Underground diaphragm wall guide ditch excavation method

Abstract

The invention discloses an underground diaphragm wall guide ditch excavation method which comprises the steps that a guide ditch is divided into a plurality of units for modular excavation and supporting, after earth excavation of a current guide ditch is completed, earth excavation of a next guide ditch is conducted, and meanwhile slope supporting of a previous guide ditch is conducted. The whole guide ditch can be divided into a plurality of units to be constructed step by step, risk pre-judgment can be carried out according to geological and environmental factors, earth excavation and slope supporting are carried out in order, the excavation efficiency can be improved, and meanwhile the engineering safety is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of ground-connected walls, and more specifically, to a method for excavating a guide trench for a ground-connected wall. Background Art

[0002] The underground continuous wall is a foundation project. A trenching machine is used to dig a narrow guide trench on the surface of the roadbed, and then manual excavation is carried out. After the trench is cleared, a steel cage is suspended in the trench, and then underwater concrete is poured using the conduit method to build a unit trench section. This is done section by section to build a continuous reinforced concrete wall underground as a water interception, anti-seepage, load-bearing, and water-retaining structure. Although the existing guide trench excavation technology has made certain progress, there are still many shortcomings. For example, the traditional construction method directly digs the guide trench in one go according to the planned length of the ground-connected wall project. It is not adaptable to complex geological conditions and has low construction efficiency. If the excavation speed is too fast, the support is not timely or insufficient, etc., it may also cause damage to the soil structure and there is a risk of soil collapse. Summary of the invention

[0003] The present invention provides a method for excavating a ground-anchored wall guide trench, which can divide the entire guide trench into multiple units for step-by-step construction, thereby enabling risk prejudgment based on geological and environmental factors, allowing earth excavation and slope support to proceed in an orderly manner, thereby improving excavation efficiency and ensuring the safety of the project.

[0004] In order to achieve these purposes and other advantages according to the present invention, a method for excavating a ground-anchored wall guide trench is provided, including: dividing the guide trench into multiple units for modular excavation and support, and after the excavation of the current guide trench is completed, the excavation of the next guide trench is started, and the slope support of the previous guide trench is started at the same time.

[0005] Preferably, earth excavation specifically includes: First, carry out manual surface clearing to remove gravel and garbage on the roadbed surface, use dump trucks to excavate the surface soil and transport it away; secondly, use excavators to excavate the middle layer of soil, and excavate the guide ditch to more than 30cm above the designed elevation. Over-excavation and root cutting are strictly prohibited; finally, use manual excavation, trench cleaning and slope repair to excavate the guide ditch to the designed elevation and leave the site.

[0006] Preferably, the manual excavation is achieved by using a step-type cart, the step-type cart comprising: A frame having a V-shaped structure, a handle is provided at the rear end of the frame, and wheels are provided at the bottom of the frame; A bucket is arranged at the front end of the frame, the bucket is rotatably connected to the front end of the frame through a driving rod, and the driving rod causes the bucket to swing under power drive; A pressure roller, which is arranged at the rear end of the frame, the pressure roller is rotatably connected to the rear end of the frame through an H-shaped connecting frame, and the pressure roller and the wheel are located at the same adhesion surface height; Among them, the step-by-step cart moves forward, and the power drives the bucket to complete the excavation of the current section, and then continues to move forward to the next two sections, and the bucket dumps the soil and transports it away. At the same time, the step-by-step cart completes the soil compaction of the previous section and the current section, and then the step-by-step cart retreats backward to the next section to prepare for earth excavation. At the same time, the step-by-step cart completes the secondary soil compaction of the current section, and the step-by-step cart repeats the above-mentioned two-step forward and one-step backward stroke, and the step-by-step cart completes the third soil compaction of the current section.

[0007] Preferably, when excavating earthwork, if over-excavation occurs, backfill soil is immediately used to fill to the designed height and then compacted; when excavating earthwork, if groundwater is encountered, water is immediately drained, the soil in the guide ditch is replaced, and the soil is kept dry.

[0008] Preferably, the slope support specifically includes: First, insert the Larsen steel sheet piles and steel pipe piles vertically into the pile positions alternately, drive the piles, and sink the piles; secondly, install the corbels at the same height of the steel pipe piles, place the steel purlins on the corbels and weld them to form an integral part with the steel pipe piles; finally, install support rods between the opposite steel purlins to achieve lateral support.

[0009] Preferably, the slope support adopts a hanging corbel in combination with a steel pipe pile, the top of the steel pipe pile has an annular slot, the hanging corbel includes a corbel hanging plate, the bottom of the corbel hanging plate has a leg support portion to place the steel purlin, the back of the corbel hanging plate has a wedge-shaped plug to be suspended in the annular slot, the outer surface of the wedge-shaped plug is an inclined surface, and the size gradually decreases from top to bottom. When the corbel hanging plate is welded to the steel purlin, the inclined surface of the wedge-shaped plug fits the inner surface of the annular slot.

[0010] The present invention has at least the following beneficial effects: First, the present invention divides the entire guide ditch into multiple units for modular construction. It can predict the risks of geological and environmental factors of the soil in front when excavating the current unit, and perform optimization analysis from the perspective of safety and efficiency, so that the excavation and slope support can be carried out in an orderly manner, paying attention to issues such as the stability of the guide ditch and the safety of the support structure, which can improve the excavation efficiency and ensure the safety of the project.

[0011] Second, the guide ditch is divided into multiple units according to the size, shape and position of the guide ditch, as well as geological conditions and surrounding environmental factors. Each unit represents a guide ditch of a specific length and depth. The excavation and support of the guide ditch can be carried out independently. There is no need for immediate support after excavation. The next guide ditch can be excavated and the slope support of the previous guide ditch can be carried out simultaneously, so that the previous guide ditch and the current guide ditch form a continuous wall. The dynamic changes of the wall, such as the stress state and deformation trend, are monitored in real time to ensure the effectiveness of the support operation. If there is any abnormality, necessary adjustment measures can be taken to ensure the depth of the guide ditch and the stability of the wall, which significantly improves the safety and stability of the support operation.

[0012] Third, before excavating the earthwork, the amount of earthwork excavation for the guide ditch should be considered. During the excavation, dump trucks are used for transportation, excavators are used for trenching, and manual trimming is used to reach the designed elevation. When digging trenches with excavators, the principle of deep first and shallow later is followed. The model of the excavator is selected according to the amount of work for the guide ditch and the working environment of the construction site. The bucket of the excavator is selected according to the bottom width of the guide ditch. Crawler excavators are preferred to improve the efficiency of the use of construction machinery and reduce the cost of using construction machinery. Manually trim the bottom edge of the guide ditch, cut off the excess guide ditch slope, clean the bottom guide ditch to the designed elevation, and do not over-dig to avoid uneven bottom edge of the guide ditch, insufficient bottom width of the guide ditch, and substandard cushioning of the bottom edge of the guide ditch.

[0013] Fourth, the use of mechanical devices in conjunction with manual excavation can further improve construction efficiency and ensure construction results. The step-type cart can not only clear the bottom of the ditch and ensure the flatness of the bottom edge of the ditch, but also ensure the bottom width and depth of the ditch excavation at any time. When cleaning the bottom edge of the ditch, the cleared soil can be cleaned out of the ditch by the excavator. The wheels and rollers of the frame are located at the same attachment surface height. When not in use, the wheels and rollers are supported on the roadbed surface at the same time. A handle is provided at the rear end of the frame to facilitate pushing the frame. A bucket is provided at the front end of the frame. The bucket swings back and forth under power drive and can be logically swung in the form of electric motor drive. When in use, when the bucket swings backward, the soil is scooped into the bucket. After the frame moves forward to a predetermined position, the bucket swings forward to dump the soil inside the bucket. A roller is also provided at the rear end of the frame to flatten the bottom edge of the guide ditch to ensure the flatness of the bottom edge of the guide ditch. The bucket specifications and roller specifications can be selected according to the bottom width of the guide ditch. When using a step-type cart, a unit of the guide ditch can be divided into multiple sections, and a section can be subjected to three forward-reverse-forward soil tests. Rolling, the walking cart excavates the nth section, then moves to the n+2th section, dumps the soil to the n+2th section, and the excavator cooperates to clean the n+2th section out of the guide ditch. This process is the first rolling of the nth section. The walking cart retreats to the n+1th section to excavate the soil. This process is the second rolling of the nth section, then moves to the n+3th section, dumps the soil to the n+3th section, and the excavator cooperates to clean the accumulated soil of the n+3th section out of the guide ditch. This process is the third rolling of the nth section. The accumulated soil is directly piled on the bottom of the guide ditch, keeping a distance from the guide ditch slope, paying attention to the stacking height, and using a long-arm excavator to lift the soil out, which can not only achieve ditch digging and bottom clearing, but also flatten the bottom of the guide ditch, improving the effect of manual excavation.

[0014] Fifth, avoid over-excavation during earthwork excavation and do not disturb the original soil. If over-excavation occurs, backfill soil should be used immediately and compacted to ensure the bearing capacity of the backfill soil. If groundwater is encountered during earthwork excavation, rainwater should be drained in time to keep the trench dry, appropriately reduce the excavation width and slope gradient, and take appropriate support measures. It is preferred to set up drainage ditches on both sides of the guide ditch and set up drainage wells every 50m.

[0015] Sixth, the slope support adopts prefabricated components for on-site assembly, which reduces the complexity of support construction and is economical and feasible. The combination of Larsen steel sheet piles and steel pipe piles, with steel purlins and support rods, can fully adapt to complex and changeable geological conditions and effectively improve the stability of the guide ditch. Steel pipe piles can be arranged at a certain interval. The order of piling is from front to back according to the site conditions. The first steel pipe piles can accurately locate the pile foundation, and then the Larsen steel sheet piles can be vertically positioned to serve as a temporary drainage and support barrier. During the construction process, steel purlins and support rods are set up in time for enclosure to form a horizontal support as a whole. The support position of the support rod is determined according to the soil environment. It is suitable for the changeable working conditions on site, effectively ensuring that the steel support force reaches the preset value and ensuring the safety of construction.

[0016] Seventh, the stability of the lateral support is further improved by means of stress transfer. The design of the suspended corbel is coordinated with the steel pipe pile. The corbel is not easy to deform or break, and the overall loading and unloading operation is simple, stable and reliable. An annular blind groove is set on the top of the steel pipe pile to form a slot, which is convenient for the hanging and insertion of the wedge-shaped plug of the corbel. The outer surface of the wedge-shaped plug is an inclined surface. When inserted, the lower part does not contact and a gap is formed. After insertion, the corbel hanging plate and the steel pipe pile are welded to make the corbel hanging plate and the steel pipe pile tightly connected. The wedge-shaped plug is deflected, so that the inclined surface of the wedge-shaped plug fits with the inner surface of the slot and forms stress. Especially after the steel purlin is welded and installed on the leg support part and the support rod is installed between the steel purlin, the wedge-shaped plug further applies a top force to make the steel pipe pile and the corbel tightly combined into a whole, effectively ensuring that the supporting force reaches the preset value, and the safety is higher.

[0017] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic structural diagram of a step-type cart according to a technical solution of the present invention; Figure 2 A schematic diagram of a slope support according to a technical solution of the present invention; Figure 3 The present invention is a schematic structural diagram of a suspended corbel according to a technical solution of the present invention. DETAILED DESCRIPTION

[0019] The present invention is further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0020] It should be understood that the terms such as “having”, “including” and “comprising” used herein do not exclude the existence or addition of one or more other elements or combinations thereof.

[0021] It should be noted that the experimental methods described in the following embodiments are conventional methods unless otherwise specified, and the reagents and materials can be obtained from commercial sources unless otherwise specified; in the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "set" should be understood in a broad sense, for example, they can be fixedly connected, set, or detachably connected, set, or connected and set in one piece. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood in specific circumstances. The orientation or position relationship indicated by the terms "lateral", "longitudinal", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. is based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0022] The present invention provides a method for excavating a ground-connected wall guide ditch, comprising: dividing the guide ditch into a plurality of units for modular excavation and support, and after the earthwork excavation of the current guide ditch is completed, the earthwork excavation of the next guide ditch is started, and the slope support of the previous guide ditch is started at the same time.

[0023] In the above technical scheme, by dividing the entire guide ditch into multiple units for modular construction, the risk of geological and environmental factors of the soil ahead can be predicted during the excavation of the current unit, and an optimization analysis can be performed from the perspective of safety and efficiency, so that the excavation and slope support can be carried out in an orderly manner, paying attention to issues such as the stability of the guide ditch and the safety of the support structure, which can improve the excavation efficiency and ensure the safety of the project.

[0024] According to the size, shape and position of the guide ditch, as well as geological conditions and surrounding environmental factors, the guide ditch is divided into multiple units. Each unit represents a guide ditch of a specific length and depth. The excavation and support of the guide ditch can be carried out independently. There is no need for immediate support after excavation. The next guide ditch can be excavated and the slope support can be carried out on the previous guide ditch simultaneously, so that the previous guide ditch and the current guide ditch form a continuous wall. The dynamic changes of the wall, such as the stress state and deformation trend, are monitored in real time to ensure the effectiveness of the support operation. If there is any abnormality, necessary adjustment measures can be taken to ensure the depth of the guide ditch and the stability of the wall, significantly improving the safety and stability of the support operation.

[0025] In another technical solution, earth excavation specifically includes: First, carry out manual surface clearing to remove gravel and garbage on the roadbed surface, use dump trucks to excavate the surface soil and transport it away; secondly, use excavators to excavate the middle layer of soil, and excavate the guide ditch to more than 30cm above the designed elevation. Over-excavation and root cutting are strictly prohibited; finally, use manual excavation, trench cleaning and slope repair to excavate the guide ditch to the designed elevation and leave the site.

[0026] In the above technical scheme, before earth excavation, the amount of earth excavation for the guide ditch should be considered. During earth excavation, dump trucks are used for transportation, excavators are used for trenching, and manual trimming is used to reach the designed elevation. When digging trenches with excavators, the principle of deep first and shallow later is followed. The model of the excavator is selected according to the amount of work for the guide ditch and the working environment of the construction site. The bucket 3 of the excavator is selected according to the bottom width of the guide ditch. A crawler excavator is preferably selected to improve the efficiency of the use of construction machinery and reduce the cost of using construction machinery. Manually trim the bottom edge of the guide ditch, cut off the excess guide ditch slope, clean the bottom guide ditch to the designed elevation, and do not over-dig to avoid uneven bottom edge of the guide ditch, insufficient bottom width of the guide ditch, and non-compliant cushion layer of the bottom edge of the guide ditch.

[0027] like Figure 1 As shown, in another technical solution, manual excavation is achieved by using a step-type cart, and the step-type cart includes: A frame 1 is a V-shaped structure, a handle is provided at the rear end of the frame 1, and a wheel 2 is provided at the bottom of the frame 1; A bucket 3 is disposed at the front end of the vehicle frame 1, and the bucket 3 is rotatably connected to the front end of the vehicle frame 1 through a driving rod, and the driving rod causes the bucket 3 to swing under power drive; A pressure roller 4 is arranged at the rear end of the frame 1, the pressure roller 4 is rotatably connected to the rear end of the frame 1 through an H-shaped connecting frame, and the pressure roller 4 and the wheel 2 are located at the same adhesion surface height; Among them, the step-by-step cart moves forward, and the power drives the bucket 3 to complete the earth excavation of the current section, and then continues to move forward to the next two sections, and the bucket 3 dumps the soil and transports it away. At the same time, the step-by-step cart completes the soil compaction of the previous section and the current section, and then the step-by-step cart retreats backward to the next section to prepare for earth excavation. At the same time, the step-by-step cart completes the secondary soil compaction of the current section, and the step-by-step cart repeats the above-mentioned two-step forward and one-step backward stroke, and the step-by-step cart completes the third soil compaction of the current section.

[0028] In the above technical scheme, the use of mechanical devices in conjunction with manual excavation can further improve construction efficiency and ensure construction results. The step-type cart can not only clear the bottom of the guide ditch and ensure the flatness of the bottom edge of the guide ditch, but also ensure the bottom width and depth of the guide ditch excavation at any time. When cleaning the bottom edge of the guide ditch, the cleared soil can be cleaned out of the guide ditch by the excavator. The wheels 2 and the pressure rollers 4 of the frame 1 are located at the same attachment surface height. When not in use, the wheels 2 and the pressure rollers 4 are supported on the roadbed surface at the same time. A handle is provided at the rear end of the frame 1 to facilitate pushing the frame 1. A bucket 3 is provided at the front end of the frame 1. The bucket 3 swings back and forth under power drive and can be logically swung in the form of electric motor drive. When in use, when the bucket 3 swings backward, the soil is shoveled into the bucket 3. After the frame 1 moves forward to a predetermined position, the bucket 3 swings forward to dump the soil inside the bucket 3. A pressure roller 4 is also provided at the rear end of the frame 1 to flatten the bottom edge of the guide ditch to ensure the flatness of the bottom edge of the guide ditch. The specifications of the bucket 3 and the pressure roller 4 can be selected according to the bottom width of the guide ditch. When using a step-type cart, a unit of the guide ditch can be divided into multiple sections, and a section can be positively moved. - Reverse-forward three times of soil rolling, the walking cart excavates the nth section, then moves to the n+2th section, dumps the soil to the n+2th section, and the excavator cooperates to clean the n+2th section out of the guide ditch. This process is the first rolling of the nth section. The walking cart retreats to the n+1th section to excavate the soil. This process is the second rolling of the nth section, then moves to the n+3th section, dumps the soil to the n+3th section, and the excavator cooperates to clean the accumulated soil of the n+3th section out of the guide ditch. This process is the third rolling of the nth section. The accumulated soil is directly piled on the bottom of the guide ditch, keeping a distance from the guide ditch slope, paying attention to the stacking height, and using a long-arm excavator to lift the soil out, which can not only achieve ditch digging and bottom clearing, but also flatten the bottom of the guide ditch, improving the effect of manual excavation.

[0029] In another technical solution, when excavating earth, if over-excavation occurs, backfill soil is immediately used to fill to the designed height and then compacted; when excavating earth, if groundwater is encountered, water is immediately diverted and drained, the soil in the ditch is replaced, and the soil is kept dry.

[0030] In the above technical scheme, over-excavation should be avoided during earthwork excavation, and the original soil should not be disturbed. If over-excavation occurs, backfill soil should be used immediately and compacted to ensure the bearing capacity of the backfill soil. If groundwater is encountered during earthwork excavation, rainwater should be drained in time to keep the trench dry, appropriately reduce the excavation width and slope gradient, and take appropriate support measures. It is preferred to set drainage ditches on both sides of the guide ditch and set drainage wells every 50m.

[0031] like Figure 2 As shown, in another technical solution, the slope support specifically includes: First, the Larsen steel sheet piles 5 and the steel pipe piles 6 are alternately inserted vertically into the pile positions, piled, and sunk; secondly, the corbels 7 are installed at the same height of the steel pipe piles 6, and the steel purlins 8 are placed on the corbels 7 and welded to be integrally formed with the steel pipe piles 6; finally, the support rods 9 are installed between the opposite steel purlins 8 to achieve lateral support.

[0032] In the above technical solution, the slope support adopts prefabricated components for on-site assembly, which reduces the complexity of support construction and is economical and feasible. The Larsen steel sheet piles 5 and steel pipe piles 6 are used in combination with steel purlins 8 and support rods 9, which can fully adapt to complex and changeable geological conditions and effectively improve the stability of the guide ditch. The steel pipe piles 6 can be arranged at a certain interval, and the pile driving sequence is from front to back according to the site conditions. The steel pipe piles 6 are driven first to accurately locate the pile foundation, and then the Larsen steel sheet piles 5 are driven to vertically locate the pile foundation as a temporary drainage and support barrier. During the construction process, the steel purlins 8 and support rods 9 are set in time for enclosure to form a lateral support as a whole. The support position of the support rods 9 is determined according to the soil environment. It is suitable for the changeable working conditions on site, effectively ensuring that the steel support force reaches the preset value and ensuring the safety of the construction.

[0033] like Figure 3 As shown, in another technical solution, the slope support adopts a hanging corbel 7 in cooperation with a steel pipe pile 6, the top of the steel pipe pile 6 has an annular slot 10, the hanging corbel 7 includes a corbel hanging plate 11, the bottom of the corbel hanging plate 11 has a leg support portion 12 to place the steel purlin 8, the back of the corbel hanging plate 11 has a wedge-shaped plug 13 to be suspended in the annular slot 10, the outer surface of the wedge-shaped plug 13 is an inclined surface, and the size gradually decreases from top to bottom. When the corbel hanging plate 11 is welded to the steel purlin 8, the inclined surface of the wedge-shaped plug fits the inner surface of the annular slot 10.

[0034] In the above technical scheme, the stability of the lateral support is further improved by stress transfer, and the hanging bracket 7 is designed to cooperate with the steel pipe pile 6. The bracket 7 is not easy to deform and break, and the overall loading and unloading operation is simple, stable and reliable. An annular blind groove is set on the top of the steel pipe pile 6 to form a slot 10, which is convenient for the wedge-shaped plug 13 of the bracket 7 to be suspended and inserted. The outer surface of the wedge-shaped plug 13 is an inclined surface. When inserted, the lower part does not contact and a gap is formed. After insertion, the bracket hanging plate 11 and the steel pipe pile 6 are welded to make the bracket hanging plate 11 and the steel pipe pile 6 tightly connected, and the wedge-shaped plug 13 is deflected, so that the inclined surface of the wedge-shaped plug 13 is attached to the inner surface of the slot 10 and stress is formed. Especially after the steel purlin 8 is welded and installed on the leg support part 12, and the support rod 9 is installed between the steel purlin 8, the wedge-shaped plug 13 further applies a top force, so that the steel pipe pile 6 and the bracket 7 are tightly combined into a whole, effectively ensuring that the supporting force reaches the preset value, and the safety is higher.

[0035] The number of devices and processing scales described here are used to simplify the description of the present invention. Applications, modifications and variations of the present invention will be obvious to those skilled in the art.

[0036] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes, and they can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A method for digging a trench for a ground-connected wall, characterized in that: include: The guide ditch is divided into multiple units for modular excavation and support. After the excavation of the current guide ditch is completed, the excavation of the next guide ditch will be started, and the slope support of the previous guide ditch will be started at the same time.

2. The method for digging a trench for a ground-anchored wall according to claim 1, characterized in that: Earthwork excavation specifically includes: First, carry out manual surface clearing to remove gravel and garbage on the roadbed surface, use dump trucks to excavate the surface soil and transport it away; secondly, use excavators to excavate the middle layer of soil, and excavate the guide ditch to more than 30cm above the designed elevation. Over-excavation and root cutting are strictly prohibited; finally, use manual excavation, trench cleaning and slope repair to excavate the guide ditch to the designed elevation and leave the site.

3. The method for digging a trench for a ground-anchored wall according to claim 2, characterized in that: Manual excavation is achieved by using a walking cart, which includes: A frame having a V-shaped structure, a handle is provided at the rear end of the frame, and wheels are provided at the bottom of the frame; A bucket is arranged at the front end of the frame, the bucket is rotatably connected to the front end of the frame through a driving rod, and the driving rod causes the bucket to swing under power drive; A pressure roller, which is arranged at the rear end of the frame, the pressure roller is rotatably connected to the rear end of the frame through an H-shaped connecting frame, and the pressure roller and the wheel are located at the same adhesion surface height; Among them, the step-by-step cart moves forward, and the power drives the bucket to complete the excavation of the current section, and then continues to move forward to the next two sections, and the bucket dumps the soil and transports it away. At the same time, the step-by-step cart completes the soil compaction of the previous section and the current section, and then the step-by-step cart retreats backward to the next section to prepare for earth excavation. At the same time, the step-by-step cart completes the secondary soil compaction of the current section, and the step-by-step cart repeats the above-mentioned two-step forward and one-step backward stroke, and the step-by-step cart completes the third soil compaction of the current section.

4. The method for digging a trench for a ground-anchored wall according to claim 2, characterized in that: During earth excavation, if over-excavation occurs, immediately backfill the soil to the designed height and then tamp it; during earth excavation, if groundwater is encountered, immediately divert the water and drain the water, replace the soil in the ditch, and keep the soil dry.

5. The method for digging a trench for a ground-anchored wall according to claim 2, characterized in that: Slope support specifically includes: First, insert the Larsen steel sheet piles and steel pipe piles vertically into the pile positions alternately, drive the piles, and sink the piles; secondly, install the corbels at the same height of the steel pipe piles, place the steel purlins on the corbels and weld them to form an integral part with the steel pipe piles; finally, install support rods between the opposite steel purlins to achieve lateral support.

6. The method for digging a trench for a ground-anchored wall as claimed in claim 5, characterized in that: The slope support adopts a hanging corbel in combination with a steel pipe pile. The top of the steel pipe pile is provided with an annular slot. The hanging corbel includes a corbel hanging plate. The bottom of the corbel hanging plate is provided with a leg support portion for placing a steel purlin. The back of the corbel hanging plate is provided with a wedge-shaped plug to be hung in the annular slot. The outer surface of the wedge-shaped plug is an inclined surface, and the size gradually decreases from top to bottom. When the corbel hanging plate is welded to the steel purlin, the inclined surface of the wedge-shaped plug fits the inner surface of the annular slot.

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