Leaking stoppage method for wall seam leakage point

Abstract

The invention relates to the technical field of underground diaphragm wall construction, in particular to a leaking stoppage method for wall seam leakage of an ultra-deep underground diaphragm wall. According to the method, whether the leakage point appears or not is judged through the observation hole, grouting is conducted on the upper portion and the lower portion of the leakage point by a certain distance, and leaking stoppage in a large area of the leakage point is achieved. The method has the advantages that the construction process is simple, and the cost can be greatly saved.

Description

Technical Field

[0001] The invention relates to the technical field of underground continuous wall construction, in particular to a method for plugging leakage in wall seams of underground continuous walls. Background Art

[0002] Ground-connected walls play a vital role in the development of urban underground space. However, due to factors such as construction technology and geological conditions, leakage may occur at the joints of ground-connected walls, affecting the safety of the foundation pit and the surrounding environment. Traditional plugging methods are often ineffective, especially when the leakage point is located at a deeper depth.

[0003] The Chinese invention patent "A steel cage structure and construction method for dealing with joint or wall leakage" (application number 202210875686.3) includes the following steps: Step 1: Ground-connected wall leakage detection; Step 2: Geological radar scanning to prevent the existence of voids at the bottom; Step 3: Block the steel plate at the weak ground-connected wall joints to prevent gushing at the weak wall joints; Step 4: Use high-pressure rotary jet piles to stop the wall joints at the ground-connected wall joints; Step 5: WSS grouting reinforcement at the risky ground-connected wall joints during excavation; Step 6: Add drainage and pressure reduction wells outside the pit; Step 7: Set up supports in time, carry out slope excavation, and strictly implement the slotting and seam inspection system; Step 8: Strengthen on-site construction monitoring and guide foundation pit excavation through monitoring data. The radar equipment used in this patent is relatively expensive, and it cannot detect deeper places. Generally, the detection effect is poor when it is greater than 15 meters. Secondly, the excavation process is large in engineering volume and relatively expensive. Summary of the invention

[0004] The present invention aims at the deficiencies of the prior art and proposes an effective method for plugging leakage points of wall joints to solve the leakage problem of the ground-connected wall joints, thereby ensuring the safety of the foundation pit and the smooth progress of the construction. The present invention has the characteristics of small engineering volume and relatively economical and applicable.

[0005] The technical solution of the present invention is: a method for plugging leakage at wall joints, characterized in that it comprises the following steps: Step 1, starting from the intersection of the wall widths, drilling observation holes within a distance of 1m, and drilling multiple observation holes on each side as required, such as Figure 1 Drill two observation holes for each side, and the observation holes are deep to the bottom of the wall;

[0006] Step 2: Lower the camera into the observation hole, and observe the tightness of the wall joints of the ground-connected wall by shooting data with the camera to find out whether there are any leakage points. If there is no leakage point at the height h, no treatment is required. If there is a leakage point at the depth h, the subsequent steps are performed;

[0007] Step 3: If leakage is found at position h, the observation hole is enlarged;

[0008] Step 4: Place the first grouting pipe and the second grouting pipe in the observation hole after expansion. The first grouting pipe is placed 5m below the leakage point. The bottom 5m of the first grouting pipe is a flower pipe, and the flower pipe mouth is wrapped with tape in front of the pipe; the second grouting pipe is placed 1m above the leakage point;

[0009] Step 5: During grouting, grouting is first performed through the second grouting pipe, and the grouting pressure is stopped after reaching the grouting pressure, and the grouting pressure is determined according to the construction requirements;

[0010] Step 6: After the external grouting is completed, wait for a period of time and then grout the first grouting pipe. When the grouting pressure is reached, stop. The grouting pressure is determined according to the construction requirements.

[0011] Generally, the grouting pressure is not more than 1MPa, and the grouting water-cement ratio is 1:1; the external grouting is completed.

[0012] Step 7: After the grouting is completed, the detection equipment is lowered to the leakage point to observe the leakage situation. If there is no leakage, deep observation can be carried out. If leakage exists, repeat the above operation.

[0013] According to the method for plugging a wall leakage point as described above, the feature is that the wall bottom depth is 30m, and the observation hole depth is greater than or equal to 30m.

[0014] According to the method for plugging a wall leakage point as described above, it is characterized in that: in step 3, the diameter of the observation hole after hole expansion is 100 mm to 150 mm.

[0015] According to the method for plugging a wall leak, the feature of the method is that in step 3, the verticality of the observation hole after hole expansion is less than 0.5%.

[0016] According to the method for plugging a wall leakage point as described above, it is characterized in that: in step 5, the grouting pressure is not greater than 1MPa, and the ratio of cement slurry: water glass in the grouting is 1:1; and the external grouting is completed.

[0017] According to the method for plugging a wall leakage point as described above, it is characterized in that: in step 6, the grouting pressure is not greater than 1MPa, and the grouting water-cement ratio is 1:1.

[0018] The beneficial effects of the present invention are as follows: more than 98% of wall seam leakage points occur at the intersection of wall widths. The present invention determines whether a leakage point occurs through an observation hole, and performs grouting at a distance above and below the leakage point to achieve leakage plugging in a larger area of ​​the leakage point. The method of the present invention has the advantages of simple construction process and can greatly save costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the inner structure of the foundation pit.

[0020] Figure 2 Schematic diagram of the leakage point.

[0021] Explanation of the accompanying drawings: observation hole 1, first grouting pipe 2, second grouting pipe 3. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below in conjunction with the accompanying drawings.

[0023] like Figure 1 and Figure 2 As shown, a method for plugging a wall leakage point of the present invention comprises the following steps:

[0024] Step 1: Starting from the intersection of the wall, drill an observation hole 1 within a horizontal distance of 1m. Multiple observation holes 1 can be drilled on each side as required, such as Figure 1 Two observation holes 1 are drilled for each side, and the depth of the observation hole 1 is to the bottom of the wall; if the depth of the bottom of the wall is 30m, the depth of the observation hole 1 is greater than or equal to 30m. The hole spacing of the observation holes 1 of the present invention is generally small, such as a diameter between 10mm and 30mm, and after the observation hole 1 is drilled, observation is carried out as soon as possible, so as to effectively avoid the collapse of the observation hole 1.

[0025] Step 2: lower a tiny high-definition camera into the observation hole 1, and use the camera to take pictures to observe the tightness of the wall joints of the ground-connected wall to find out whether there are any leakage points. For the height h where there is no leakage point, no treatment is required, and for the depth h where there is a leakage point, the subsequent steps are performed;

[0026] Step 3, when leakage is found at h, the observation hole 1 is expanded, and the diameter of the observation hole 1 after expansion is 100 mm to 150 mm, such as 110 mm; the verticality of the observation hole 1 after expansion is less than 0.5%;

[0027] Step 4: Place the first grouting pipe 2 and the second grouting pipe 3 in the observation hole 1 after expansion. The first grouting pipe 2 is placed 5m below the leakage point. The bottom 5m of the first grouting pipe 2 is a flower pipe, and the flower pipe mouth is wrapped with tape in front of the pipe; the second grouting pipe 3 is placed 1m above the leakage point. The purpose of laying two grouting pipes is: the grouting of the second grouting pipe 3 plays the role of sealing the aquifer in the formation, the grouting of the first grouting pipe 2 plays the role of precise plugging, and the flower pipe can ensure the uniform diffusion of the double liquid slurry.

[0028] Step 5, during grouting, grouting is first performed through the second grouting pipe 3, and the grouting pressure is stopped after reaching the grouting pressure. The grouting pressure is determined according to the construction requirements. Generally, the grouting pressure is not greater than 1MPa, and the ratio of cement slurry to water glass in the grouting is 1:1; the external grouting is completed.

[0029] Step 6: After the external grouting is completed, wait for a period of time, generally after an interval of 2 days, and then carry out grouting in the first grouting pipe 2. Stop when the grouting pressure is reached. The grouting pressure is determined according to the construction requirements. Generally, the grouting pressure is not more than 1MPa, and the grouting water-cement ratio is 1:1; the external grouting is completed.

[0030] Step 7: After the grouting is completed, the detection equipment is lowered to the leakage point to observe the leakage situation. If there is no leakage, deep observation can be carried out. If leakage exists, repeat the above operation.

[0031] Methods for judging mud leakage: First, check the mud level regularly. For example, use sonic logging tools to detect downhole conditions, which can reveal abnormalities in the well wall. If the mud rises, it means there is still leakage. Second, use a mud densitometer to measure the density of the mud regularly. If the density changes suddenly, it may be caused by the mixing of mud with groundwater or leakage.

[0032] The entire plugging method of the present invention takes into account the entire process from detection to repair, and effectively solves the problem of leakage in the ground-connected wall by accurately locating the leakage point and using double-tube grouting technology. At the same time, strict process control and safety measures ensure the smooth progress of the plugging project.

Claims

1. A method for plugging leakage at a wall joint, characterized in that: The method comprises the following steps: Step 1, starting from the intersection of the wall width, within a distance of 1m, to prevent vertical deviation during drilling from causing damage to the ground-connected wall, drilling an observation hole (1), drilling multiple observation holes (1) on each side as required, drilling two observation holes (1) on each side, and the depth of the observation hole (1) is to the bottom of the wall; Step 2, lower the camera into the observation hole (1), and observe the tightness of the wall joints of the ground-connected wall by shooting data with the camera to find out whether there are any leakage points. If there is no leakage point at the height h, no treatment is required. If there is a leakage point at the depth h, the subsequent steps are performed; Step 3: If leakage is found at position h, the observation hole (1) is enlarged; Step 4, placing the first grouting pipe (2) and the second grouting pipe (3) in the expanded observation hole (1), the first grouting pipe (2) being placed 5 m below the leakage point, the bottom 5 m of the first grouting pipe (2) being a flower pipe, the flower pipe opening being wrapped with tape in front of the pipe; the second grouting pipe (3) being placed 1 m above the leakage point; Step 5: During grouting, grouting is first performed through the second grouting pipe (3), and the grouting pressure is stopped after reaching the grouting pressure, and the grouting pressure is determined according to the construction requirements; Step 6: After the external grouting is completed, wait for a period of time and then perform grouting in the first grouting pipe (2). The grouting pressure is stopped when it reaches the grouting pressure. The grouting pressure is determined according to the construction requirements. Grouting pressure is not more than 1MPa, grouting water-cement ratio: 1:1; complete external grouting; Step 7: After the grouting is completed, the detection equipment is lowered to the leakage point to observe the leakage situation. If there is no leakage, deep observation can be carried out. If leakage exists, repeat the above operation.

2. A method for plugging a wall leak according to claim 1, characterized in that: The depth of the wall bottom is 30m, and the depth of the observation hole (1) is greater than or equal to 30m.

3. A method for plugging a wall leak according to claim 1, characterized in that: In step 3, the diameter of the observation hole (1) after expansion is 100 mm to 150 mm.

4. A method for plugging a wall leak according to claim 1, characterized in that: In step 3, the verticality of the observation hole (1) after expansion is less than 0.5%.

5. A method for plugging a wall leakage point according to claim 1, characterized in that: In step 5, the grouting pressure is no more than 1 MPa, and the ratio of cement slurry to water glass in the grouting is 1:1; the external grouting is completed.

6. A method for plugging a wall leak according to claim 1, characterized in that: In step 7, the method for determining mud leakage is to regularly check the mud level.

7. A method for plugging a wall leak according to claim 1, characterized in that: In step 7, the method for determining mud leakage is to use a mud densitometer to regularly measure the density of the mud.

Images