Water pumping steel pipe, underground diaphragm wall groove wall stable construction system and construction method

Abstract

The invention discloses a water pumping steel pipe, an underground diaphragm wall groove wall stable construction system and a construction method.The novel water pumping steel pipe is formed by connecting an inner-layer steel pipe, an outer-layer steel pipe, a top steel plate, a bottom steel plate and a plurality of steel plates, the steel plates are arranged between the pipe walls in the pipe length direction, water inlet holes can be formed in the outer pipe wall at the designated position, and water filtering holes are formed in the inner pipe wall; the novel water pumping steel pipes in rows are embedded in the two sides of the groove wall, the drilling step of conventional underground water pumping pipe arrangement is not needed, the steel pipes interact with the soil body, the horizontal lateral movement of the soil body can be limited through the soil arching effect, the groove wall of the underground diaphragm wall is stabilized from the outer side, and the water pumping effect of the underground diaphragm wall is improved. For the position where a weak soil layer is located, water pumping operation is conducted through the water pumping steel pipe, formation of mud cakes in the groove wall of the area is accelerated, the mud wall protection effect is improved, the groove wall of the underground diaphragm wall is stabilized from the inner side, meanwhile, the pressed-in water pumping steel pipe can be pulled out for cyclic utilization, and the construction cost is reduced.

Description

Technical Field

[0001] The invention patent relates to the technical field of underground continuous wall construction, and in particular to a pumping steel pipe, underground continuous wall trench wall stabilization construction system and construction method. Background Art

[0002] In the process of urban underground space development and deep foundation pit excavation, underground continuous wall is widely used in deep foundation pit engineering as an important supporting structure. However, it is easy to collapse during the trenching process of underground continuous wall. The main reasons are as follows: after trenching, the overload caused by the engineering equipment on the soil outside the trench wall, coupled with the soil side pressure and the influence of groundwater, causes the soil to move horizontally to the inside of the trench wall; the wall protection mud cannot form a good mud skin on the inner side wall of the trench wall in time, so it cannot play an effective liquid support role; the trench is left for too long after trenching, and the mud sedimentation and wall protection effect in the trench wall is weakened. Especially in soft soil, saturated clay or sandy soil areas, the stability of the trench wall itself is poor, and trench wall collapse accidents occur from time to time, which will not only delay the construction period, but also may cause serious economic losses and safety hazards.

[0003] Therefore, underground continuous wall trench wall stabilization technology is a vital part of deep foundation pit engineering. In order to deal with the above problems, the common stabilization technical ideas in current projects can be roughly divided into two categories: stabilization from the inside of the trench wall, mainly mud wall protection, etc.; stabilization from the outside of the trench wall, such as longitudinal grouting around the trench wall before grooving, cement soil mixing piles and other foundation treatments. These methods often have high construction costs or unstable quality. Summary of the invention

[0004] In order to overcome the technical defects of the prior art, the present invention provides a water pumping steel pipe, including an inner pipe and an outer pipe, the outer pipe is sleeved on the outside of the inner pipe and both ends are provided with annular steel plates to connect the two ends of the inner pipe and the outer pipe to achieve sealing between the inner pipe and the outer pipe, the bottom end of the outer pipe is also provided with annular steel plates, the inner pipe wall is evenly provided with water filtering holes, the outer pipe wall is evenly provided with water inlet holes, and a filter is also provided between the inner pipe and the outer pipe.

[0005] A V-shaped baffle is provided on the outer side of the water inlet hole, the center of the V-shaped baffle corresponds to the center of the water inlet hole one by one, and the orthographic projection of the V-shaped baffle on the wall of the outer tube covers the water inlet hole.

[0006] The top tube wall of the outer tube is evenly and vertically provided with trapezoidal steel plates, and the trapezoidal steel plates are provided with reserved holes.

[0007] Circular steel plates are evenly and equidistantly arranged between the inner tube and the outer tube along the tube length direction.

[0008] The water filtering holes are evenly staggered on the wall of the inner tube, and the water inlet holes are arranged in an array and in parallel on the wall of the outer tube.

[0009] An underground continuous wall trench wall stabilization construction system, comprising: The groundwater recharge module is used to monitor the groundwater level. When the water level is lower than the threshold, the groundwater is recharged to maintain the groundwater level. The mud replenishment module in the trench is used to monitor the mud level in the underground continuous wall trench section. When the liquid level is lower than the warning threshold, the mud is replenished in the underground continuous wall trench section to reach the preset mud liquid level. An underground continuous wall trench section, with multiple pumping steel pipes inserted on both sides of the underground continuous wall trench section, the pumping steel pipes on the same side are arranged equidistantly and are all connected to the water collecting pipe and connected to the water inlet pool through a pumping pump for extracting groundwater.

[0010] The groundwater recharge module includes multiple observation wells, multiple recharge wells, an intelligent control system and a clear water tank. The observation wells and the recharge wells are both inserted into the ground and penetrate into the groundwater layer. A water level monitoring sensor is provided in the observation well for collecting and monitoring groundwater level signals and transmitting them to the intelligent control system. The clear water tank is connected to a diverter through a pipeline, a water pump is provided on the pipeline, and the diverters are respectively connected to the recharge wells.

[0011] The mud replenishment module in the groove includes a mud pool and the intelligent control system. The mud pool is connected to the mud pump through a pipeline, and the mud pump is connected to the underground continuous wall groove section through a pipeline. A liquid level sensor is provided in the underground continuous wall groove section for collecting the mud liquid level signal in the underground continuous wall groove section and transmitting it to the intelligent control system.

[0012] A method for stabilizing the wall of an underground continuous wall trench comprises the following steps: S1: Before the underground continuous wall trench section is formed, the positioning points are measured and placed along the wall on both sides, and rows of positioning frames are installed. Rows of pumping steel pipes are directly pressed into the soil from both ends to the middle. When the steel pipes are sunk to 1m above the positioning frames, the positioning frames are removed and the steel pipes are sunk to the designed position. The water collecting pipes are laid on the ground, connected to the top of the pumping steel pipes, and the water pumps are installed; S2: During the underground continuous wall trenching construction phase, the pumping steel pipes that have been sunk will start pumping water synchronously for the target weak soil layer. During the entire construction phase, the slurry level changes in the trench section will be monitored in real time. At the same time, the water level changes in the site will be monitored through the observation well. The monitoring data will be synchronously fed back to the intelligent control system. According to the monitoring results, grouting and groundwater recharge will be carried out in a timely manner; S3: After the construction of the underground continuous wall of this trench section is completed, the pumping steel pipes are pulled out one by one starting from one end of the row of pumping steel pipes, and recycled for the stabilization construction of the underground continuous wall of other trench sections to achieve recycling.

[0013] In step S2, a liquid level sensor is set at the end of the underground continuous trench section to monitor the mud level in the trench section in real time, and the data is transmitted to the on-site intelligent control system. When the mud level is lower than the warning height, the intelligent control system controls the mud pump to extract mud from the mud pool and replenish mud through the connected pipeline to meet the mud level requirement.

[0014] The beneficial effects of the present invention are: 1. The present invention can work together from the inside and outside of the trench wall to restrict the lateral movement of the soil at the trench wall and stabilize the trench wall.

[0015] 2. The pumping position of the pumping steel pipe in the present invention can be arranged according to demand, and pumping operations can be carried out on weak soil layers to accelerate the formation of mud skin in the trench wall in this area, improve the effect of mud wall protection, and stabilize the underground continuous wall trench wall from the inside.

[0016] 3. In the present invention, the pumping steel pipe is directly pressed into the buried pipe without drilling holes, thereby enhancing the "soil arch effect" and limiting the horizontal lateral movement of the soil from the outside of the trench wall. The construction process is simple and time-consuming.

[0017] 4. The buried water pumping steel pipes in the present invention can be pulled out and recycled, thus reducing the construction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of water pumping through a water pumping steel pipe of the present invention; Figure 2 It is a cross-sectional view and a top view of the end of the water pumping steel pipe of the present invention; Figure 3 This is a detailed schematic diagram of the water pumping part of the water pumping steel pipe of the present invention; Figure 4 It is a schematic diagram of the plan layout of the pumping steel pipe of the present invention and the method for stabilizing the underground continuous wall trench wall thereof; Names marked in the figure: underground continuous wall trench section 1, pumping steel pipe 2, inner pipe 201, outer pipe 202, bottom circular steel plate 203, circular steel plate 204, trapezoidal steel plate 205, reserved holes 206, water filter holes 207, filter screen 208, water inlet hole 209, V-shaped baffle 210, water collecting pipe 3, pumping pump 4, water inlet pool 5, observation well 6, recharge well 7, water injection pipe 8, diverter 9, water pump 10, clean water pool 11, mud pump 12, mud pool 13, intelligent control system 14. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and embodiments. The embodiments are only used to explain the present invention and are not used to limit the scope of the present invention. It should be noted that the drawings are simplified and use non-precise proportions, which are only used to facilitate and clearly assist in explaining the embodiments of the present invention. like Figure 1-4 As shown, in this example, the trench wall stabilization construction is carried out simultaneously inside and outside the underground continuous wall trench section. Before the construction of the underground continuous wall trench section, 13 20m long pumping steel pipes 2 are inserted along the wall at a distance of 0.5m at a distance of 1.0m from both sides of the trench section. The rows of steel pipes interact with the soil, and the soil between the steel pipes produces a "soil arch effect", which together with the steel pipes restricts the soil from horizontally moving toward the trench wall.

[0020] The pumping steel pipe 2 is a double-layer steel pipe. The outer steel pipe 202 is a seamless steel pipe with an outer diameter of 152mm and a wall thickness of 4.5mm, and the inner steel pipe 201 is a seamless steel pipe with an outer diameter of 127mm and a wall thickness of 4mm. The bottom of the pumping steel pipe is welded and fully sealed with a 5mm thick circular steel plate 203 with a diameter of 152mm, and the top is welded and sealed between the double-layer pipe walls with a 5mm thick, inner diameter of 123mm, and outer diameter of 152mm circular steel plate 204. Between the pipe walls of the inner and outer steel pipes, a 5mm thick circular steel plate 204 is evenly welded every 2.0m along the pipe length direction to play a supporting and reinforcing role between the pipe walls.

[0021] According to the distribution of weak soil layers in the project, the drilling positions of the water filter holes 207 and the water inlet 209 of the pumping steel pipe are determined. The water filter holes 207 and the water inlet holes 209 are opened at 14.5m~15.5m of the double-layer steel pipe. The water filter holes 207 on the inner pipe wall are arranged in a plum blossom shape, with a hole diameter of 15mm and a hole center spacing of about 40mm. The water inlet holes 209 on the outer pipe wall are arranged in an aligned shape, with a hole diameter of 50mm and a hole center spacing of about 120mm. A V-shaped baffle plate 210 is set on each outer pipe water inlet hole. The V-shaped baffle plate 210 corresponds to the position of the water inlet hole 209 one by one. The projection size of the V-shaped baffle plate 210 on the plane of the water inlet hole 209 is 70mm×70mm. The normal direction of the V-shaped opening surface formed by the V-shaped baffle plate 210 is perpendicular to the pipe length direction to prevent the water inlet hole 209 from being blocked by the soil. When the pumping operation begins, the mud in the weak soil layer area of ​​the trough wall where the water filter hole 207 is located will flow unidirectionally to the soil on both sides of the trough wall, which promotes the accelerated formation of the mud skin attached to the trough wall, strengthens the adsorption force between the mud skin and the trough wall, and improves the wall protection effect of the mud.

[0022] The new type of pumping steel pipe has four trapezoidal steel plates 205 with reserved holes 206 in the center vertically symmetrically welded on the outer side of the pipe wall 50mm away from the top of the pumping steel pipe. The trapezoidal steel plate 205 is 5mm thick and 30mm high, with a bottom side length of 80mm and a top side length of 50mm. The diameter of the center circular hole 206 is 15mm, which is used to pass the steel hinge wire and assist in the construction of pulling out the steel pipe.

[0023] The top of the pumping steel pipe 2 is connected to the water collecting pipe 3 by a hose. The outside of the water collecting pipe 3 is provided with an interface to connect with the water pump 4 through a pumping pipe, and the groundwater extracted by the pumping pump is discharged into the water inlet pool 5.

[0024] A bracket is installed at the end of the underground continuous wall trench section 1, and a liquid level detector is placed to monitor the mud level in the trench section in real time. The monitoring data is fed back to the intelligent control system 14. When the liquid level is lower than the warning elevation, the mud pump 12 is turned on to replenish the mud in the trench in time, and the mud pump 12 is turned off after reaching the required height.

[0025] Recharge construction measures: 5m outside both sides of the underground continuous wall groove section 1, along the direction of the underground continuous wall, set up observation wells 6 with a spacing of 10m. The observation wells 6 are equipped with liquid level detectors to monitor the groundwater level in real time and transmit the data to the intelligent control system 14. 8m outside both sides of the underground continuous wall groove section 1, along the direction of the underground continuous wall, set up recharge wells 7 with a spacing of 6m to insert injection pipes 8. The injection pipes 8 are uniformly connected to the water pumps 10 through the diverter 9. When the groundwater level monitoring data value received by the intelligent control system 14 is lower than the warning value, the water pump 10 is immediately controlled to extract clean water from the clean water tank 11, and inject it into the recharge well 7 through the diverter 9 injection pipe 8 to maintain the original groundwater level unchanged.

[0026] The present invention proposes a method for stabilizing the wall of an underground continuous wall trench, comprising the following steps: S1: Before the underground continuous wall trench section 1 is formed, the positioning points are measured and placed along the wall on both sides, and rows of positioning frames are installed. Rows of pumping steel pipes 2 are directly pressed into the soil from both ends to the middle. When the steel pipe sinking construction reaches 1m above the positioning frame, the positioning frame is removed and the steel pipe sinking construction is completed by pressing it to the designed position. The water collecting pipe 3 is laid on the ground, and the water collecting pipe 3 is connected to the top of the pumping steel pipe 2, and the water pump 4 is installed; S2: During the underground continuous wall trenching construction phase, the pumping steel pipe 2 that has been sunk starts pumping water synchronously for the target weak soil layer, and the slurry level changes in the trench section are monitored in real time during the entire construction phase. At the same time, the water level changes in the site are monitored through the observation well 6. The monitoring data is synchronously fed back to the intelligent control system 14, and grouting and groundwater recharging are carried out in a timely manner according to the monitoring results; S3: After the construction of the underground continuous wall of the trench section is completed, the pumping steel pipes 2 are pulled out one by one starting from one end of the row of pumping steel pipes 2, and are recycled for the stabilization construction of the underground continuous wall of other trench sections to achieve recycling.

[0027] Before the underground continuous wall trench section is formed, the pumping steel pipe 2 is uniformly pressed into the wall direction on both sides. After the underground continuous wall trench section is constructed, the pumping steel pipe 2 interacts with the soil, and the soil between the pumping steel pipes 2 produces a "soil arch effect", which together with the pumping steel pipe 2 restricts the soil from horizontally moving toward the trench wall. At the same time, the pumping operation is started in the target weak soil layer through the pumping steel pipe 2. The pumping operation causes the slurry in the trench wall of the soil layer area to flow unidirectionally to the soil on both sides of the trench wall, promotes the accelerated formation of the mud skin attached to the trench wall, enhances the adsorption force between the mud skin and the trench wall, and improves the wall protection effect of the mud. Since there is a pumping operation in this construction method, the changes in the mud level in the trench section and the water level of the observation well in the site are monitored during the construction process, and synchronously fed back to the intelligent control system 14, so that the mud in the trench section is replenished in time, and the groundwater recharge construction is carried out in the site to maintain the mud level in the trench section and the groundwater level in the site basically unchanged. Finally, after the construction of the underground continuous wall of this trench section is completed, the pumping steel pipe is pulled out and recycled for use in the stabilization construction of the underground continuous wall of other trench sections, thus achieving recycling.

[0028] The present invention buries rows of new pumping steel pipes 2 on both sides of the trench wall, eliminating the need for drilling steps for conventional underground pumping pipe arrangements. The steel pipes interact with the soil, and the "soil arch effect" can be used to limit the horizontal lateral movement of the soil, thereby stabilizing the underground continuous wall trench wall from the outside. For locations where weak soil layers are located, pumping operations are performed through the pumping steel pipes 2 to accelerate the formation of mud skin in the trench wall in this area, improve the effect of mud wall protection, and stabilize the underground continuous wall trench wall from the inside. At the same time, the pressed-in pumping steel pipes 2 can be pulled out for recycling, reducing construction costs.

[0029] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A water pumping steel pipe, characterized in that: The invention comprises an inner tube (201) and an outer tube (202), wherein the outer tube (202) is sleeved on the outer side of the inner tube (201) and is provided with annular steel plates (204) at both ends to connect the two ends of the inner tube (201) and the outer tube (202) so as to achieve sealing between the inner tube (201) and the outer tube (202), and the bottom end of the outer tube (202) is also provided with annular steel plates (204), the inner tube (201) is provided with water filtering holes (207) evenly distributed on the tube wall, the outer tube (202) is provided with water inlet holes (209) evenly distributed on the tube wall, and a filter screen (208) is also provided between the inner tube (201) and the outer tube (202).

2. A water pumping steel pipe according to claim 1, characterized in that: A V-shaped shielding plate (210) is provided on the outside of each water inlet hole (209), the center of each V-shaped shielding plate (210) corresponds one-to-one to the center of each water inlet hole (209), and the orthographic projection of each V-shaped shielding plate (210) on the wall of the outer tube (202) covers the water inlet hole (209).

3. A water pumping steel pipe according to claim 1, characterized in that: Trapezoidal steel plates (205) are evenly and vertically arranged outside the tube wall at the top of the outer tube (202), and reserved holes (206) are provided on the trapezoidal steel plates (205).

4. A water pumping steel pipe according to claim 1, characterized in that: Circular steel plates (204) are evenly and equidistantly arranged between the inner tube (201) and the outer tube (202) along the tube length direction.

5. A water pumping steel pipe according to claim 1, characterized in that: The water filtering holes (207) are evenly staggeredly arranged on the wall of the inner tube (201), and the water inlet holes (209) are arranged in parallel in an array on the wall of the outer tube (202).

6. An underground continuous wall trench wall stabilization construction system, comprising a pumping steel pipe (2) as claimed in any one of claims 1 to 5, characterized in that: Also includes: The groundwater recharge module is used to monitor the groundwater level. When the water level is lower than the threshold, the groundwater is recharged to maintain the groundwater level. The mud replenishment module in the trench is used to monitor the mud level in the underground continuous wall trench section. When the liquid level is lower than the warning threshold, the mud is replenished in the underground continuous wall trench section to reach the preset mud liquid level. An underground continuous wall trench section (1), wherein a plurality of pumping steel pipes (2) are inserted into both sides of the underground continuous wall trench section (1), and the pumping steel pipes (2) on the same side are arranged at equal intervals and are all connected to a water collecting pipe (3) and are connected to a water inlet pool (5) via a pumping pump (4) for extracting groundwater.

7. The underground continuous wall trench wall stabilization construction system according to claim 6, characterized in that: The groundwater recharge module comprises a plurality of observation wells (6), a plurality of recharge wells (7), an intelligent control system (14) and a clear water tank (11); the observation wells (6) and the recharge wells (7) are both inserted into the ground and penetrate into the groundwater layer; a water level monitoring sensor is provided in the observation well (6) for collecting and monitoring groundwater level signals and transmitting them to the intelligent control system (14); the clear water tank (11) is connected to a flow divider (9) via a pipeline; a water pump (10) is provided on the pipeline; and the flow dividers (9) are respectively connected to the recharge wells (7).

8. The underground continuous wall trench wall stabilization construction system according to claim 6, characterized in that: The in-tank mud replenishment module comprises a mud pool (13) and the intelligent control system (14); the mud pool (13) is connected to a mud pump (12) via a pipeline; the mud pump (12) is connected to the underground continuous wall trench section (1) via a pipeline; a liquid level sensor is provided in the underground continuous wall trench section (1) for collecting mud liquid level signals in the underground continuous wall trench section (1) and transmitting the signals to the intelligent control system (14).

9. A method for stabilizing the wall of an underground continuous wall trench, characterized in that: The specific steps include: S1: Before the underground continuous wall trench section (1) is formed, positioning points are measured and placed along the wall on both sides, and rows of positioning frames are installed. Rows of pumping steel pipes (2) are directly pressed into the soil from both ends to the middle in sequence. When the steel pipes are sunk to 1m above the positioning frames, the positioning frames are removed and the steel pipes are sunk to the designed position. A water collecting pipe (3) is laid on the ground, and the water collecting pipe (3) is connected to the top of the pumping steel pipe (2). A water pump (4) is installed. S2: During the underground continuous wall trenching construction phase, the pumping steel pipe (2) that has been installed starts pumping water synchronously with the target weak soil layer. During the entire construction phase, the slurry level changes in the trench section are monitored in real time. At the same time, the water level changes in the site are monitored through the observation well (6). The monitoring data is synchronously fed back to the intelligent control system (14). Based on the monitoring results, grouting and groundwater recharging are carried out in a timely manner. S3: After the construction of the underground continuous wall of the trench section is completed, the pumping steel pipes (2) are pulled out in sequence starting from one end of the row of pumping steel pipes (2) and recycled for use in the trench wall stabilization construction of the underground continuous wall of other trench sections, thereby achieving recycling.

10. The underground continuous wall trench wall stabilization construction method according to claim 9, characterized in that: In step S2, a liquid level sensor is provided at the end of the underground continuous trench section to monitor the position of the mud liquid level in the trench section in real time, and the data is transmitted to the on-site intelligent control system (14). When the mud liquid level is lower than the warning height, the intelligent control system (14) controls the mud pump (12) to extract mud from the mud pool (13), and replenishes mud through the connected pipeline to meet the mud liquid level requirement.

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