A grouting machine for foundation pit in water-rich sand and gravel stratum with controllable slurry penetration pressure and a sealing and water-stopping method

Abstract

The present invention relates to the technical field of foundation pit grouting machines, and specifically to a foundation pit grouting machine for water-rich sand and gravel formations with controllable slurry penetration pressure and a sealing and water-stopping method. The auxiliary frame arranged on the grouting machine body can retract and extend the guide tube, and the grouting pressure can be adjusted and switched by an electric hammer and a propulsion mechanism. The grouting pressure of the grouting machine is adjusted to ensure the penetration pressure of the slurry in the water-rich sand and gravel formations and avoid the occurrence of grouting hollow areas.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit grouting machines, and in particular to a foundation pit grouting machine for water-rich sand and gravel formations with controllable slurry penetration pressure and a sealing and water-stopping method. Background Art

[0002] The anti-seepage design of water-rich sand and gravel strata is more common in water conservancy projects. When excavating the foundation pit of hydraulic structures, the dewatering and water-stopping problems of the pebble layer must be considered. The water-adjacent sand and gravel strata have large particle size, strong permeability, and high water content. On the one hand, it increases the construction difficulty of foundation pit dewatering. On the other hand, when the foundation pit is excavated or the hydraulic structure is used normally, there will be risks of seepage damage such as water and sand gushing, which will cause local degassing and settlement and cause engineering quality accidents. When the existing foundation pit of water-rich sand and gravel stratum is excavated, a water-stop curtain is usually made on the periphery of the foundation pit. The water-stop curtain usually adopts high-pressure rotary jet curtain grouting or concrete anti-seepage wall. However, when using high-pressure rotary jet curtain grouting, the high-pressure nozzle overcomes the formation resistance and the rotation torque is too large, which limits the grouting depth, and the drilling spacing cannot be greater than 60cm. The project volume is large, and the groundwater seepage in the water-rich sand and gravel stratum will cause slurry loss, which makes the construction difficult. The use of concrete anti-seepage wall requires mud wall impact to form a groove, which is very likely to leak slurry and cause the groove wall to collapse.

[0003] In the process of consolidation grouting of water-rich sand and gravel formations, it is necessary to use a grouting machine to carry out grouting of drilled holes. The grouting machine is a volumetric pump that completes the liquid transportation by changing the closed volume. The existing grouting machine generally includes a power device for providing pressure and a barrel for storing slurry. However, when the existing grouting machine is used for grouting water-rich sand and gravel formations, although the slurry can be pressure-injected by the power device, the penetration pressure of the slurry in the water-rich sand and gravel formation cannot be guaranteed, which will cause the slurry to have poor penetration effect or even no penetration, thereby causing hollow areas to appear in the grouting of the foundation pit of the water-rich sand and gravel formation, and the consolidation grouting of the foundation pit cannot be effectively achieved. Summary of the Invention

[0004] In response to the above-mentioned defects and problems, the present invention provides a foundation pit grouting machine for water-rich sand and gravel formations with controllable slurry penetration pressure and a closed water-stopping method. The purpose is to adjust and switch the grouting pressure through an impact drive mechanism and a propulsion mechanism, adjust the grouting pressure of the grouting machine, ensure the penetration pressure of the slurry in the water-rich sand and gravel formation, and avoid the occurrence of grouting hollow areas.

[0005] The solution adopted by the present invention to solve its technical problem is: a grouting machine for a water-rich sand and gravel formation foundation pit with controllable slurry penetration pressure and a closed water-stopping method, comprising a grouting machine main body, an auxiliary frame installed on the grouting machine main body, a guide tube matched with a sleeve at the free end of the auxiliary frame, and a telescopic member for controlling the retraction and extension of the guide tube on the auxiliary frame, a grouting tube arranged in the guide tube, and a sealing assembly arranged at the bottom of the grouting tube, a cross-shaped four-way pipe arranged above the guide tube, a control cylinder connected above the cross-shaped four-way pipe, and the interior of the cross-shaped four-way pipe is divided into A slurry inlet chamber, a slurry outlet chamber, a punching chamber and a cache chamber, a piston matching set in the punching chamber, and an impact drive mechanism for controlling the high-frequency vibration impact of the piston is provided in the control cylinder, and a propulsion mechanism for moving the impact drive mechanism is also provided inside the control cylinder, and a cache yielding component is also provided in the cache chamber. The propulsion mechanism can drive the piston when controlling the movement of the impact drive mechanism. When the piston moves between the punching chamber and the slurry outlet chamber, the impact drive mechanism can control the piston to achieve high-frequency vibration impact, increase the grouting pressure, and improve the penetration pressure of the slurry.

[0006] Furthermore, the auxiliary frame includes an articulated rod arranged in parallel above and below, one end of the articulated rod is hinged to the column of the grouting machine body, and the other end is hinged to the guide tube. The telescopic part is a hydraulic cylinder, and the two ends of the hydraulic cylinder are respectively hinged to the column and the guide tube.

[0007] Furthermore, the right side of the interior of the cross-shaped four-way pipe is the pulp inlet chamber, the left side of the interior is the buffer chamber, the upper side of the interior is the punching chamber, and the lower side of the interior is the pulp outlet chamber.

[0008] Furthermore, the impact driving mechanism is an electric hammer, the output end of the electric hammer is fixedly connected to the piston, and the electric hammer can control the piston to achieve high-frequency vibration impact.

[0009] Furthermore, the propulsion mechanism is an electric push rod, which is fixed in the control cylinder, and the output end of the electric push rod is fixedly connected to the tail of the electric hammer. The electric push rod controls the movement of the electric hammer to vertically adjust the position of the piston, move the piston between the punching chamber and the pulp outlet chamber, and seal the pulp inlet chamber.

[0010] Furthermore, the cache yield assembly includes a pressure spring arranged in the cache chamber, and the front end of the pressure spring is connected to a sealing slide.

[0011] Furthermore, it also includes an auxiliary sealing component for auxiliary sealing of the grouting hole.

[0012] Furthermore, a sealing and water-stopping method applied to a grouting machine is characterized by comprising the following steps: S1: adopting a large slope and mesh spraying method around the foundation pit, laying out lines on the unexcavated foundation pit according to the construction drawings to determine the positions of the grouting holes, and marking them, setting the spacing between adjacent grouting holes to 2.5m or 3m, and sorting the grouting holes;

[0013] S2: Use a hydraulic rotary drill and follow-through drilling to drill grouting holes according to the designed final hole depth. The deviation of the grouting hole azimuth angle should not exceed 5 degrees, and the deviation of the top angle should not exceed 2 degrees. After the drilling is completed, the hole is flushed to openly flush the residual rock powder in the hole.

[0014] S3: Water pressure test: a water pressure test is conducted on the grouting holes using the single-point method. Under stable pressure, the pressure flow rate is measured every 5 minutes. The water pressure test is terminated if the difference between the maximum and minimum values ​​of four consecutive readings is less than 10% of the final value or the difference between the maximum and minimum values ​​of four consecutive readings is less than 1L / min.

[0015] S4: Align the grouting pipe of the grouting machine with the grouting hole and block the grouting hole. The grouting machine performs controlled grouting within the designed stratum thickness range. The grouting adopts the full-hole section one-time pure pressure method to consolidate the water-rich sand and gravel strata on the surrounding foundation pit slopes and the bottom of the foundation pit. The consolidation grouting depth is based on the pressure weight principle, and the consolidation thickness of the pressure cap is greater than the external water penetration pressure.

[0016] S5: After the consolidation grouting is completed, the grouting holes are sealed by mechanical grouting with a slurry with a water-cement ratio of 0.5:1;

[0017] S6: After the consolidation grouting of the foundation pit is completed, the foundation pit is excavated using an excavator and a soil transport vehicle.

[0018] The beneficial effects of the present invention are as follows: the present invention has a unique structure and an ingenious design. The auxiliary frame on the main body of the grouting machine controls the guide tube, and the retraction and extension of the guide tube are controlled by the telescopic part. A grouting tube is arranged in the guide tube, and a cross-shaped four-way tube is connected above the guide tube. The interior of the cross-shaped four-way tube is divided into a slurry inlet chamber, a slurry outlet chamber, a punching chamber and a buffer chamber. The propulsion mechanism controls the impact driving mechanism to move and can drive the piston. When the piston moves between the punching chamber and the slurry outlet chamber, the impact driving mechanism is started to control the piston to achieve high-frequency vibration impact, increase the grouting pressure in the grouting tube, and utilize the high-frequency vibration impact force to increase the penetration pressure of the slurry in the formation, so that the slurry can fully penetrate and perform consolidation grouting on the foundation pit of the water-rich sand and gravel formation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is one of the overall structural diagrams of the present invention.

[0020] Figure 2 A schematic diagram of the auxiliary rack structure.

[0021] Figure 3 for Figure 2 exploded view.

[0022] Figure 4 Schematic diagram of the internal structure of a cross-shaped four-way pipe.

[0023] Figure 5 This is one of the structural diagrams of the auxiliary sealing component.

[0024] Figure 6 This is the second schematic diagram of the auxiliary sealing component structure.

[0025] In the figure: 1-grouting machine body, 2-auxiliary frame, 201-hinge rod, 202-hydraulic cylinder, 203-support ear, 3-cross-shaped four-way pipe, 301-slurry inlet chamber, 302-slurry outlet chamber, 303-punching chamber, 304-cache chamber, 4-guide tube, 5-grouting pipe, 6-sealing ring, 7-electric hammer, 8-electric push rod, 9-cache assembly, 901-pressure spring, 902-sealing slide plate, 10-control cylinder, 11-locking wire, 12-piston, 13-annular airbag, 14-docking I-spool, 15-sealing sleeve roller, 16-oblique locking plate, 17-matching snap ring. DETAILED DESCRIPTION

[0026] The present invention will be further described below with reference to the accompanying drawings and examples.

[0027] Example 1: When consolidating grouting is carried out on the foundation pit of water-rich sand and gravel formation, it is necessary to use a grouting machine to drill holes and grouting to allow the slurry to enter the formation. The grouting machine is a volumetric pump that completes the liquid transportation by changing the closed volume. The existing grouting machine generally includes a power device for providing pressure and a barrel for storing slurry. However, when the existing grouting machine is grouting the water-rich sand and gravel formation, although the slurry can be pressure-injected by the power device, the penetration pressure of the slurry in the water-rich sand and gravel formation cannot be guaranteed, which will cause the slurry to have poor penetration effect or even no penetration, and then cause the grouting of the foundation pit of the water-rich sand and gravel formation to have a hollow area, and the consolidation grouting of the foundation pit cannot be effectively achieved, and there are certain defects.

[0028] In view of the above problems, this embodiment provides a grouting machine for a foundation pit in a water-rich sand and gravel formation with controllable slurry penetration pressure and a sealing and water-stopping method, such as Figure 1-3 As shown, it includes a grouting machine body 1, a column is vertically fixed on the grouting machine body 1, and an auxiliary frame 2 is installed on the grouting machine body 1 through the column. The auxiliary frame 2 includes a hinged rod 201 arranged in parallel with each other, one end of the hinged rod 201 is hinged to the column through a support ear, and the other end of the hinged rod 201 is hinged to the guide tube 4 through the support ear. A parallel four-bar structure is formed between the column, the hinged rod 201 and the guide tube 4, and a hydraulic cylinder 202 is hinged between the guide tube 4 and the column. The tail end of the hydraulic cylinder 202 is hinged to the column, and the output end is hinged to the guide tube 4. When the output end of the hydraulic cylinder 202 is extended and retracted, under the action of the parallel four-bar structure, it can control the retraction and extension of the guide tube 4, so that the guide tube 4 is expanded outward or retracted inward;

[0029] A matching sleeve is provided in the guide tube 4 with a grouting pipe 5, and a locking wire 11 for locking the grouting pipe 5 is installed on the side of the guide tube 4. The grouting pipe 5 can move in the guide tube 4, and the position of the grouting pipe 5 can be adjusted. The grouting pipe 5 can be locked by the locking wire 11. A sealing ring 6 is provided at the bottom of the grouting pipe 5 to seal the grouting hole. The cross-shaped four-way pipe 3 is provided above the guide tube 4, and the cross-shaped four-way pipe 30 is connected to the guide tube 4, and a control cylinder 10 is fixed above the cross-shaped four-way pipe 3. Figure 4 As shown, the right side of the interior of the cross-shaped four-way pipe 3 is the slurry feeding chamber 301, the left side of the interior is the buffer chamber 304, the upper side of the interior is the punching chamber 303, and the lower side of the interior is the slurry discharging chamber 302. The slurry discharging chamber 302 is connected to the grouting pipe 5, and a piston 12 is matched with the punching chamber, and an electric hammer 7 is provided in the control cylinder 10. The output end of the electric hammer 7 is fixedly connected to the piston 12. The electric hammer 7 can control the high-frequency vibration impact of the piston 12, and an electric push rod 8 is fixedly installed in the control cylinder 10. The output end of the electric push rod 8 is fixedly connected to the tail of the electric hammer 7. The electric push rod 8 controls the movement of the electric hammer 7 to vertically adjust the position of the piston 12, and moves the piston 12 between the punching chamber 303 and the slurry discharging chamber 302 to block the slurry feeding chamber 301. After the slurry feeding chamber 301 is blocked, the slurry cannot pass through the slurry feeding chamber into the slurry discharging chamber and be discharged;

[0030] A cache giving way component is provided in the cache chamber 304, and the cache giving way component includes a pressure spring 901 connected transversely in the cache chamber, and a sealing slide 902 is connected to the front end of the pressure spring 901. The sealing slide 902 can slide in the cache chamber 304. When the piston 12 moves between the punching chamber 303 and the slurry discharge chamber 302, part of the slurry will be squeezed into the cache chamber 304, and the sealing slide 902 squeezes the pressure spring 901 to give way to the slurry.

[0031] When the piston 12 moves to between the punching chamber 303 and the slurry discharge chamber 302, the electric hammer 7 is started to control the piston 12 to achieve high-frequency vibration impact, thereby increasing the grouting pressure in the grouting pipe 5. The high-frequency vibration impact force is used to increase the penetration pressure of the slurry in the formation, so that the slurry can fully penetrate and perform consolidation grouting on the foundation pit of the water-rich sand and gravel formation;

[0032] When grouting the foundation pit of the water-rich sand and gravel stratum, the grouting machine body is moved to the grouting hole, and the auxiliary frame is adjusted by the hydraulic cylinder 202 to align the bottom of the grouting pipe 5 with the grouting hole, and the sealing ring 6 seals the grouting hole. Under normal conditions, the grouting machine body adopts its own normal grouting pressure for the water-rich sand and gravel stratum. When the slurry has a poor penetration effect or even no penetration in the water-rich sand and gravel stratum due to insufficient penetration pressure, the grouting pressure is adjusted and switched, and the grouting machine body no longer grouts into the slurry discharge chamber 302. The grouting pressure is adjusted and switched by the impact drive mechanism and the propulsion mechanism. The output end of the electric push rod 8 is extended, and when the electric hammer is moved downward, the piston is driven downward at the same time, and the piston is moved between the punching chamber 303 and the slurry discharge chamber 302. Figure 4 As shown, at this time, the piston 12 blocks the slurry inlet chamber 301, and part of the slurry in the cross-shaped four-way pipe will be squeezed into the buffer chamber 304, and the sealing slide 902 squeezes the pressure spring 901 to make way for the slurry. When the piston 12 is located between the punching chamber 303 and the slurry outlet chamber 302, the piston 12 also blocks the slurry outlet chamber 302, and the electric hammer 7 is started. The electric hammer 7 controls the piston 12 to achieve high-frequency vibration impact, thereby increasing the grouting pressure in the grouting pipe 5. The high-frequency vibration impact force is used to directly increase the penetration pressure of the slurry in the formation, so that the slurry can fully penetrate the water-rich sand and gravel formation, and the foundation pit of the water-rich sand and gravel formation is consolidated and grouting is performed.

[0033] At the same time, a foundation pit sealing and water-stopping method based on a grouting machine is proposed, comprising the following steps:

[0034] S1: The foundation pit is surrounded by large slopes and mesh spraying. According to the construction drawings, the positions of the grouting holes are determined and marked on the unexcavated foundation pit. The spacing between adjacent grouting holes can be set to 2.5m or 3m, and the grouting holes are sequenced.

[0035] S2: Use a hydraulic rotary drill and follow-through drilling to drill grouting holes according to the designed final hole depth. The deviation of the grouting hole azimuth angle should not exceed 5 degrees, and the deviation of the top angle should not exceed 2 degrees. After the drilling is completed, the hole is flushed to openly flush the residual rock powder in the hole.

[0036] S3: Water pressure test: a water pressure test is conducted on the grouting holes using the single-point method. Under stable pressure, the pressure flow rate is measured every 5 minutes. The water pressure test is terminated if the difference between the maximum and minimum values ​​of four consecutive readings is less than 10% of the final value or the difference between the maximum and minimum values ​​of four consecutive readings is less than 1L / min.

[0037] S4: Align the grouting pipe of the grouting machine with the grouting hole and block the grouting hole. The grouting machine performs controlled grouting within the designed stratum thickness range. The grouting adopts the full-hole section pure pressure method with a water-cement ratio of 1:1. The water-rich sand and gravel strata on the slopes and bottom of the foundation pit are consolidated by grouting. The consolidation grouting depth is based on the pressure principle. The consolidation thickness of the pressure cap is greater than the external water seepage pressure. For example, the water head difference between the inner and outer sides of the foundation pit is about 10m. The consolidated bulk density of the sand and gravel material is 20KN / m 3 For calculation, the surface of the sand and gravel foundation can be considered to have a consolidation depth of 5.0m;

[0038] S5: After the consolidation grouting is completed, the grouting hole is sealed by mechanical grouting with slurry of a water-cement ratio of 0.5:1. The mechanical grouting sealing method is as follows: the pipeline is lowered to the bottom of the grouting hole, and the grouting machine body first presses slurry of a water-cement ratio of 0.5:1 into the grouting hole, and then rises from the grouting hole to push out the accumulated water in the grouting hole until slurry appears in the grouting hole, and the pipeline is pulled out;

[0039] S6: After the consolidation grouting of the foundation pit is completed, the foundation pit is excavated using an excavator and a soil transport vehicle.

[0040] Example 2, a water-rich sand and gravel stratum foundation pit grouting machine with controllable slurry penetration pressure and a sealing and water-stopping method in this embodiment are described centering on the differences from Example 1.

[0041] During the implementation of Example 1, the grouting pipe uses a sealing ring to block the grouting hole. The sealing ring cannot adapt to grouting holes of different apertures. At the same time, considering that there is high-frequency vibration impact in the grouting pipe, it is also impossible to simply use a sealing airbag for sealing. The sealing airbag will be damaged by friction. Therefore, an auxiliary sealing component is set on the grouting pipe, such as Figure 5-6As shown, the sealing sleeve roller 15 can be fixed on the grouting pipe 5, one end of the sealing sleeve roller 15 is a sleeve structure, and a plurality of oblique locking pieces 16 are connected radially and tilted inwardly in the sleeve, and a matching snap ring 17 corresponding to the oblique locking piece is fixed in the docking spool 14. The docking spool 14 can be fitted in the sleeve, and the other end of the sealing sleeve roller 15 is an I-shaped structure. An annular airbag 13 is fixed on the docking spool and the outer end of the sealing sleeve roller, and the adjacent annular airbags are connected, and the input end thereof is connected to the external air pump. When in use, the docking spool 14 It is sleeved in the sleeve of the sealing sleeve roller 15, and the matching clamping ring 17 can squeeze the oblique locking piece 16 to increase the stability of the docking I-wheel. When the sealing sleeve roller is sealed at the grouting hole, the air pump starts to inflate the annular airbag 13, and the grouting hole is sealed by the expanded annular airbag 13 on the sealing sleeve roller 15. After the annular airbag on the docking I-wheel 14 is expanded, it seals the inside of the sleeve of the sealing sleeve roller. At the same time, when the docking I-wheel is subjected to high-frequency vibration impact, the matching clamping ring will apply extrusion force to the oblique locking piece to firmly seal the grouting pipe and achieve double sealing.

[0042] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A grouting machine for foundation pit in water-rich sand and gravel formation with controllable slurry penetration pressure, characterized in that: The grouting machine comprises a main body, an auxiliary frame is installed on the main body of the grouting machine, a guide tube is matched at the free end of the auxiliary frame, and a telescopic part for controlling the retraction and extension of the guide tube is provided on the auxiliary frame, and a grouting pipe is provided in the guide tube, and a sealing assembly is provided at the bottom of the grouting pipe, a cross-shaped four-way pipe is provided above the guide tube, a control cylinder is connected above the cross-shaped four-way pipe, and the interior of the cross-shaped four-way pipe is divided into a slurry inlet chamber, a slurry outlet chamber, a punching chamber and a buffer chamber, the interior right side of the cross-shaped four-way pipe is a slurry inlet chamber, the interior left side is a buffer chamber, the interior upper side is a punching chamber, the interior lower side is a slurry outlet chamber, and the piston matches It is equipped in the stamping chamber, and an electric hammer is provided in the control cylinder to control the high-frequency vibration impact of the piston, and the output end of the electric hammer is fixedly connected to the piston; a propulsion mechanism for moving the electric hammer is also provided inside the control cylinder, and a cache clearance component is also provided in the cache chamber, and the cache clearance component includes a pressure spring provided in the cache chamber, and the front end of the pressure spring is connected to a sealing slide; the propulsion mechanism can drive the piston when controlling the movement of the electric hammer, and when the piston moves between the stamping chamber and the slurry discharge chamber, the electric hammer can control the piston to achieve high-frequency vibration impact, increase the grouting pressure, and improve the penetration pressure of the slurry.

2. A grouting machine for foundation pit in water-rich sand and gravel strata with controllable slurry penetration pressure according to claim 1, characterized in that: The auxiliary frame includes an articulated rod arranged in parallel up and down, one end of the articulated rod is hinged on the column of the grouting machine body, and the other end is hinged on the guide tube. The telescopic member is a hydraulic cylinder, and the two ends of the hydraulic cylinder are respectively hinged on the column and the guide tube.

3. The grouting machine for foundation pit in water-rich sand and gravel strata with controllable slurry penetration pressure according to claim 1, characterized in that: The propulsion mechanism is an electric push rod, which is fixed in the control cylinder, and the output end of the electric push rod is fixedly connected to the tail of the electric hammer. The electric push rod controls the movement of the electric hammer to vertically adjust the position of the piston, move the piston between the punching chamber and the pulp discharge chamber, and seal the pulp inlet chamber.

4. The grouting machine for foundation pit in water-rich sand and gravel strata with controllable slurry penetration pressure according to claim 1, characterized in that: It also includes an auxiliary sealing component for auxiliary sealing of the grouting hole.

5. A sealing and water-stopping method using any one of the grouting machines of claims 1-4, characterized in that: The following steps are involved: S1: Large slope and mesh spraying are used around the foundation pit. The grouting holes are located on the unexcavated foundation pit according to the construction drawings and marked. The spacing between adjacent grouting holes is set at 2.5m or 3m, and the grouting holes are sequenced. S2: Use a hydraulic rotary drill and follow-through drilling to drill grouting holes according to the designed final hole depth. The deviation of the grouting hole azimuth angle should not exceed 5 degrees, and the deviation of the top angle should not exceed 2 degrees. After the drilling is completed, the hole is flushed to openly flush the residual rock powder in the hole. S3: Water pressure test: a water pressure test is conducted on the grouting holes using the single-point method. Under stable pressure, the pressure flow rate is measured every 5 minutes. The water pressure test is terminated if the difference between the maximum and minimum values ​​of four consecutive readings is less than 10% of the final value or the difference between the maximum and minimum values ​​of four consecutive readings is less than 1L / min. S4: Align the grouting pipe of the grouting machine with the grouting hole and block the grouting hole. The grouting machine performs controlled grouting within the designed stratum thickness range. The grouting adopts the full-hole section one-time pure pressure method to consolidate the water-rich sand and gravel strata on the surrounding foundation pit slopes and the bottom of the foundation pit. The consolidation grouting depth is based on the pressure weight principle. The consolidation thickness of the gland is greater than the external water seepage pressure. S5: After the consolidation grouting is completed, the grouting holes are sealed by mechanical grouting with a slurry with a water-cement ratio of 0.5:1; S6: After the consolidation grouting of the foundation pit is completed, the foundation pit is excavated using an excavator and a soil transport vehicle.

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