressurizing plate and the upper pressurizing plate, and a nut is arranged at the end of the reinforcing steel bar; the soil digging pit is longitudinally provided with a plurality of soil digging holes along the direction of the test block. The method comprises site pile forming, test block heaped loading, site soil digging, pressure test, data processing and result application. The structure given by the method in combination with the device can maximize the avoidance of the problems of sudden sinking, forced lowering and overall sinking in the rectification test and construction of buildings.

Description

Technical Field

[0001] This invention belongs to the field of soil removal and tilt correction technology, specifically relating to an anchor pile pressure soil removal and tilt correction test device and test method. Background Technology

[0002] Soil excavation for tilt correction is a common method for correcting the tilt of existing buildings. By constructing soil excavation holes, the stress area of ​​the foundation on one side of the building is reduced, causing the soil excavation holes to be damaged under pressure, thereby achieving the purpose of correcting the tilt of the building. During the tilt correction process, the soil excavation holes must not be damaged in a short period of time, which would cause the building to tilt suddenly, or the soil excavation holes must not be damaged locally, which would cause secondary damage to the building.

[0003] However, differences in building structure and geographical location lead to significant variations in foundation strength, deformation capacity, and stability. Therefore, corrective measures cannot completely replicate successfully completed projects. Meticulous measurement and monitoring are essential, with real-time data analysis used to continuously adjust various data indicators during the correction process to ensure the desired results are achieved.

[0004] In most existing technologies, the soil removal and correction construction methods involve on-site engineering technicians continuously adjusting the construction plan during construction by monitoring real-time data and changes in building cracks. They also observe whether the soil removal results in overall settlement or the expected settlement. Because this construction method lacks prior testing, many uncertainties arise during the correction process. The correction is highly random, difficult, and may even fail to achieve the expected correction effect. If the expected effect is not achieved, it will also increase the construction period.

[0005] Therefore, before determining the construction plan for excavation and correction of a building, an indoor geotechnical test model box will be used to simulate the construction site of excavation and correction. Based on the test process, various possible situations may occur during the excavation and correction construction, and the feasibility of the excavation and correction construction plan will be determined.

[0006] However, in the simulation tests using this type of indoor geotechnical test model box, both the excavation hole and the pressure are scaled down proportionally. But in the pressure test, the proportional scaling of the pressure and the actual pressure result differ significantly due to the non-linear effect of pressure loading. Furthermore, the soil used in the test is manually compacted, which differs greatly from the foundation conditions at the actual construction site. This results in a complete lack of similarity between the test intended to simulate the excavation and correction process and the actual construction site conditions, thus failing to provide effective construction parameters to guide the excavation and correction construction.

[0007] Based on the above background technology, the researchers proposed a test device and test method for anchor pile pressure excavation and tilt correction. Summary of the Invention

[0008] The purpose of this invention is to provide a test device for anchor pile pressure excavation and tilt correction, so as to solve the problem that the simulation test of the indoor geotechnical test model box does not have the same similarity as the actual construction site.

[0009] Another objective of this invention is to provide a test method for anchor pile pressure excavation and tilt correction, in order to solve the problem of lack of highly relevant test verification schemes before the construction of excavation and tilt correction of buildings.

[0010] To solve the above problems, the technical solution of the present invention is as follows: An anchor pile pressure excavation and tilt correction test device includes a pressure assembly, jacks, and a test block arranged from top to bottom. It also includes anchor piles and an excavation pit. There are four anchor piles driven into the ground. The pressure assembly includes a lower pressure plate, an upper pressure plate, and reinforcing bars. The lower pressure plates are arranged in groups on the four jacks. The upper pressure plates are arranged in groups at the ends of the lower pressure plates. The bottom of the reinforcing bars is embedded in the anchor piles, and the top of the reinforcing bars extends out of the ground and passes through the ends of the lower pressure plate and the upper pressure plate in sequence. The ends of the reinforcing bars are equipped with nuts. The excavation pit has several excavation holes longitudinally along the direction of the test block.

[0011] Furthermore, the diameter of the excavation hole is 13-15cm, and the center-to-center distance between adjacent excavation holes is 20cm-50cm.

[0012] Furthermore, a soil-removing platform is provided on the side of the soil-removing pit closest to the test block. The soil-removing platform is a step with a longitudinal width of 6cm-10cm and is 50cm-60cm above the ground. The soil-removing hole is located 5cm-8cm above the soil-removing platform.

[0013] Furthermore, the test block is composed of multiple concrete test blocks stacked in two layers, and the centroid of the combined section of the concrete test block coincides with the intersection of the diagonal lines of the center of the four anchor piles.

[0014] Furthermore, four displacement gauges were installed around the concrete test blocks stacked below the test blocks.

[0015] Furthermore, an endoscope was installed inside the excavation hole.

[0016] Furthermore, each anchor pile has four pre-embedded steel bars, each with a threaded top. Nuts are fastened to the threads, and a limiting plate is provided between the top of the upper pressure plate and the nut.

[0017] Furthermore, the test block consists of 10 concrete test blocks stacked in two layers. The lower layer has six blocks stacked close together, arranged in three rows horizontally and two columns vertically; the upper layer has four blocks stacked, arranged in two rows horizontally and two columns vertically, with a vertical spacing of 30cm-50cm.

[0018] A test method for correcting tilting of anchor piles by applying pressure and excavation. This method consists of the following steps: S1. On-site leveling and pile driving; Find a test site at the building site that needs to be corrected, level it first, and then construct an anchor pile; at the same time, pre-embed four steel bars, and thread the top of the steel bars before pre-embedding to form steel bar threads. After the final construction and curing are completed, the steel bars will be 4-6m above the ground. S2, Test block loading; S2.1 Test block stacking; The test block is made by stacking two layers of concrete test blocks; The bottom layer consists of six blocks arranged in two horizontal rows and three vertical columns, forming a cuboid. Four displacement gauges are installed around the top layer of this cuboid. The distance between the edge of the bottom layer test block and the longitudinal distance of the excavation pit is 50cm-80cm. The top layer consists of four pieces, which are closely connected horizontally and spaced 30cm-50cm apart vertically. The centroid of the combined test block section coincides with the intersection of the diagonals of the four anchor piles' cores; S2.2 Pressurization component installation; Four jacks were placed at the center of the four test blocks on the top layer; Two lower pressure plates are horizontally installed on the jacks in the group, and then two upper pressure plates are vertically installed on the lower pressure plates; the pre-embedded steel bars all pass through the lower pressure plates and upper pressure plates, and a limiting plate is added to the threaded steel bar, and then the nut is tightened on the threaded steel bar. S3, excavation of soil on site; A soil excavation pit was dug on the front side of the longitudinal direction of the test block. A soil excavation platform was set on the side of the soil excavation pit close to the test block. Several soil excavation holes were drilled on the soil excavation platform along the longitudinal direction. The changes in cracks in the soil excavation holes were observed and photographed by moving an endoscope. The distance between the edge of the excavation pit and the nearest test block is 50cm-80cm. After excavation, the longitudinal width of the excavation platform is 6cm-10cm, and the excavation platform is about 50cm from the ground. The diameter of the excavation holes is usually 13-15cm, and the center-to-center spacing of the excavation holes is 20cm-50cm. S4. Pressure test; S4.1 Once a day, gradually increasing pressure; Ensure that the pressure values ​​of the four jacks are consistent, and apply pressure once a day. The pressure values ​​should be increased in the following order: 20t, 40t, 60t, 80t, 100t, 120t, 140t, 160t, 180t, 200t, 220t, 240t, and 260t. Continue to increase the pressure gradually until the excavation hole is completely destroyed. During the pressure application period, the following data collection steps should be performed regularly every day. S4.2 Settlement monitoring; Read the readings of the four displacement gauges three times a day, and at the same time measure the horizontal displacement and settlement at the observation points of the four displacement gauges with a total station as a verification of the displacement gauge data, and record the settlement data after verification. S4.3 Measurement of vertical diameter of excavation hole and acquisition of images of cracks around the hole; Simultaneously with settlement monitoring, the vertical diameter of each excavation hole was measured, and images of cracks in the surrounding soil and between soil strips were acquired to observe crack development. S4.4 Endoscopic image acquisition; While measuring the vertical diameter of the excavation holes, an endoscope was inserted into each excavation hole to collect data on the deformation and crack development direction inside the excavation hole, and images were collected to record these characteristics in order to infer the stress and displacement development direction of the soil. S5. Data processing and results application; The settlement test ended when the excavation hole was completely destroyed. The data obtained were: the failure pressure value of the excavation hole in S4.1; the monitoring data of horizontal displacement and settlement of the test block under different pressure values ​​in S4.2; the monitoring data of vertical hole diameter deformation, cracks in the soil around the hole and the soil strips between the holes in S4.3; and the monitoring data of internal deformation and cracks of the excavation hole in S4.4. A pressure settlement curve was plotted based on the above monitoring data. Establish the correlation between the pressure settlement curve and the changes in the state of the excavation hole, and determine the adjustment scheme of the excavation hole at the test site based on the changing trend of the pressure settlement curve.

[0019] Furthermore, the specific correlation between the S5 pressure settlement curves and the adjustment schemes for the excavation holes is as follows: S5.1 If the trend of change in a certain pressure loading range is too large, it indicates that a sudden settlement has occurred. The following measures can be taken during the excavation and correction construction to avoid this: Based on the original excavation hole used in the experiment, one or more combinations of the following measures were adopted; Increase the spacing between adjacent excavation holes; Reduce the diameter of the excavation hole; Increase the distance between the excavation hole and the ground appropriately; Appropriately reduce the longitudinal length of the excavation hole; S5.2 If a pressure increase occurs within a certain pressure loading range while settlement is minimal, it indicates a tendency for forced settlement. The following measures can be taken during soil removal and correction construction to avoid this: Based on the original excavation hole used in the experiment, one or more combinations of the following measures were adopted; Reduce the distance between adjacent excavation holes; Increase the diameter of the excavation hole; Appropriately reduce the distance between the excavation hole and the ground; Increase the longitudinal length of the excavation hole appropriately; S5.3 If a pressure loading zone experiences high pressure but fails to completely destroy the excavation hole or the degree of destruction is insufficient, it indicates an overall subsidence trend. The following measures can be taken during the excavation and correction construction to avoid this: Based on the original excavation hole in the experiment, the longitudinal length of the excavation hole was increased; When construction is carried out after the completion of the S5.4 test, the construction curve drawn based on the real-time monitoring data during the soil removal and tilt correction construction is compared with the pressure settlement curve drawn based on the monitoring data during the test. When some areas show the same or similar curve change trend, the corresponding adjustment scheme for the soil removal hole in S5.1-S5.3 is adopted to adjust the soil removal and tilt correction before proceeding with the soil removal and tilt correction.

[0020] The beneficial effects of this invention are as follows: (1) The device of the present invention selects the construction site as the test site for the first time. It uses the pressure component, jack, test block and anchor pile to provide reaction force through the anchor pile to carry out the soil excavation test on site. Through the construction of the soil excavation pit and soil excavation hole, the settlement and displacement of the concrete test block are measured with the help of the displacement gauge. The endoscope is introduced to observe the internal morphology of the soil excavation hole and the development and change process of cracks. With the help of these on-site monitoring test data, the on-site construction can be better guided.

[0021] (2) The method of this invention, combined with the structure provided by the device, uses data obtained from on-site monitoring to determine the size and number of soil holes through the relationship between vertical pressure and settlement changes, and between vertical pressure and soil hole failure. The influence of soil compression and displacement on settlement can be seen through the changes in the vertical diameter of the soil holes, the readings of the displacement gauges, and their differences. Since sudden settlement is the most undesirable phenomenon in soil excavation and tilt correction, the relationship between vertical pressure and settlement changes, and between vertical pressure and soil hole failure can be obtained through experiments. Therefore, based on this experiment, the danger of sudden settlement during building tilt correction can be avoided to the greatest extent. Corresponding construction guidance and adjustment schemes are also given for the possible forced settlement trend and overall subsidence problem in soil excavation construction.

[0022] (3) The pressure settlement curve plotted in the soil removal and correction test of this invention can reflect the settlement state of the soil and test block during the soil removal and correction test. This means that the pressure settlement curve plotted has practical guiding significance in the demonstration of the soil removal and correction construction scheme, and can reflect the settlement state of the soil and building during the soil removal and correction construction. Moreover, different pressure settlement curve trends correspond to different construction schemes and measures. The combination of the two can not only predict various phenomena that may occur during the soil removal and correction construction in advance, but also use corresponding measures to avoid problems such as sudden settlement, forced settlement and overall subsidence during the soil removal and correction construction, and finally achieve the best soil removal and correction effect. Attached Figure Description

[0023] Figure 1 A schematic diagram of a test device for adjusting the tilt of anchor piles by applying pressure and excavating soil. Figure 2 A schematic diagram of the structure of a test device for adjusting the tilt of anchor piles by applying pressure and excavating soil from a second perspective; Figure 3 A third-view structural schematic diagram of an anchor pile pressure excavation and tilt correction test device; Figure 4 This is a schematic diagram of the test block stacking in Example 1; Figure 5 for Figure 4 Side view; Figure 6 for Figure 4 Top view; The attached diagram is labeled as follows: 1-Anchor pile; 2-Pressure assembly; 21-Lower pressure plate; 22-Upper pressure plate; 23-Limiting plate; 24-Reinforcing bar; 25-Reinforcing bar thread; 26-Nut; 3-Test block; 4-Jack; 5-Soil excavation pit; 51-Soil excavation hole; 52-Soil excavation platform; 6-Displacement gauge; 7-Endoscope. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Therefore, the following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0026] Example 1 like Figure 1-6 As shown, an anchor pile pressure excavation soil correction test device includes an excavation pit 4 excavated on site, an anchor pile 1, a pressure component 2, a test block 3, and a jack 4 set on one side of the excavation pit 4.

[0027] Four anchor piles (anchor pile 1) are driven, each anchor pile 1 having four pre-embedded steel bars (24mm). The transverse and longitudinal spacing between the centers of anchor piles 1 are 6m and 1.6m, respectively; for ease of description, ... Figure 1 Based on this, length is described as horizontal, width as vertical, and depth as vertical, and the following descriptions are consistent. The pile diameter is 60cm; the reinforcing bar 24 in anchor pile 1 extends 4-6m above the ground. The pile diameter, pile length, pile spacing, and length of the embedded reinforcing bars can be calculated and adjusted based on the size of the concrete test blocks used on site, geotechnical mechanics parameters, etc.

[0028] A soil-excavation platform 52 is provided on one side of the excavation pit 5. The excavation platform 52 is a step with a longitudinal width of 6cm. Several soil-excavation holes 51 are set about 5cm away from the top of the excavation platform 52. The diameter of the soil-excavation holes 51 is usually 13-15cm, and the center-to-center spacing of the soil-excavation holes is 20cm-50cm. The changes in cracks in the soil-excavation holes 51 can be observed and photographed by a movable built-in endoscope 7.

[0029] The pressurizing assembly 2 includes a set of lower pressurizing plates 21 and upper pressurizing plates 22 located at both ends of the lower pressurizing plates 21. Four limiting plates 23 are provided above the upper pressurizing plates 22. The steel bars 24 pre-embedded in the anchor pile 1 pass through the ends of the lower pressurizing plates 21, the ends of the upper pressurizing plates 22, and the limiting plates 23. The steel bars 24 above the limiting plates 23 are provided with steel bar threads 25, and the steel bar threads 25 are provided with nuts 26.

[0030] Four displacement gauges 6 are installed around the test block 3. The longitudinal distance between the edge of the test block 3 and the excavation pit 5 is 50cm.

[0031] Jack 4 is positioned between test block 3 and lower pressure plate 21.

[0032] The test method for the above anchor pile pressure excavation and tilt correction device is divided into the following steps: S1. On-site leveling and pile formation; Find a test site at the site of the building that needs to be corrected, level the test site, and select an appropriate pile driving construction process based on the site's foundation soil conditions to drive the piles.

[0033] like Figure 1-3 As shown, four anchor piles 1 are constructed, with a pile diameter of 60cm, a horizontal center-to-center spacing of 6m, and a longitudinal center-to-center spacing of 2m. First, the tied steel cage is placed, and four Φ32 steel bars 24 are pre-embedded, so that the steel bars 24 are 4-6m above the ground vertically. Then, concrete pouring is carried out. After construction and curing are completed, the process proceeds to S2.

[0034] Before pre-embedding, the top of the reinforcing bar 24 is threaded to form the reinforcing bar thread 25.

[0035] The pile diameter, pile length, pile spacing, and length of embedded steel bars can all be calculated and adjusted according to the actual site conditions.

[0036] S2, Test block loading; S2.1 Test block stacking; Test block 3 consists of concrete test blocks with length, width, and height of 2m, 1m, and 1m respectively, stacked in two layers.

[0037] Specific stacking methods are as follows: Figure 4-6 As shown: The bottom layer consists of six blocks arranged in two horizontal rows and three vertical columns, forming a cuboid. Four displacement gauges 6 are installed around the top layer of the cuboid. The edge of the bottom test block 3 is 50cm away from the longitudinal distance of the excavation pit 5. The top layer consists of four pieces, which are closely connected horizontally and spaced 30cm apart vertically.

[0038] To ensure that the intersection of the diagonals of the four pile cores coincides with the centroid of the composite section of the concrete test block (e.g., Figure 6 (As shown by the auxiliary dashed line).

[0039] S2.2 Pressurization component installation; Four jacks 4 are placed in the center of the four test blocks 3 on the top layer.

[0040] Two lower pressure plates 21 are horizontally installed on the set of jacks 4, and then two upper pressure plates 22 are vertically installed on the lower pressure plates 21. The pre-embedded steel bars 24 all pass through the lower pressure plates 21 and the upper pressure plates 22, and a limiting plate 23 is added to the threaded steel bar 25. Then, the nut 26 is tightened on the threaded steel bar 25.

[0041] Both the lower pressure plate 21 and the upper pressure plate 22 are I-beams, and each end is provided with threaded holes that are compatible with the four pre-embedded steel bars 24.

[0042] The limiting plate 23 is a 3cm thick steel plate, and four 32mm diameter threaded holes are pre-drilled. The hole diameter is determined according to the diameter of the pre-embedded steel bars, and the hole spacing is determined according to the spacing of the four pre-embedded steel bars.

[0043] S3, excavation of soil on site; A soil excavation pit 5 is excavated on one side of test block 3. A soil excavation platform 52 is provided on the side of the soil excavation pit 5 closest to test block 3. Several soil excavation holes 51 are drilled longitudinally on the soil excavation platform 52. The changes in cracks in the soil excavation holes 51 are observed and photographed by an endoscope 7.

[0044] The edge of the excavation pit 5 is 50cm away from the nearest test block 3. After excavation, measurements are taken to ensure that the excavation pit 5 is 5m long, 4m wide, and 1.5m deep.

[0045] The excavation platform 52 is a 6cm wide step to facilitate excavation work. The excavation platform 52 is about 50cm above the ground.

[0046] The diameter of the excavation hole 51 is usually 13-15cm, and the center-to-center spacing of the excavation holes is 20cm-50cm.

[0047] S4. Pressure test; S4.1 Once a day, gradually increasing pressure; Ensure that the pressure values ​​of the four jacks are consistent, and apply pressure once a day. The pressure values ​​should be increased in the following order: 20t, 40t, 60t, 80t, 100t, 120t, 140t, 160t, 180t, 200t, 220t, 240t, and 260t. Continue to increase the pressure gradually until the excavation hole is completely destroyed. During the pressure application period, the following data collection steps should be performed regularly every day.

[0048] S4.2 Settlement monitoring; The readings of the four displacement gauges 6 were taken three times a day. At the same time, the horizontal displacement and settlement of the four observation points of the displacement gauges 6 were measured with a total station as a verification of the displacement gauge data. The settlement data after verification was recorded.

[0049] S4.3 Measurement of vertical diameter of excavation hole and acquisition of images of cracks around the hole; Simultaneously with settlement monitoring, the vertical diameter of each excavation hole 51 was measured, and images of cracks in the surrounding soil and between soil strips were acquired to observe crack development.

[0050] S4.4 Endoscopic image acquisition; While measuring the vertical diameter of the excavation holes 51, an endoscope is inserted into each excavation hole 51 to collect data on the deformation and crack development direction inside the excavation hole 51, and images are collected to record these features in order to infer the stress and displacement development direction of the soil.

[0051] In the above tests, the direction of soil stress and displacement development was mainly determined based on the direction of crack change in the excavation hole 51. If the displacement direction of the soil in the excavation hole 51 is mainly in the direction of the hole (longitudinal), it indicates that the excavation and correction has resulted in overall settlement. If the displacement direction of the soil inside the excavation hole 51 is perpendicular to the direction of the excavation hole 51 (vertical), it indicates that the destruction of the excavation hole 51 has achieved the expected effect of excavation and correction.

[0052] S5. Data processing and results application; Based on the destructive pressure value of the excavation hole obtained in S4.1, the horizontal displacement and settlement of test block 3 under different pressure values ​​obtained in S4.2-S4.5, the external deformation and cracks around the excavation hole, and the internal deformation and cracks of the excavation hole, the excavation site's excavation and tilt correction construction plan is determined and given.

[0053] In this embodiment, during field testing: When the load reached 20t, settlement began to occur on the side near the excavation pit 5, with a settlement of 8mm. No cracks or obvious damage were observed in the soil between the excavation holes 51, indicating that the settlement was caused by soil displacement and displacement perpendicular to the direction of the excavation holes 51.

[0054] When the load reached 60t, cracks began to appear in the excavation hole 51. The cracks were vertical and slightly biased towards the excavation pit 5, indicating that the soil had a small displacement towards the excavation pit 5. Vertical cracks also appeared in the soil strips between the excavation holes 51.

[0055] When the load reached 100t, diagonal cracks appeared around the vertical cracks in the previously excavated hole 51, and the settlement on the side near the excavated hole 51 reached 2.1cm. Cracks also appeared around the vertical cracks in the soil strips between the excavated holes 51.

[0056] When the load reached 140t, the cracks in the excavation hole 51 and the cracks in the soil strips between the excavation holes 51 increased in size, and the settlement on the side near the excavation pit developed to 4.3cm.

[0057] When the load reached 180t, the side closest to the excavation pit 5 settled by 6.9cm, and the vertical cracks in the previous excavation hole 51 were clearly damaged.

[0058] When the load reached 220t, the settlement on the side near the excavation pit 5 was 9.8cm, and the previous cracks in the soil strips inside the excavation pit 5 and between the excavation holes 51 were no longer visible.

[0059] When the load reached 260t, the soil between the excavation holes 51 was completely destroyed, and the settlement on the side closer to the excavation pit 5 reached 14.2cm. The settlement on the side away from the excavation pit 5 was 3mm, which can be ignored. The test is now complete.

[0060] The test results show that the settling rate tends to increase after loading, but it is within a controllable range.

[0061] The settlement test ended when the excavation hole 51 was completely destroyed. The data obtained were: the destruction pressure value of the excavation hole 51 in S4.1; the monitoring data of horizontal displacement and settlement of the test block 3 under different pressure values ​​in S4.2; the monitoring data of vertical diameter deformation of the excavation hole 51, cracks in the soil around the hole and the soil strips between the holes in S4.3; and the monitoring data of internal deformation and cracks of the excavation hole in S4.4.

[0062] The pressure-settlement curve was plotted based on the above monitoring data. The correlation between pressure, settlement, and the state changes of excavation hole 51 was established, and the adjustment scheme of excavation hole 51 at the test site was determined based on the changing trend of the pressure-settlement curve.

[0063] The specific relationship between the pressure settlement curve and the adjustment scheme of excavation hole 51 is as follows: S5.1 If the trend of change in a certain pressure loading range is too large, it indicates that a sudden settlement has occurred. The following measures can be taken during the excavation and correction construction to avoid this: Based on the original excavation hole 51 in the experiment, one or more combinations of the following measures were adopted.

[0064] Increase the spacing between adjacent excavation holes 51; Reduce the diameter of the excavation hole 51; Increase the distance between the excavation hole 51 and the ground surface appropriately; The longitudinal length of the excavation hole 51 should be appropriately reduced.

[0065] S5.2 If a pressure increase occurs within a certain pressure loading range while settlement is minimal, it indicates a tendency for forced settlement. The following measures can be taken during soil removal and correction construction to avoid this: Based on the original excavation hole 51 in the experiment, one or more combinations of the following measures were adopted.

[0066] Reduce the spacing between adjacent excavation holes 51; Increase the diameter of the excavation hole 51; Appropriately reduce the distance between the excavation hole 51 and the ground; Increase the longitudinal length of the excavation hole 51 appropriately.

[0067] S5.3 If a pressure loading zone experiences high pressure but fails to completely destroy the excavation hole or the degree of destruction is insufficient, it indicates an overall subsidence trend. The following measures can be taken during the excavation and correction construction to avoid this: Based on the original excavation hole 51 in the experiment, the longitudinal length of the excavation hole 51 was increased.

[0068] When construction is carried out after the completion of the S5.4 test, the construction curve drawn based on the real-time monitoring data during the soil removal and tilt correction construction is compared with the pressure settlement curve drawn based on the monitoring data during the test. When certain areas show the same or similar curve change trends, the corresponding adjustment schemes for soil removal hole 51 in S5.1-S5.3 are adopted to adjust the soil removal hole 51 to avoid sudden settlement, forced settlement and overall subsidence problems during construction.

Claims

1. A test method for correcting tilting of anchor piles by applying pressure and excavating soil, characterized in that: This method consists of the following steps: S1. On-site leveling and pile driving; Find a test site at the site of the building that needs to be corrected, level it first, and then construct 4 anchor piles (1); at the same time, pre-embed four steel bars (24). Before pre-embedding, thread the top of the steel bars (24) to form steel bar thread (25). After the final construction and curing, the steel bars (24) are 4-6m above the ground. S2, Test block loading; S2.1 Test block stacking; Test block (3) is made by stacking two layers of concrete test blocks; The bottom layer consists of six blocks, arranged in two horizontal rows and three vertical columns. The six blocks are closely connected to form a cuboid. Four displacement gauges (6) are set around the top layer of the cuboid. The distance between the edge of the bottom test block (3) and the longitudinal distance between it and the excavation pit (5) is 50cm-80cm. The top layer consists of four pieces, which are closely connected horizontally and spaced 30cm-50cm apart vertically. The centroid of the combined test block (3) section coincides with the diagonal intersection of the centroids of the four anchor piles (1); S2.2 Pressurization component installation; Four jacks (4) are placed in the center of the four test blocks (3) on the top layer respectively; Two lower pressure plates (21) are horizontally installed on the jacks (4) in the group, and then two upper pressure plates (22) are vertically installed on the lower pressure plates (21); the pre-embedded steel bars (24) all pass through the lower pressure plates (21) and the upper pressure plates (22), and a limiting plate (23) is added to the threaded steel bar (25) that passes through, and then the nut (26) is tightened on the threaded steel bar (25); S3, On-site excavation; A soil excavation pit (5) is excavated on the front side of the longitudinal direction of the test block (3). A soil excavation platform (52) is provided on the side of the soil excavation pit (5) close to the test block (3). Several soil excavation holes (51) are drilled on the soil excavation platform (52) along the longitudinal direction. The changes in cracks in the soil excavation holes (51) are observed and photographed by moving an endoscope (7). The edge of the excavation pit (5) is 50cm-80cm away from the nearest test block (3). After excavation, the longitudinal width of the step of the excavation platform (52) is 6cm-10cm, and the excavation platform (52) is about 50cm away from the ground. The diameter of the excavation hole (51) is usually 13-15cm, and the center-to-center distance of the excavation hole is 20cm-50cm; S4. Pressure test; S4.1 Once a day, gradually increasing pressure; Ensure that the pressure values ​​of the four jacks (4) are consistent, and pressurize once a day. The pressure values ​​are 20t, 40t, 60t, 80t, 100t, 120t, 140t, 160t, 180t, 200t, 220t, 240t, and 260t in ascending order. Pressurize step by step until the soil hole is completely destroyed. During the pressurization period, the following data collection steps are performed regularly every day. S4.2 Settlement monitoring; Read the readings of the four displacement gauges (6) three times a day, and at the same time measure the horizontal displacement and settlement of the observation points at the four displacement gauges (6) with a total station as a verification of the displacement gauge data, and record the settlement data after verification. S4.3 Measurement of vertical diameter of excavation hole and acquisition of images of cracks around the hole; Simultaneously with settlement monitoring, the vertical diameter of each excavation hole (51) was measured, and images of cracks in the surrounding soil and between soil strips were collected to observe the development of cracks. S4.4 Endoscopic image acquisition; While measuring the vertical diameter of the excavation hole (51), an endoscope was inserted into each excavation hole (51) to collect the deformation and crack development direction inside the excavation hole (51) and to collect images to record these features in order to infer the stress and displacement development direction of the soil. S5. Data processing and results application; The settlement test ended when the excavation hole (51) was completely destroyed. The destruction pressure value of the excavation hole (51) was obtained through S4.1; and the monitoring data of the horizontal displacement and settlement of the test block (3) under different pressure values ​​were obtained through S4.

2. The vertical diameter deformation of the excavation hole (51), the crack monitoring data of the soil around the hole and the soil strip between the holes obtained in S4.3; Data on deformation and crack monitoring inside the excavation hole obtained in S4.4; A pressure settlement curve was plotted based on the above monitoring data. Establish the correlation between the pressure settlement curve and the state change of the excavation hole (51), and determine the adjustment scheme of the excavation hole (51) at the test site based on the changing trend of the pressure settlement curve.

2. The anchor pile pressure excavation and tilt correction test method as described in claim 1, characterized in that: The specific relationship between the pressure settlement curve in S5 and the adjustment scheme of the excavation hole (51) is as follows: S5.1 If the trend of change in a certain pressure loading range is too large, it indicates that a sudden settlement has occurred. The following measures can be taken during the excavation and correction construction to avoid this: Based on the original excavation hole (51) of the experiment, one or more combinations of the following measures were adopted; Increase the spacing between adjacent excavation holes (51); Reduce the diameter of the excavation hole (51); Increase the distance between the excavation hole (51) and the ground appropriately; Appropriately reduce the longitudinal length of the excavation hole (51); S5.2 If a pressure increase occurs within a certain pressure loading range while settlement is minimal, it indicates a tendency for forced settlement. The following measures can be taken during soil removal and correction construction to avoid this: Reduce the spacing between adjacent excavation holes (51); Increase the diameter of the excavation hole (51); Appropriately reduce the distance between the excavation hole (51) and the ground; Appropriately increase the longitudinal length of the excavation hole (51); S5.3 If a pressure loading zone experiences high pressure but fails to completely destroy the excavation hole or the degree of destruction is insufficient, it indicates an overall subsidence trend. The following measures can be taken during the excavation and correction construction to avoid this: Based on the original excavation hole (51) in the experiment, the longitudinal length of the excavation hole (51) was increased; When construction is carried out after the completion of the S5.4 test, the construction curve drawn based on the real-time monitoring data during the soil removal and tilt correction construction is compared with the pressure settlement curve drawn based on the monitoring data during the test. When some areas show the same or similar curve change trend, the corresponding adjustment scheme for the soil removal hole (51) in S5.1-S5.3 is adopted for adjustment.

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