A prestressed load monitoring and adjustable counterweight composite retaining wall and construction method

Abstract

The present invention discloses a prestressed monitoring adjustable counterweight composite retaining wall and a construction method, comprising a counterweight composite retaining wall body, a prestressed anchor cable, and a pressure sensor. A through hole is provided on the bottom plate of the counterweight support structure of the counterweight composite retaining wall body. The anchor cable head end of the prestressed anchor cable passes through the through hole and is fixed above the bottom plate of the counterweight support structure by an anchor. The anchoring end of the prestressed anchor cable is arranged in a foundation borehole, and the pressure sensor is arranged between the anchor and the bottom plate of the counterweight support structure. The present invention has a simple structure and can monitor the anchor cable tension changes in real time during the construction of the counterweight composite retaining wall body and the operation and use stage after completion, so as to judge the stability of the entire counterweight composite retaining wall, and make adjustments according to the situation to improve the stability and seismic resistance of the counterweight composite retaining wall.

Description

Technical Field

[0001] The invention belongs to the technical field of retaining walls, and in particular relates to a prestressed monitoring adjustable counterweight type combined retaining wall and a construction method. Background Art

[0002] Retaining walls have been widely used in transportation and municipal engineering, railway engineering, building slopes and foundation pits, etc. Single cantilever retaining structures, buttress retaining walls and gravity retaining walls are only suitable for 6 The support height is ~10 meters, so a counterweight composite retaining wall is produced with a buttress or gravity retaining wall on the upper part and a supporting pile wall on the lower part (i.e., an upper and lower composite retaining structure with a balanced counterweight connected to the top of the cantilever retaining structure). By setting up an upper balanced counterweight support structure, a favorable gravity effect opposite to the adverse effect of the rock and soil pressure on the lower support structure is produced, thereby improving the overall stability and safety of the counterweight composite support structure to a certain extent. However, this counterweight composite support structure is essentially still a cantilever structure with only one embedded end and lack of redundant constraints. If the free cantilever section of the pile is too high, the pile will produce lateral deformation under the soil pressure. Excessive lateral deformation may even cause an engineering accident of pile breakage. In high-intensity areas, the greater the height of the cantilever structure, the more unfavorable its earthquake resistance is. Due to the particularity of geotechnical engineering, there is objective uncertainty in the deformation control and stability of this counterweight composite support structure.

[0003] Therefore, the key to solving the above problems is to research and develop a counterweight composite retaining wall and construction method with simple structure, multi-point constraints, overall structural stability, and adjustable prestress monitoring. Summary of the invention

[0004] The purpose of the present invention is to provide a prestressed load monitoring adjustable counterweight type combined retaining wall and a construction method.

[0005] The first object of the present invention is achieved as follows: the present invention comprises a counterweight type composite retaining wall body, a prestressed anchor cable, and a pressure sensor; a through hole is opened on the bottom plate of the balanced counterweight support structure of the counterweight type composite retaining wall body; the anchor head end of the prestressed anchor cable passes through the through hole and is fixed above the bottom plate of the balanced counterweight support structure by an anchor; the anchoring end of the prestressed anchor cable is arranged in a foundation drill hole; and the pressure sensor is arranged between the anchor and the bottom plate of the balanced counterweight support structure.

[0006] The second object of the present invention is achieved in this way. In the first step, the lower supporting pile wall and the balanced counterweight supporting structure bottom plate of the counterweight composite retaining wall are constructed, and when the concrete strength of the supporting pile wall and the balanced counterweight supporting structure bottom plate reaches the design requirements, the prestressed anchor cable with the anchor head pressure sensor is constructed;

[0007] The second step is to initially tension and lock the prestressed anchor cable when the mortar strength of the anchoring section of the prestressed anchor cable reaches the design requirements (the locking value is equal to the sum of the gravity of the anchor cable and the friction between the anchor cable and the side wall of the anchor hole);

[0008] The third step is to construct the remaining upper counterweight retaining structure and working well. When the concrete strength of the upper counterweight retaining structure and working well reaches the design requirements, backfill the earthwork behind the entire retaining structure to the design elevation;

[0009] The fourth step is to excavate the rock and soil in front of the counterweight composite retaining wall to the designed ground elevation, and at the same time monitor the change of the anchor cable tension value measured by the anchor head pressure sensor of the prestressed anchor cable, and determine the final locking value of the prestressed anchor cable according to the change of the anchor cable tension value and the stability required by the design;

[0010] The fifth step is to judge the stability of the entire counterweight composite retaining wall through real-time monitoring of the anchor head pressure sensor during the normal use of the counterweight composite retaining wall.

[0011] The present invention has the following technical effects:

[0012] Prestressed anchor cables are used to increase the force acting in the opposite direction to the lateral pressure of the soil on the counter-weight composite retaining structure, thereby improving the stability and safety of the counter-weight composite retaining structure, controlling the deformation of the entire retaining structure to a certain extent, and ensuring the overall stability of the retaining wall. At the same time, anchor cable head pressure sensors are used to monitor in real time the changes in anchor cable tension during the construction of the counter-weight composite retaining wall and the operation and use stages after completion, thereby judging the stability of the entire counter-weight composite retaining wall and making adjustments according to the situation to improve the stability and seismic resistance of the counter-weight composite retaining wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A structural schematic diagram of the present invention;

[0014] Figure 2 for Figure 1 Schematic diagram of top view;

[0015] Figure 3 A is a local enlarged schematic diagram;

[0016] Figure 4 Another structural schematic diagram of the present invention;

[0017] In the figure: 1-body of counterweight composite retaining wall, 101-bottom plate of balanced counterweight retaining structure, 102-through hole, 2-prestressed anchor cable, 201-anchor cable head, 3-pressure sensor, 4-anchor, 5-working well, 6-anchor pier, 7-original foundation, 8-backfill, 9-excavation design ground elevation. DETAILED DESCRIPTION

[0018] The present invention is further described below in conjunction with the accompanying drawings, but the present invention is not limited in any way. Any changes or substitutions made based on the teachings of the present invention belong to the protection scope of the present invention.

[0019] As attached Figure 1 The present invention shown in -4 includes a counterweight type composite retaining wall body 1, a prestressed anchor cable 2, and a pressure sensor 3. A through hole 102 is opened on the bottom plate 101 of the balanced counterweight support structure of the counterweight type composite retaining wall body. The anchor cable head end of the prestressed anchor cable 2 passes through the through hole 102 and is fixed above the bottom plate 101 of the balanced counterweight support structure through the anchor 4. The anchoring end of the prestressed anchor cable 2 is arranged in a foundation drill hole, and the pressure sensor 3 is arranged between the anchor 4 and the bottom plate 101 of the balanced counterweight support structure.

[0020] A working well 5 is provided between the bottom plate 101 of the counterweight support structure and the outside world. The pressure sensor 3 and the anchor 4 are located in the working well 5. The pressure sensor 3, the anchor 4 and the anchor cable head will not be exposed to the outside, which will affect the appearance and is also convenient for personnel to enter and exit to observe and adjust the prestress.

[0021] The opening above the working well 5 is provided with a manhole cover, and the height of the manhole cover is flush with the outer surface of the balancing weight support structure.

[0022] The prestressed anchor cable forms an angle θ with a vertical line of the bottom plate of the balance weight support structure.

[0023] The angle θ is 0-45 degrees.

[0024] The angle between the axis of the through hole and the vertical line of the bottom plate of the balance weight support structure is θ.

[0025] An anchor pier 6 is arranged between the pressure sensor 3 and the bottom plate 101 of the counterweight support structure. The angle formed by the upper and lower surfaces of the anchor pier 6 is the same as the angle θ between the prestressed anchor cable and the bottom plate of the counterweight support structure.

[0026] The anchor 4 is a repeatable tensioning anchor.

[0027] There are multiple prestressed anchor cables 2, and the multiple prestressed anchor cables 2 are arranged at intervals on the bottom plate 101 of the balance weight support structure.

[0028] The construction steps are:

[0029] The first step is to construct the lower supporting pile wall and the balanced counterweight supporting structure bottom plate of the counterweight composite retaining wall. When the concrete strength of the supporting pile wall and the balanced counterweight supporting structure bottom plate reaches the design requirements, the prestressed anchor cable with anchor head pressure sensor is constructed;

[0030] The second step is to initially tension and lock the prestressed anchor cable when the mortar strength of the anchoring section of the prestressed anchor cable reaches the design requirements (the locking value is equal to the sum of the gravity of the anchor cable and the friction between the anchor cable and the side wall of the anchor hole);

[0031] The third step is to construct the remaining upper counterweight retaining structure and working well. When the concrete strength of the upper counterweight retaining structure and working well reaches the design requirements, backfill the earthwork behind the entire retaining structure to the design elevation;

[0032] The fourth step is to excavate the rock and soil in front of the counterweight composite retaining wall to the designed ground elevation, and at the same time monitor the change of the anchor cable tension value measured by the anchor head pressure sensor of the prestressed anchor cable, and determine the final locking value of the prestressed anchor cable according to the change of the anchor cable tension value and the stability required by the design;

[0033] The fifth step is to judge the stability of the entire counterweight composite retaining wall through real-time monitoring of the anchor head pressure sensor during the normal use of the counterweight composite retaining wall.

[0034] The working principle and working process of the present invention: by real-time monitoring of the anchor cable tension changes of the pressure sensor, the stability state of the entire counterweight type composite retaining structure is intuitively reflected, and the prestressing force is adjusted according to the tension changes or other measures are taken to ensure the overall stability of the counterweight type composite retaining wall. During construction, the lower supporting pile wall and the balanced counterweight supporting structure bottom plate 101 of the counterweight type composite retaining wall body 1 are first constructed (for deeper backfill projects, the lower supporting pile wall is constructed first, and after the backfill is compacted and backfilled to the bottom elevation of the balanced counterweight supporting structure bottom plate 101 when the strength requirement is met, the balanced counterweight supporting structure bottom plate is constructed). After the concrete strength of the lower supporting pile wall and the balanced counterweight supporting structure bottom plate 101 reaches the design requirement, the prestressed anchor cable 2 with an anchor head pressure sensor is constructed. When the prestressed anchor After the mortar strength of the cable anchoring section reaches the design requirements, the prestressed anchor cable is initially tensioned and locked (the locking value is equal to the sum of the weight of the anchor cable and the friction between the anchor cable and the side wall of the anchor hole), and then the remaining upper counterweight support structure and the working well 5 are constructed. When the concrete strength of the upper counterweight support structure reaches the design requirements, the earthwork behind the counterweight composite retaining wall body 1 is backfilled to the design height, and the change of the anchor cable tension value measured by the anchor head pressure sensor 3 of the prestressed anchor cable is monitored and adjusted according to the requirements until the backfill reaches the design elevation. If the rock and soil in front of the counterweight composite retaining wall body needs to be excavated, the rock and soil in front is excavated to the design ground elevation 9, and the change of the anchor cable tension value measured by the anchor head pressure sensor 3 of the prestressed anchor cable is monitored, and the final locking value of the prestressed anchor cable is determined according to the change of the anchor cable tension value and the stability required by the design. During the normal use of the counterweight composite retaining wall, the stability of the entire counterweight composite retaining wall is judged by real-time monitoring of the anchor head pressure sensor 3.

Claims

1. A counterweight composite retaining wall with adjustable prestress monitoring, comprising a counterweight composite retaining wall body (1), a prestressed anchor cable (2), and a pressure sensor (3), characterized in that: A through hole (102) is provided on the bottom plate (101) of the counterweight support structure of the counterweight composite retaining wall body (1); the anchor cable head end of the prestressed anchor cable (2) passes through the through hole (102) and is fixed above the bottom plate (101) of the counterweight support structure by means of an anchor (4); the anchoring end of the prestressed anchor cable (2) is arranged in a foundation borehole; the pressure sensor (3) is arranged between the anchor (4) and the bottom plate (101) of the counterweight support structure; and an anchor pier (102) is provided between the pressure sensor (3) and the bottom plate (101) of the counterweight support structure. 6); a working well (5) is provided between the bottom plate (101) of the counterweight support structure and the outside world, and the pressure sensor (3) and the anchor (4) are located in the working well (5); the prestressed anchor cable (2) and a vertical line of the bottom plate (101) of the counterweight support structure form an angle θ, and the angle θ is 0 to 45 degrees; the angle formed by the upper and lower surfaces of the anchor pier (6) is the same as the angle θ between the prestressed anchor cable (2) and the bottom plate (101) of the counterweight support structure; the anchor (4) is a repeatable tensioning anchor cable, and the prestressed anchor cable (2) is a compensating tensioning prestressed anchor cable.

2. The prestressed load monitoring and adjustable counterweight composite retaining wall according to claim 1 is characterized in that: The upper opening of the working well (5) is provided with a well cover, and the height of the well cover is flush with the outer surface of the balancing weight support structure.

3. The prestressed load monitoring and adjustable counterweight composite retaining wall according to claim 1 is characterized in that: The angle between the axis of the through hole (102) and the vertical line of the balance weight support structure bottom plate (101) is θ.

4. The prestressed load monitoring and adjustable counterweight composite retaining wall according to claim 1 is characterized in that: There are a plurality of prestressed anchor cables (2), and the plurality of prestressed anchor cables (2) are arranged at intervals on the bottom plate (101) of the balancing counterweight support structure.

5. A construction method for the prestressed monitoring adjustable counterweight composite retaining wall according to claim 1, characterized in that: The steps include: The first step is to construct the lower support pile wall and the balanced counterweight support structure bottom plate (101) of the counterweight composite retaining wall, and when the concrete strength of the support pile wall and the balanced counterweight support structure bottom plate (101) reaches the design requirements, construct the prestressed anchor cable (2) with the anchor head pressure sensor; The second step is to initially tension and lock the prestressed anchor cable (2) when the mortar strength of the anchoring section of the prestressed anchor cable (2) reaches the design requirement, and the locking value is equal to the sum of the gravity of the anchor cable and the frictional resistance between the anchor cable and the side wall of the anchor hole; The third step is to construct the remaining upper counterweight retaining structure and the working well (5). When the concrete strength of the upper counterweight retaining structure and the working well (5) reaches the design requirements, the earthwork behind the entire retaining structure is backfilled to the design elevation; The fourth step is to excavate the rock mass in front of the counterweight composite retaining wall to the designed ground elevation, while monitoring the change in the anchor cable tension value measured by the anchor head pressure sensor of the prestressed anchor cable (2), and determine the final locking value of the prestressed anchor cable according to the change in the anchor cable tension value and the stability required to be achieved in the design; The fifth step is to judge the stability of the entire counterweight composite retaining wall through real-time monitoring of the anchor head pressure sensor during the normal use of the counterweight composite retaining wall.

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