CN115821997A - Construction method for actively controlling deformation of building through multi-row grouting - Google Patents

Abstract

The invention discloses a construction method for actively controlling deformation of a building by multi-row grouting, which comprises the following steps: obtaining the number and the positions of a plurality of rows of grouting holes between the building structure to be rectified and the foundation pit and the range of grouting expansion areas in the grouting holes through theoretical calculation or numerical simulation calculation; preparing grouting pipes, wherein each grouting pipe consists of a pipe A and a pipe B which are bound together, the axes of the pipe A and the pipe B are parallel, the top surfaces of the pipe A and the pipe B are flush, the length of the pipe B is greater than that of the pipe A, and the area between the bottom wall of the pipe B and the bottom wall of the pipe A is a grouting expansion area; drilling a grouting hole by using a drilling machine according to a preset position; digging a foundation pit on the inner side of the underground diaphragm wall, measuring the horizontal deformation of the building structure to be rectified by using an instrument in a segmented mode, and inserting a grouting pipe into a grouting hole in the position corresponding to the horizontal deformation for grouting according to the horizontal deformation measuring result of the building structure when the horizontal deformation exceeds the alarm value set before engineering construction. The method can effectively increase the effect of deformation regulation and control.

Description

A Construction Method for Actively Controlling the Deformation of Building Structures by Multiple Rows of Grouting

technical field

The invention relates to an underground engineering construction method, in particular to an implementation method for controlling the horizontal deformation of structures such as tunnels and subway stations during the construction process.

Background technique

The foundation pit construction for the development of underground space will inevitably cause deformation of the surrounding soil, which will lead to deformation of buildings such as tunnels and subway stations in the soil. This poses a threat to the structural safety and operational safety of subway lines, and also brings new challenges to the design level and construction technology of foundation pits. In order to reduce the impact of foundation pit construction on adjacent existing tunnels and other structures, it is necessary to take necessary control measures. Existing protection measures can be divided into active protection measures and passive protection measures.

Active control measures mainly include grouting and horizontal support axial force servo control technology. At present, there are many studies on grouting uplifting existing buildings or tunnels, but less research on grouting to control the horizontal deformation of tunnels and other structures, and there is still a lack of systematic grouting theory and strategies to control their horizontal deformation. The control ability of the traditional grouting compensation technology has certain limitations. The extensive grouting method ignores the research on the grouting sequence, and it is difficult to effectively improve the deformation effect of the object to be corrected. It also has an impact on the construction of surrounding projects and cannot be maximized. The effect of the deformation control.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the prior art and provide a construction method for actively controlling the deformation of structures such as tunnels with multiple rows of grouting that can efficiently restore the deformation of structures such as tunnels without affecting other surrounding structures.

In order to solve the above-mentioned technical problems, it is realized through the following technical solutions.

The invention proposes a construction method for actively controlling the deformation of buildings and structures by multi-row grouting, which includes the following steps:

Step 1. Obtain the number and position of the multiple rows of grouting holes located between the structure to be corrected and the foundation pit and the range of the grouting expansion area in the grouting holes through theoretical calculation or numerical simulation calculation. The multiple rows of grouting holes are based on theoretical Calculation or numerical simulation results are arranged in two, three or more rows;

Step 2. Prepare the grouting pipes. Each grouting pipe is composed of A pipe and B pipe bound together. The axes of A pipe and B pipe are parallel and the top surfaces are flush. The length of the B pipe is greater than the length of the A pipe. , the area between the bottom wall of the B pipe and the bottom wall of the A pipe is the grouting expansion area;

Step 3. Use a drilling machine to drill the grouting hole according to the position set in step 1, and use mud to protect the wall during the drilling of the grouting hole;

Step 4: Excavate the foundation pit on the inner side of the ground connection wall, and use the instrument to measure the horizontal deformation of the structure to be corrected in sections. When the horizontal deformation exceeds the alarm value set before the construction, according to the measurement results of the horizontal deformation of the building Insert the grouting pipe into the grouting hole at the position corresponding to the horizontal deformation, and then perform the following grouting process:

The first step is to start grouting from a row of grouting holes that are far away from the structure to be corrected. When grouting into the grouting pipe in the grouting hole, the grout is first injected through the B pipe of the grouting pipe until The entire grouting hole is filled with cement slurry;

In the second step, the water glass is injected through the A pipe of the grouting pipe, so that the cement slurry is mixed with the water glass within the length of the A pipe below the ground surface in the grouting hole, and the hole is sealed;

In the third step, the double liquid slurry is injected through the B pipe of the grouting pipe; the double liquid slurry is made by mixing cement slurry and water glass;

In the fourth step, during the grouting process, continue to measure the horizontal deformation recovery of the structure to be corrected, repeat the first step to the third step repeatedly, and grout to each row according to the grouting sequence from far to near to the area to be controlled The grouting pipe in the hole is grouted until the horizontal deformation of the structure to be corrected decreases below the alarm value.

The beneficial results of the present invention are:

1. Through the sequence of grouting from far to near, the soil in the area of grouting in advance has a counter force effect on the deformation of the soil on the side of the subsequent grouting, so that the effect of subsequent grouting on the horizontal displacement of the soil on the same side as the grouting direction Larger, effectively increasing the effect of deformation control.

2. The soil in the first grouting area has a blocking effect on the deformation of the soil on the other side of the subsequent grouting, and the horizontal displacement of the soil on the side opposite to the grouting direction is reduced, which can reduce the impact on the structures on the other side of the grouting sequence .

3. Efficient and economical, with a wide range of applications, the correction object can be various buildings such as tunnels, subway stations or foundation pit enclosure structures.

Description of drawings

Figure 1 is a sectional view of the grouting expansion area;

Figure 2 is a schematic diagram of a single hole grouting process;

Fig. 3 is a schematic diagram of the grouting sequence of each row of grouting holes;

Figure 4 is a schematic diagram of the horizontal displacement effect of the soil after the grouting is completed.

Detailed ways

In order to make the purpose, solution and advantages of the present invention clearer, the present invention will be further described below in conjunction with the accompanying drawings and a specific implementation case.

The principle of the method of the present invention is to use the shielding effect of the soil mass in the preceding grouting area on the deformation of the soil mass on the other side of the subsequent grouting, and combine theoretical calculation and As a result of numerical simulation, the location and number of grouting holes are determined to increase the control effect on the object to be corrected and reduce the negative impact on other nearby structures.

As shown in Figures 1-3, a method for implementing multi-row grouting to actively control the deformation of buildings and structures of the present invention includes the following steps:

Step 1. When horizontal deformation of structures such as tunnels or subway stations occurs due to excavation of foundation pits, etc., through theoretical calculation or numerical simulation (for example, software such as PLAXIS or FLAC), it is calculated that the structure 2 and the foundation pit located in the proposed deviation correction The number and position of the multiple rows of grouting holes between 3 and the scope of the grouting expansion area 1 in the grouting holes, preferably, the line of the center of each row of grouting holes is parallel to the axial direction of the structure 2 to be corrected; Multiple rows of grouting holes are arranged in two, three or more rows according to theoretical calculation or numerical simulation results. The diameter of the grouting hole may be 50-60 mm.

Step 2. Prepare the grouting pipes. Each grouting pipe is composed of A pipe and B pipe bound together. The axes of A pipe and B pipe are parallel and the top surfaces are flush. The length of the B pipe is greater than the length of the A pipe. , the area between the bottom wall of the B pipe and the bottom wall of the A pipe is the grouting expansion area 1 . The bottom of the grouting pipe is perforated to facilitate the flow of grout. The size of the grouting expansion area can be controlled by adjusting the length of pipe A and pipe B.

Step 3. Use a drilling machine to drill the grouting hole according to the position set in step 1. During the drilling of the grouting hole, use mud to protect the wall to prevent the hole from collapsing. The bottom elevation of the grouting hole is consistent with the theoretical calculation or numerical simulation results.

Step 4: Excavate the foundation pit 3 on the inner side of the ground connection wall, and use multiple levels or total stations to measure the horizontal deformation of the structure 2 to be corrected in sections. The measuring points of the structure to be corrected are along its length according to the measurement specifications Layout, when the horizontal deformation exceeds the alarm value established according to the relevant building deformation specifications before construction, according to the horizontal deformation measurement results of the building, insert the grouting pipe into the grouting hole at the position corresponding to the horizontal deformation, and then execute The following grouting process:

The first step is to start grouting from a row of grouting holes that are far away from the structure 2 to be corrected. As shown in Figure 3, when grouting into the grouting pipe in the grouting hole, first pass through the grouting pipe. Pipe B injects cement slurry until the entire grouting hole is filled with cement slurry;

In the second step, the water glass is injected through the A pipe of the grouting pipe, so that the cement slurry is mixed with the water glass within the length of the A pipe below the ground surface in the grouting hole, and the hole is sealed; the water-cement ratio of the cement slurry is preferably 0.6-0.7.

The third step is to inject double liquid grout through the B pipe of the grouting pipe to control the soil deformation. The double liquid slurry is formed by mixing cement slurry and water glass. The volume ratio of cement slurry to water glass in double liquid slurry is 3:1. The mixture of cement slurry and water glass can quickly solidify in a short time to form strength.

In the fourth step, during the grouting process, continue to measure the horizontal deformation recovery of the structure to be corrected, repeat the first step to the third step repeatedly, and grout to each row according to the grouting sequence from far to near to the area to be controlled The grouting pipe in the hole is grouted until the horizontal deformation of the structure to be corrected decreases below the alarm value.

The deviation correction object of the implementation method is applicable to various structures such as tunnels, subway stations, foundation pit enclosure structures, etc., and has a wide application range, good deformation control effect, and small reaction force to the foundation pit.

The completion of grouting and the final horizontal displacement effect are shown in Figure 4. After the grouting is completed according to the above grouting sequence, the impact on the structural displacement on the side of the foundation pit is small (as shown by the curve on the left side of the grouting hole). The regional influence effect is significant (as shown by the curve on the right side of the grouting hole), that is, because the front row of grouting has been performed, the rear row of grouting makes the horizontal displacement of the soil body larger on the same side as the grouting direction, while the side opposite to the grouting direction The horizontal displacement of the soil is smaller, and the grouted soil will have a reaction force effect and a shielding effect on the subsequent grouting effect.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, people can also make many forms without departing from the purpose of the present invention and the scope of protection of the claims, and these all belong to the protection scope of the present invention.

Claims (4)

1. An implementation method for actively controlling the deformation of a multi-row grouting structure, characterized in that it comprises the following steps: Step 1. Obtain the number and position of the multiple rows of grouting holes located between the structure to be corrected and the foundation pit and the range of the grouting expansion area in the grouting holes through theoretical calculation or numerical simulation calculation. The multiple rows of grouting holes are based on theoretical Calculation or numerical simulation results are arranged in two, three or more rows; Step 2. Prepare the grouting pipes. Each grouting pipe is composed of A pipe and B pipe bound together. The axes of A pipe and B pipe are parallel and the top surfaces are flush. The length of the B pipe is greater than the length of the A pipe. , the area between the bottom wall of the B pipe and the bottom wall of the A pipe is the grouting expansion area; Step 3. Use a drilling machine to drill the grouting hole according to the position set in step 1, and use mud to protect the wall during the drilling of the grouting hole; Step 4: Excavate the foundation pit on the inner side of the ground connection wall, and use the instrument to measure the horizontal deformation of the structure to be corrected in sections. When the horizontal deformation exceeds the alarm value set before the construction, according to the measurement results of the horizontal deformation of the building Insert the grouting pipe into the grouting hole at the position corresponding to the horizontal deformation, and then perform the following grouting process: The first step is to start grouting from a row of grouting holes that are far away from the structure to be corrected. When grouting into the grouting pipe in the grouting hole, the grout is first injected through the B pipe of the grouting pipe until The entire grouting hole is filled with cement slurry; In the second step, the water glass is injected through the A pipe of the grouting pipe, so that the cement slurry is mixed with the water glass within the length of the A pipe below the ground surface in the grouting hole, and the hole is sealed; In the third step, the double liquid slurry is injected through the B pipe of the grouting pipe; the double liquid slurry is made by mixing cement slurry and water glass; In the fourth step, during the grouting process, continue to measure the horizontal deformation recovery of the structure to be corrected, repeat the first step to the third step repeatedly, and grout to each row according to the grouting sequence from far to near to the area to be controlled The grouting pipe in the hole is grouted until the horizontal deformation of the structure to be corrected decreases below the alarm value. 2. The implementation method of multi-row grouting for actively controlling deformation of buildings and structures according to claim 1, characterized in that: the water-cement ratio in the grout is 0.6-0.7. 3. The implementation method for multi-row grouting to actively control the deformation of buildings and structures according to claim 1 or 2, characterized in that: the volume ratio of cement slurry to water glass in the double liquid slurry is 3:1. 4. The method for actively controlling the deformation of a building with multiple rows of grouting according to claim 3, wherein the line connecting the centers of each row of grouting holes is parallel to the axial direction of the structure to be corrected.

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