A method for reinforcing the engineering characteristics of a slope under the condition of a weak layer of a soil-rock interface
By combining multiple sets of comparative experiments and sensor monitoring with computer analysis, the inaccuracy of reinforcement effect and deformation evaluation of weak soil-rock interface layers has been solved, enabling accurate detection and stability assessment of slope engineering.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-07-25
- Publication Date
- 2026-04-14
AI Technical Summary
Existing methods for slope reinforcement under weak soil-rock interface conditions rely on limited testing experiments, making it difficult to accurately assess reinforcement effectiveness and resulting in inaccurate deformation evaluation.
Multiple sets of comparative experiments were used to detect the reinforcement effect of the weak layer at the soil-rock interface. Slope deformation was monitored by sensors and displacement sensors. Combined with computer analysis, a drainage system and reinforcement structure were set up, and pull-out and bearing capacity tests were conducted. Deformation was evaluated using Fourier series expressions.
It enables precise detection of the reinforcement effect of the weak layer at the soil-rock interface and accurate evaluation of deformation, improving the accuracy of the experiment and the diversity of detection, and ensuring the stability of slope engineering.
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Figure CN116927217B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of slope engineering, and in particular to a method for reinforcing the engineering characteristics of slopes under conditions of weak soil-rock interface. Background Technology
[0002] Weak layers at the soil-rock interface on slopes are prone to landslides and collapses. Weak rock layers refer to bedrock with exceptionally low strength and elastic modulus. Some of these rocks are still relatively hard, but become weak due to weathering or dense fissures and joints; others are simply weak due to their inherent rock type. The mineral components of weak rock layers are mainly clay minerals such as kaolinite, illite, and montmorillonite, all of which belong to layered or layer-chain silicates. Two structural unit types form the basis of their crystal structure: silicon-oxygen tetrahedra and silicon-oxygen octahedra. With the continuous development and improvement of methods such as X-ray diffraction and thermal analysis, it is now possible to accurately determine the type and content of mineral components in weak rock layers. However, existing methods for reinforcing slopes under weak soil-rock interface conditions rely on relatively simple testing methods for reinforcement effectiveness, lacking multiple comparative experiments. Consequently, it is difficult to accurately assess the reinforcement effect at testing points under these conditions. Furthermore, the evaluation of deformation in weak soil-rock interface layers is inaccurate.
[0003] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:
[0004] (1) The existing methods for reinforcing slopes under the condition of weak soil-rock interface have relatively simple testing methods for the reinforcement effect, and no multiple sets of comparative experiments have been set up. Therefore, it is impossible to accurately judge the reinforcement effect of the test points of the slope under the condition of weak soil-rock interface.
[0005] (2) The evaluation of the deformation of the weak layer at the soil-rock interface of the slope is inaccurate. Summary of the Invention
[0006] In view of this, the present invention addresses the deficiencies of the existing technology, and its main objective is to provide a method for reinforcing slope engineering characteristics under the condition of a weak soil-rock interface layer, which can accurately determine the reinforcement effect of slope engineering detection points under the condition of a weak soil-rock interface layer.
[0007] To achieve the above objectives, the present invention adopts the following technical solution:
[0008] A method for reinforcing the engineering properties of slopes under weak soil-rock interface conditions includes the following steps:
[0009] (1) The weak layer area of the soil-rock interface on the slope is detected by the geological detection equipment; the reinforcement effect of the slope engineering detection point under the condition of the weak layer of the soil-rock interface is detected; and the deformation of the weak layer of the soil-rock interface on the slope is evaluated; the specific position of each drainage board is determined by the small bamboo stick in the weak layer area of the soil-rock interface on the slope, the insertion machine is centered and leveled, and the drainage board is placed on the drill bit.
[0010] (2) Start the pile driver to hammer the drill rod, send the drainage board into the design depth of the weak layer of the soil-rock interface of the slope, lift the drill rod up, cut the drainage board on the ground and leave a certain length of spare length, fill sand around the drainage board to complete the construction of this drainage board; drain the weak layer of the soil-rock interface of the slope.
[0011] (3) Set up vertical drainage wells in the weak layer of soil-rock interface, which are made of medium or coarse sand. Drive steel pipes with embedded pile shoes at the lower end into the soil, and then pour sand from the upper end, compact in layers, and arch the steel pipes upward until the pile hole is filled with sand to form a sand well; drive wooden piles into cohesive soil first, and after pulling out the piles, fill the hole with sand and compact it to reinforce it.
[0012] Preferably, the method for detecting the reinforcement effect of slope engineering testing points under the condition of weak soil-rock interface is as follows:
[0013] (1) Sensor installation:
[0014] Five detection points were selected in the weak soil-rock interface layer of the slope with the same area and weight ratio. Six pressure sensors were installed at equal distances on the upper surface of each detection point, and six displacement sensors were installed at equal distances on the lower surface of each detection point. Both pressure sensors and displacement sensors were connected to an external computer.
[0015] (2) Installation of detection points:
[0016] The detection points of the weak soil-rock interface layer on the slope were divided into six parts. Then, three weak soil-rock interface layers of different depths and three weak soil-rock interface layers of the same depth were selected. The detection points of the six parts of the weak soil-rock interface layer were placed into the six weak soil-rock interface layers in sequence. After placement, the detection points in the weak soil-rock interface layer were backfilled with soil. After backfilling, the dry density of the backfilled soil was made consistent with the dry density of the surrounding soil.
[0017] (3) Simulated rainfall:
[0018] Rainfall devices were installed above the weak soil-rock interface layers at three different depths of slopes to ensure that the rainfall amount and duration were the same. Then, rainfall devices were installed above the weak soil-rock interface layers at three slopes of the same depth, but with different rainfall amounts.
[0019] (4) Pull-out test, load-bearing test and experimental analysis:
[0020] Pull rings are installed at the four corners of each detection point, and one end of each of the four traction ropes is fixed to the four pull rings. Then, the other end of each of the four traction ropes is connected to a tension gauge, which is then connected to an external computer.
[0021] After rainfall for one hour on the weak layer of soil-rock interface on each slope, pull the tension gauge on each traction rope to apply pull load to the detection point until the backfill soil heaves and breaks. At this time, the pressure sensor, displacement sensor and tension gauge will transmit data to the external computer during the pulling process, and the computer will record the data.
[0022] The detection points were reset and a rain-driving device was installed. One hour after the rain, a pressing device was set up above each detection point and operated until the detection point was completely submerged in the soil. During the pressing process, an external computer recorded the values of the pressure sensor and the displacement sensor.
[0023] After the pull-out and bearing capacity tests are completed, the data from the pressure sensor, displacement sensor, and tension gauge are recorded by the computer. By analyzing the data on the pull-out performance and bearing capacity of the weak soil-rock interface foundation of the slope, and by combining the area and weight of the test points with the actual area and weight of the test points of the weak soil-rock interface of the slope, the pull-out bearing capacity data value of the actual weak soil-rock interface test points of the slope can be obtained.
[0024] Preferably, after the pressure sensor and displacement sensor are installed, a layer of PVC film is covered on both the upper and lower surfaces of the detection point of the weak layer at the soil-rock interface of the slope.
[0025] Preferably, when backfilling the detection points in the weak layer of the soil-rock interface of the slope, the soil is backfilled in three stages, and the backfilled soil is compacted after each backfilling.
[0026] Preferably, the rain-spraying device uses nozzles for spraying, with 3 to 6 nozzles above each detection point. Rainwater is pumped out, acidic substances are added to the rainwater, and a fan blows the rainwater during the rainfall to more realistically simulate rainy weather.
[0027] Preferably, the pressing device uses a hydraulic cylinder to drive the pressing plate to press the detection point.
[0028] Preferably, after the experimental analysis is completed, the results are recorded in a book for easy reference in the future.
[0029] Preferably, the method for evaluating the deformation of the weak layer at the soil-rock interface of the slope is as follows:
[0030] 1) Construct a stratigraphic database and store the data of the weak layer of the soil-rock interface on the slope into the stratigraphic database; obtain the settlement data of the weak layer of the soil-rock interface on the slope, the settlement data including the settlement amount and the circumferential angle; fit the settlement data through a Fourier series expression to obtain the fitted harmonic amplitude and phase angle.
[0031] 2) Obtain the radial deformation value to be evaluated of the weak layer at the soil-rock interface of the slope based on the harmonic amplitude, the phase angle, and the preset radial deformation calculation formula; obtain and display the evaluation result based on the radial deformation value to be evaluated of the weak layer at the soil-rock interface of the slope and the preset rules;
[0032] The preset formula for calculating radial deformation is obtained based on simulation experiments using a full finite element model, as follows:
[0033]
[0034] Where y is the radial deformation value, n is the harmonic number, and θ is the circumferential angle. It is the phase angle of the nth harmonic when they are superimposed. kn is a function of the amplitude un of the nth harmonic settling.
[0035] Preferably, the Fourier series expression is:
[0036]
[0037] Where u is the settlement, θ is the circular angle, 0≤θ≤2π, u0 is the overall uniform settlement of the weak layer at the soil-rock interface of the slope, un is the amplitude of the nth harmonic settlement, and n is the harmonic number. Let n be the phase angle of the nth harmonic during superposition.
[0038] Preferably, obtaining the radial deformation value to be evaluated of the weak layer at the soil-rock interface of the slope based on the harmonic amplitude, the phase angle, and a preset radial deformation calculation formula includes:
[0039] Based on different orders, the calculation formula for the corresponding order is obtained from the radial deformation calculation formula;
[0040] The radial deformation value for the corresponding order is obtained by using the calculation formula for the corresponding order, the harmonic amplitude value, and the phase angle.
[0041] By superimposing the radial deformation values at different orders, the radial deformation curve of the weak layer at the soil-rock interface of the slope after settlement is obtained.
[0042] The radial deformation value to be evaluated is obtained based on the radial deformation curve.
[0043] The process of obtaining and displaying the evaluation results based on the radial deformation value of the weak layer at the soil-rock interface of the slope and preset rules includes:
[0044] If the radial deformation value to be evaluated is less than the preset value, the evaluation result is that the deformation of the weak layer of the soil-rock interface on the slope is not excessive, indicating that the weak layer of the soil-rock interface on the slope is qualified; otherwise, the evaluation result is that the deformation of the weak layer of the soil-rock interface on the slope exceeds the standard, indicating that the weak layer of the soil-rock interface on the slope is unqualified.
[0045] The process of acquiring settlement data of the weak layer at the soil-rock interface of the slope includes: setting vertical displacement observation points on the edge of the weak layer at the soil-rock interface of the slope, setting horizontal displacement side stakes at the locations of the vertical displacement observation points, and collecting settlement data at the locations of the horizontal displacement side stakes using a level.
[0046] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, as can be seen from the above technical solution:
[0047] This invention provides a method for testing the reinforcement effect of slope engineering test points under conditions of weak soil-rock interface. It sets up weak soil-rock interface layers at different depths, with the same rainfall, and weak soil-rock interface layers at the same depth, with different rainfall. Pull-out and bearing capacity tests are then conducted on the test points at the weak soil-rock interface. This allows for multiple sets of comparative experiments, ensuring the accuracy of the tests and overcoming the limitations of traditional experimental results. This enables personnel to better assess the performance of the test points at the weak soil-rock interface. Simultaneously, the method for evaluating the deformation of the weak soil-rock interface layer can accurately assess its deformation. Attached Figure Description
[0048] Figure 1 This is a flowchart of a preferred embodiment of the present invention for a method to reinforce the characteristics of a weak layer at the soil-rock interface of a slope.
[0049] Figure 2 This is a flowchart of a preferred embodiment of the present invention for detecting the reinforcement effect of slope engineering test points under the condition of weak soil-rock interface;
[0050] Figure 3 This is a flowchart of a preferred embodiment of the present invention for evaluating the deformation of the weak layer at the soil-rock interface of a slope. Detailed Implementation
[0051] like Figure 1 As shown, the present invention provides a method for reinforcing the weak layer characteristics of the soil-rock interface on a slope, comprising the following steps:
[0052] S101, the weak layer area of the soil-rock interface on the slope is detected by the stratum detection equipment; the reinforcement effect of the slope engineering detection point under the condition of the weak layer of the soil-rock interface is detected; and the deformation of the weak layer of the soil-rock interface on the slope is evaluated; the specific position of each drainage board is determined in the weak layer area of the soil-rock interface on the slope by using a small bamboo stick, the insertion machine is centered and leveled, and the drainage board is placed on the drill bit. The drainage board is a plastic drainage board.
[0053] S102, start the pile driver to hammer the drill rod, send the drainage board into the designed depth of the weak layer of soil-rock interface on the slope, lift the drill rod up, cut the drainage board on the ground, leaving a certain length of spare length, fill sand around the drainage board to complete the construction of this drainage board; drain the weak layer of soil-rock interface on the slope.
[0054] S103, vertical drainage wells are set up in the weak layer of soil-rock interface, which are made of medium or coarse sand. A steel pipe with a buried pile shoe at the lower end is driven into the soil, and then sand is poured in from the upper end and compacted in layers. At the same time, the steel pipe is arched upward until the pile hole is filled with sand to form a sand well. In cohesive soil, wooden piles can also be driven in first, and after the piles are pulled out, sand is filled in the hole and compacted for reinforcement.
[0055] like Figure 2 As shown, the method for detecting the reinforcement effect of slope engineering testing points under the condition of weak soil-rock interface provided by the present invention is as follows:
[0056] S201, Sensor Installation:
[0057] Five detection points were selected in the weak soil-rock interface layer of the slope with the same area and weight ratio. Six pressure sensors were installed at equal intervals on the upper surface of each detection point, and six displacement sensors were installed at equal intervals on the lower surface of each detection point. Both pressure sensors and displacement sensors were connected to an external computer.
[0058] S202, Installation of detection points:
[0059] The detection points of the weak soil-rock interface layer on the slope were divided into six equal parts. Then, three weak soil-rock interface layers of different depths and three weak soil-rock interface layers of the same depth were selected. The detection points of the six parts of the weak soil-rock interface layer were placed into the six weak soil-rock interface layers in sequence. After placement, the detection points in the weak soil-rock interface layer were backfilled with soil. After backfilling, the dry density of the backfilled soil was made consistent with the dry density of the surrounding soil.
[0060] S203, Simulated Rainfall:
[0061] Rainfall devices were installed above the weak soil-rock interface layers at three different depths of slopes to ensure that the rainfall amount and duration were the same. Then, rainfall devices were installed above the weak soil-rock interface layers at three slopes of the same depth, but with different rainfall amounts.
[0062] S204, pull-out test, load-bearing test and experimental analysis:
[0063] Pull rings are installed at the four corners of each testing point, and one end of each of the four traction ropes is fixed to the four pull rings. Then, the other end of each of the four traction ropes is connected to a tension gauge, which is then connected to an external computer.
[0064] After rainfall for one hour on the weak soil-rock interface layer of each slope, pull the tension gauges on each traction rope to apply a pull load to the detection point until the backfill soil heaves and fails. At this time, the pressure sensor, displacement sensor and tension gauge will transmit data to an external computer during the pulling process, and the computer will record the data.
[0065] The detection points were reset and a rain-driving device was installed. One hour after the rain started, a pressing device was set up above each detection point and put into operation until the detection point was completely submerged in the soil. During the pressing process, an external computer recorded the values of the pressure sensor and the displacement sensor.
[0066] After the pull-out and bearing capacity tests are completed, the data from the pressure sensor, displacement sensor, and tension gauge are recorded by the computer. By analyzing the data on the pull-out performance and bearing capacity of the weak soil-rock interface foundation of the slope, and by combining the area and weight of the test points with the actual area and weight of the test points of the weak soil-rock interface of the slope, the pull-out bearing capacity data value of the actual weak soil-rock interface test points of the slope can be obtained.
[0067] After the pressure sensor and displacement sensor provided by this invention are installed, a layer of PVC film is covered on both the upper and lower surfaces of the detection point of the weak layer at the soil-rock interface of the slope.
[0068] The present invention provides a method for backfilling detection points in the weak layer of the soil-rock interface of a slope in three stages, with each backfill being compacted.
[0069] The rain-spraying device provided by this invention uses nozzles for spraying. The number of nozzles above each detection point is set to 3 to 6. Rainwater is pumped out, acidic substances are added to the rainwater, and a fan blows the rainwater during the rainfall to make it more realistically simulate rainy weather.
[0070] The pressing device provided by the present invention uses a hydraulic cylinder to drive the pressing plate to work, so that the pressing plate presses the detection point.
[0071] After the experimental analysis provided by this invention is completed, the results are recorded in a book for easy reference in the future.
[0072] like Figure 3 As shown, the method for evaluating the deformation of the weak layer at the soil-rock interface of a slope provided by this invention is as follows:
[0073] S301, construct a stratigraphic database, and store the data of the weak layer of the soil-rock interface on the slope into the stratigraphic database; obtain the settlement data of the weak layer of the soil-rock interface on the slope, the settlement data including the settlement amount and the circumference angle; perform fitting processing on the settlement data through Fourier series expression to obtain the fitted harmonic amplitude and phase angle.
[0074] S302, obtain the radial deformation value to be evaluated of the weak layer of the soil-rock interface of the slope according to the harmonic amplitude, the phase angle and the preset radial deformation calculation formula; obtain the evaluation result according to the radial deformation value to be evaluated of the weak layer of the soil-rock interface of the slope and the preset rules and display it.
[0075] The preset formula for calculating radial deformation is obtained based on simulation experiments using a full finite element model, as follows:
[0076]
[0077] Where y is the radial deformation value, n is the harmonic number, and θ is the circumferential angle. It is the phase angle of the nth harmonic when they are superimposed. kn is a function of the amplitude un of the nth harmonic settling.
[0078] The Fourier series expression provided by this invention is as follows:
[0079]
[0080] Where u is the settlement, θ is the circular angle, 0≤θ≤2π, u0 is the overall uniform settlement of the weak layer at the soil-rock interface of the slope, un is the amplitude of the nth harmonic settlement, and n is the harmonic number. Let n be the phase angle of the nth harmonic during superposition.
[0081] The present invention provides a method for obtaining the radial deformation value of the weak layer at the soil-rock interface of a slope based on the harmonic amplitude, the phase angle, and a preset radial deformation calculation formula, including:
[0082] Based on different orders, the calculation formula for the corresponding order is obtained from the radial deformation calculation formula.
[0083] The radial deformation value for the corresponding order is obtained by using the calculation formula for the corresponding order, the harmonic amplitude value, and the phase angle.
[0084] By superimposing the radial deformation values at different orders, the radial deformation curves after settlement of the weak layer at the soil-rock interface of the slope are obtained.
[0085] The radial deformation value to be evaluated is obtained based on the radial deformation curve.
[0086] The process of obtaining and displaying the evaluation results based on the radial deformation value of the weak layer at the soil-rock interface of the slope and preset rules includes:
[0087] If the radial deformation value to be evaluated is less than the preset value, the evaluation result is that the deformation of the weak layer of the soil-rock interface on the slope is within the standard, indicating that the weak layer of the soil-rock interface on the slope is qualified; otherwise, the evaluation result is that the deformation of the weak layer of the soil-rock interface on the slope exceeds the standard, indicating that the weak layer of the soil-rock interface on the slope is unqualified.
[0088] The process of acquiring settlement data of the weak layer at the soil-rock interface of the slope includes: setting vertical displacement observation points on the edge of the weak layer at the soil-rock interface of the slope, setting horizontal displacement side stakes at the locations of the vertical displacement observation points, and collecting settlement data at the locations of the horizontal displacement side stakes using a level.
[0089] To demonstrate the inventiveness and technical value of the technical solution of this invention, this section provides specific product or related technology application examples of the technical solution claimed.
[0090] This invention provides a method for testing the reinforcement effect of slope engineering test points under conditions of weak soil-rock interface. It sets up weak soil-rock interface layers at different depths, with the same rainfall, and weak soil-rock interface layers at the same depth, with different rainfall. Pull-out and bearing capacity tests are then conducted on the test points at the weak soil-rock interface. This allows for multiple sets of comparative experiments, ensuring the accuracy of the tests and overcoming the limitations of traditional experimental results. This enables personnel to better assess the performance of the test points at the weak soil-rock interface. Simultaneously, the method for evaluating the deformation of the weak soil-rock interface layer can accurately assess its deformation.
[0091] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated-design hardware. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented by hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or by software executed by various types of processors, or by a combination of the above-described hardware circuitry and software, such as firmware.
[0092] The embodiments of the present invention have achieved some positive results during the research and development or use process, and have indeed great advantages compared with the prior art. The following content describes them in conjunction with the data, charts and other information of the experimental process.
[0093] This invention provides a method for testing the reinforcement effect of slope engineering test points under conditions of weak soil-rock interface. It sets up weak soil-rock interface layers at different depths, with the same rainfall, and weak soil-rock interface layers at the same depth, with different rainfall. Pull-out and bearing capacity tests are then conducted on the test points at the weak soil-rock interface. This allows for multiple sets of comparative experiments, ensuring the accuracy of the tests and overcoming the limitations of traditional experimental results. This enables personnel to better assess the performance of the test points at the weak soil-rock interface. Simultaneously, the method for evaluating the deformation of the weak soil-rock interface layer can accurately assess its deformation.
[0094] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.
Claims
1. A method for reinforcing the engineering properties of slopes under weak soil-rock interface conditions, characterized in that: Includes the following steps: (1) The weak layer area of the soil-rock interface on the slope is detected by the geological detection equipment; the reinforcement effect of the slope engineering detection point under the condition of the weak layer of the soil-rock interface is detected; and the deformation of the weak layer of the soil-rock interface on the slope is evaluated; the specific position of each drainage board is determined by the small bamboo stick in the weak layer area of the soil-rock interface on the slope, the insertion machine is centered and leveled, and the drainage board is placed on the drill bit. (2) Start the pile driver to hammer the drill rod, send the drainage board into the design depth of the weak layer of the soil-rock interface of the slope, lift the drill rod up, cut the drainage board on the ground and leave a certain length of spare length, fill sand around the drainage board to complete the construction of this drainage board; drain the weak layer of the soil-rock interface of the slope. (3) Set up vertical drainage wells in the weak layer of soil-rock interface, which are made of medium or coarse sand. Drive steel pipes with embedded pile shoes at the lower end into the soil, and then pour sand from the upper end, compact in layers, and arch the steel pipes upward until the pile hole is filled with sand to form a sand well; drive wooden piles into cohesive soil first, and after pulling out the piles, fill the hole with sand and compact it to reinforce it. The method for detecting the reinforcement effect of slope engineering testing points under the condition of weak soil-rock interface is as follows: (1) Sensor installation: Five detection points were selected in the weak soil-rock interface layer of the slope with the same area and weight ratio. Six pressure sensors were installed at equal distances on the upper surface of each detection point, and six displacement sensors were installed at equal distances on the lower surface of each detection point. Both pressure sensors and displacement sensors were connected to an external computer. (2) Installation of detection points: The detection points of the weak soil-rock interface layer on the slope were divided into six parts. Then, three weak soil-rock interface layers of different depths and three weak soil-rock interface layers of the same depth were selected. The detection points of the six parts of the weak soil-rock interface layer were placed into the six weak soil-rock interface layers in sequence. After placement, the detection points in the weak soil-rock interface layer were backfilled with soil. After backfilling, the dry density of the backfilled soil was made consistent with the dry density of the surrounding soil. (3) Simulated rainfall: Rainfall devices were installed above the weak soil-rock interface layers at three different depths of slopes to ensure that the rainfall amount and duration were the same. Then, rainfall devices were installed above the weak soil-rock interface layers at three slopes of the same depth, but with different rainfall amounts. (4) Pull-out test, load-bearing test and experimental analysis: Pull rings are installed at the four corners of each detection point, and one end of each of the four traction ropes is fixed to the four pull rings. Then, the other end of each of the four traction ropes is connected to a tension gauge, which is then connected to an external computer. After rainfall for one hour on the weak layer of soil-rock interface on each slope, pull the tension gauge on each traction rope to apply pull load to the detection point until the backfill soil heaves and breaks. At this time, the pressure sensor, displacement sensor and tension gauge will transmit data to the external computer during the pulling process, and the computer will record the data. The detection points were reset and a rain-driving device was installed. One hour after the rain, a pressing device was set up above each detection point and operated until the detection point was completely submerged in the soil. During the pressing process, an external computer recorded the values of the pressure sensor and the displacement sensor. After the pull-out and bearing capacity tests are completed, the data from the pressure sensor, displacement sensor and tension gauge are recorded by the computer. By analyzing the data of the pull-out performance and bearing capacity of the weak layer of the soil-rock interface foundation on the slope, and by combining the area and weight of the test points with the actual area and weight of the test points of the weak layer of the soil-rock interface on the slope, the pull-out bearing capacity data value of the actual test points of the weak layer of the soil-rock interface on the slope can be obtained. The method for evaluating the deformation of the weak layer at the soil-rock interface of a slope is as follows: 1) Construct a stratigraphic database and store the data of the weak layer of the soil-rock interface on the slope into the stratigraphic database; obtain the settlement data of the weak layer of the soil-rock interface on the slope, the settlement data including the settlement amount and the circumferential angle; fit the settlement data through a Fourier series expression to obtain the fitted harmonic amplitude and phase angle. 2) Obtain the radial deformation value to be evaluated for the weak layer of the soil-rock interface on the slope based on the harmonic amplitude, the phase angle, and the preset radial deformation calculation formula; The evaluation results are obtained and displayed based on the radial deformation value of the weak layer at the soil-rock interface of the slope and the preset rules. The preset formula for calculating radial deformation is obtained based on simulation experiments using a full finite element model, as follows: Where y is the radial deformation value, n is the harmonic number, and θ is the circumferential angle. It is the phase angle of the nth harmonic when they are superimposed. kn is a function of the amplitude un of the nth harmonic settling; The step of obtaining the radial deformation value to be evaluated for the weak layer at the soil-rock interface of the slope based on the harmonic amplitude, the phase angle, and a preset radial deformation calculation formula includes: Based on different orders, the calculation formula for the corresponding order is obtained from the radial deformation calculation formula; The radial deformation value for the corresponding order is obtained by using the calculation formula for the corresponding order, the harmonic amplitude value, and the phase angle. By superimposing the radial deformation values at different orders, the radial deformation curve of the weak layer at the soil-rock interface of the slope after settlement is obtained. The radial deformation value to be evaluated is obtained based on the radial deformation curve. The process of obtaining and displaying the evaluation results based on the radial deformation value of the weak layer at the soil-rock interface of the slope and preset rules includes: If the radial deformation value to be evaluated is less than the preset value, the evaluation result is that the deformation of the weak layer of the soil-rock interface on the slope is not excessive, indicating that the weak layer of the soil-rock interface on the slope is qualified; otherwise, the evaluation result is that the deformation of the weak layer of the soil-rock interface on the slope exceeds the standard, indicating that the weak layer of the soil-rock interface on the slope is unqualified. The process of acquiring settlement data of the weak layer at the soil-rock interface of the slope includes: setting vertical displacement observation points on the edge of the weak layer at the soil-rock interface of the slope, setting horizontal displacement side stakes at the locations of the vertical displacement observation points, and collecting settlement data at the locations of the horizontal displacement side stakes using a level.
2. The method for reinforcing slope engineering characteristics under weak soil-rock interface conditions as described in claim 1, characterized in that: After the pressure sensor and displacement sensor are installed, a layer of PVC film is placed on both the upper and lower surfaces of the detection point in the weak layer of the soil-rock interface on the slope.
3. The method for reinforcing slope engineering characteristics under weak soil-rock interface conditions as described in claim 1, characterized in that: When backfilling the detection points in the weak layer of the soil-rock interface on the slope, the soil is backfilled in three stages, and the backfilled soil is compacted after each backfilling.
4. The method for reinforcing slope engineering characteristics under weak soil-rock interface conditions as described in claim 1, characterized in that: The rain-spraying device uses nozzles for spraying, with 3 to 6 nozzles above each detection point. Rainwater is pumped out, and acidic substances are added to the rainwater. During the rainfall, a fan blows the rainwater to more realistically simulate rainy weather.
5. The method for reinforcing slope engineering characteristics under weak soil-rock interface conditions as described in claim 1, characterized in that: The pressing device uses a hydraulic cylinder to drive the pressing plate, which then presses the detection point.
6. The method for reinforcing slope engineering characteristics under weak soil-rock interface conditions as described in claim 1, characterized in that: After the experimental analysis is completed, the results will be recorded in a book for future reference.
7. The method for reinforcing slope engineering characteristics under weak soil-rock interface conditions as described in claim 1, characterized in that, The Fourier series expression is as follows: Where u is the settlement, θ is the circular angle, 0≤θ≤2π, u0 is the overall uniform settlement of the weak layer at the soil-rock interface of the slope, un is the amplitude of the nth harmonic settlement, and n is the harmonic number. Let n be the phase angle of the nth harmonic during superposition.
Citation Information
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