An adaptive directional grouting system

Abstract

The utility model discloses an adaptive directional grouting system, including a plurality of grouting holes formed in a grouting area, a grouting pipe arranged in the grouting hole, a plurality of pipe wall channels arranged on the pipe wall of the grouting pipe, and the types of pipe wall channels on the pipe wall of the grouting pipe include: (1) channels evenly distributed on all sides, (2) channels with a 90 degree shape in three directions, (3) channels with a 180 degree shape in two directions, and (4) channels with a 90 degree shape in two directions. The side holes adopt grouting pipes with channels with a 90 degree shape in three directions and / or channels with a 180 degree shape in two directions, the corner holes adopt grouting pipes with channels with a 90 degree shape in two directions; the internal holes adopt grouting pipes with channels evenly distributed on all sides. By adopting the system described in the utility model, the grouting area can be controlled more accurately, especially in terms of height and direction control, which has unique advantages, can prevent slurry cross-flow, improve grouting efficiency and reduce grouting costs.

Description

Technical Field

[0001] The utility model relates to a grouting technology for a foundation or underground structure in the field of geotechnical engineering, in particular to an adaptive directional grouting system. Background Art

[0002] Grouting is a technique commonly used in underground engineering for ground reinforcement or water blocking. It is to prepare materials with filling and cementing properties into slurry, and inject them into the pores, cracks or voids of the ground through grouting pipes with grouting equipment. After diffusion, solidification and hardening, the slurry reduces the permeability of rock and soil, increases its strength and stability, and thus achieves the purpose of water blocking or ground reinforcement. The main advantages of grouting are: less equipment required, simple process, reliable method, low cost and good effect. Therefore, it has been widely used in various fields of civil engineering such as water conservancy and hydropower, mining, transportation tunnels, building foundations, slopes, etc. There are many classifications of grouting, among which static pressure grouting can be divided into filling or crack grouting, penetration grouting, compaction grouting and splitting grouting, all of which can be used to fill cracks and reinforce foundations.

[0003] Although the development of grouting has achieved good technical and economic results, there are still many uncertainties in the controllability of slurry due to the characteristics of the distribution of pores and fissures in the formation. In terms of grouting height, the grout stopper is currently used to separate the borehole to be grouted up and down according to the design requirements, so as to divide the grouting section height and control the slurry to be injected into the rock fissures in this section. The position of the stopper in the borehole should be where the surrounding rock is stable, there are no longitudinal cracks and the hole shape is regular. Its setting has great limitations. In terms of the control of the slurry diffusion direction, it basically depends on the random distribution characteristics of the pores and fissures. In many cases, the slurry does not follow the predetermined direction and diffusion radius at all, and the expected grouting effect is far from being achieved, resulting in serious waste.

[0004] In recent years, the concept of precision grouting has been continuously proposed. However, the current precision grouting is limited to horizontal directional drilling grouting technology. For example, Wu Shanyuan et al. proposed a feasible and effective precision grouting technology for plugging aquifer fissures and controlling the expansion range of slurry through the optimized layout of directional drilling and real-time monitoring of hydrological observation holes above and below the well, achieving high-quality and comprehensive plugging of aquifer fissures (Wu Shanyuan, Liu Lei, Chen Juntao, et al. Research on precision grouting technology for water prevention and control in directional drilling in Huanghe North Coalfield [J]. Coal Science and Technology, 2019, 47 (5): 34-40). At the drilling scale, it is not possible to achieve effective control of the formation height and the slurry diffusion direction. Utility Model Content

[0005] The utility model aims to provide an adaptive directional grouting system, which can realize accurate control of grouting at set formation height and direction, avoid disorderly diffusion of slurry in non-designed areas, and improve grouting quality and efficiency.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0007] An adaptive directional grouting system comprises a plurality of grouting holes formed in a grouting area, wherein a grouting pipe is arranged in the grouting hole, and a plurality of pipe wall channels are arranged on the pipe wall of the grouting pipe. The types of pipe wall channels on the pipe wall of the grouting pipe include: (1) uniformly distributed channels, wherein at least four channels are evenly arranged on the same cross section of the pipe wall; (2) three-direction 90-degree channels, wherein three channels are arranged on one side of the same cross section of the pipe wall, and the channels are spaced 90 degrees apart; (3) two-direction 180-degree channels, wherein two channels are symmetrically arranged on the same cross section of the pipe wall; and (4) two-direction 90-degree channels, wherein two channels are arranged on the same cross section of the pipe wall, and the two channels are spaced 90 degrees apart.

[0008] Furthermore, the grouting holes include curtain holes and internal holes, and the curtain holes are composed of side holes and corner holes; wherein the side holes adopt grouting pipes with 90-degree type channels in three directions and / or grouting pipes with 180-degree type channels in two directions, and the corner holes adopt grouting pipes with 90-degree type channels in two directions; the internal holes adopt grouting pipes with channels evenly distributed all around.

[0009] Furthermore, the adaptive directional grouting pipe adopts a polypropylene pipe with an elastic modulus E=1.32-1.42GPa. When the grouting pressure is 2.5MPa, the wall thickness is 2.0mm, and the diameter of the grouting pipe is 10-15mm smaller than the grouting hole.

[0010] Furthermore, the adaptive directional grouting pipe adopts a polytetrafluoroethylene pipe with an elastic modulus E=1.14-1.42GPa. When the grouting pressure is 2.5MPa, the wall thickness is 2.0mm, and the diameter of the grouting pipe is 10-15mm smaller than the grouting hole.

[0011] Furthermore, the adaptive directional grouting pipe adopts a polyvinyl chloride pipe with an elastic modulus E=1.5GPa. When the grouting pressure is 2.5MPa, the wall thickness is 2.0mm, and the diameter of the grouting pipe is 10-15mm smaller than the grouting hole.

[0012] Compared with the grouting method using ordinary grouting pipes in the prior art, the utility model provides an adaptive directional grouting system, which has more accurate control of the grouting area, especially has unique advantages in height and direction control, can prevent slurry cross-flow, improve grouting efficiency and reduce grouting costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a plan view of the grouting holes of Example 1;

[0014] Figure 2 is a grouting pipe wall channel arrangement diagram of Example 1;

[0015] Figure 3 Schematic diagram of the grouting pipe in the non-working state and the working state in Example 1, a is the non-working state, and b is the working state.

[0016] In the figure, 1-corner hole, 2-side hole, 3-internal hole, 4-grouting pipe, 5-wall hole,

[0017] 6-evenly distributed channels all around, 7-90 degree channels in three directions, 8-180 degree channels in two directions, 9-90 degree channels in two directions. DETAILED DESCRIPTION

[0018] The utility model provides an adaptive directional grouting system in a typical embodiment, comprising a plurality of grouting holes (such as Figure 1 As shown in the figure), a grouting pipe is arranged in the grouting hole.

[0019] like Figure 2 As shown, a plurality of wall channels are arranged on the wall of the grouting pipe, and the slurry enters a specific stratum through the wall channels during grouting. The types of wall channels on the grouting pipe wall include: (1) evenly distributed channels 6, at least four channels are evenly arranged on the same cross section of the pipe wall; (2) three-way 90-degree channels 7, three channels are arranged on one side of the same cross section of the pipe wall, and the channels are spaced 90 degrees apart; (3) two-way 180-degree channels 8, two channels are symmetrically arranged on the same cross section of the pipe wall; (4) two-way 90-degree channels 9, two channels are arranged on the same cross section of the pipe wall, and the two channels are spaced 90 degrees apart. The wall channels are arranged in a specific direction or at a specific angle, so as to perform directional grouting on strata in different directions.

[0020] The grouting pipe is the key to ensure that the grouting material can be smoothly injected into the foundation. The utility model preferably adopts an adaptive directional grouting pipe with a low elastic modulus, which can produce a certain deformation in the radial direction under the designed grouting pressure, so as to make close contact with the grouting hole and achieve the purpose of directional grouting. The adaptive directional grouting pipe with a low elastic modulus can only expand when the pressure is set to ensure a close fit with the drill hole, realizing directional and precise grouting. After the grouting is stopped, the pressure is reduced and the deformation of the grouting pipe is restored, and other normal construction processes can be carried out.

[0021] During grouting, the grouting working pressure is selected according to the characteristics of the grouting formation. After the grouting pipe is laid, the pressure is applied to the working pressure through the grouting pump. The adaptive directional grouting pipe expands and fits tightly with the grouting hole for directional grouting. After the grouting is completed, the working pressure is reduced, and the adaptive directional grouting pipe returns to its original size and is taken out for continued use. Grouting is the process of injecting grouting materials into the formation. Grouting is carried out by pressure grouting. During the grouting process, the flow rate and pressure of the grouting material need to be strictly controlled to ensure uniform and dense grouting. During the grouting process, due to the low elastic modulus of the pipeline in the grouting section, the pipe diameter expands and fits tightly with the borehole, and grouting is only performed on the formation at a specific height or direction through the hole in the grouting pipe wall.

[0022] Furthermore, the material and size of the adaptive directional grouting pipe are calculated according to formula (1):

[0023] △r = (Pr 2 ) / (2Et) (1)

[0024] Among them, △r is the radial deformation of the grouting pipe wall, P is the liquid pressure in the pipe, r is the outer diameter of the round pipe, E is the elastic modulus of the pipe, and t is the thickness of the pipe wall.

[0025] According to the grouting pressure and the borehole diameter, the elastic modulus of the grouting pipe is determined using the above-mentioned elastic mechanics internal pressure vessel force formula, and then the corresponding material is selected. Under the set grouting pressure, the grouting pipe can fit tightly with the borehole, and the slurry can be precisely grouted into the specific formation through the holes in the grouting pipe wall.

[0026] The grouting system and construction method thereof claimed in the present utility model are described in detail through some specific embodiments. Example 1

[0027] This embodiment provides an embodiment of pressure grouting to reinforce the formation, such as Figure 1 As shown, grouting holes are arranged on the ground in the grouting area, with a diameter of 110 mm. The grouting holes are divided into curtain holes and internal holes 3, and are arranged in a mesh shape. Among them, the curtain holes include corner holes 1 and side holes 2. One row of curtain holes is arranged, and the spacing between curtain holes is 5m; the spacing between internal holes is 10m, and the row spacing is 10m.

[0028] Drilling depth and requirements for grouting area: In order to effectively ensure the filling of the grouting area, the drilling depth of the grouting area should be controlled according to the coordinate range in the treatment design drawing. Drill to 1.0m below the bottom plate of the grouting area. The final hole is determined by the on-site drilling technicians based on the drilling conditions. After the drilling is completed, the hole needs to be cleaned to remove the mud and impurities generated during the drilling process to ensure that the grouting pipe 4 can be lowered and the grouting material can be injected smoothly.

[0029] The front grouting section of the grouting pipe 4 selects an adaptive directional grouting pipe with a low elastic modulus according to the aperture, grouting working pressure and grouting section height, and the remaining rear grouting section for conveying slurry can use an ordinary grouting pipe.

[0030] In this embodiment, the grouting hole diameter is 133 mm, the grouting section height is 100 m, and the grouting working pressure is selected as 2.5 MPa according to the grouting formation characteristics. The grouting area uses a 125 mm polypropylene pipe as an adaptive directional grouting pipe with a wall thickness of 2.0 mm and an elastic modulus of E = 1.32-1.42 GPa. According to formula (1), the deformation value of the grouting pipe 4 reaches 10.5 mm at a working pressure of 2.5 MPa. A pipe wall channel 5 is opened at an interval of 2.0 m on the grouting pipe 4 to facilitate the injection of slurry into the formation.

[0031] The grouting slurry is determined to be cement fly ash slurry with a water-solid ratio of 1:1.0~1:1.3. Cement accounts for 30% of the solid phase and fly ash accounts for 70% of the solid phase.

[0032] In the grouting construction sequence, the outer curtain hole is constructed first, and the surrounding holes of the grouting pipe 4 are constructed as follows: Figure 2 The grouting pipe 4 of the three-way 90-degree duct 7 and the grouting pipe 4 of the two-way 180-degree duct 8 shown in the figure, the four corner holes are as follows Figure 2 The grouting pipe 4 of the two-way 90-degree channel 9 shown in the figure. After forming the curtain, use the following method: Figure 2 The grouting pipe 4 with the uniformly distributed holes 6 shown in the figure is used for grouting the inner hole. When the grouting pipe 4 is not in working state, its diameter is smaller than the borehole to facilitate installation or removal. After the grouting pipe 4 is installed, the grouting pipe 4 expands and fits tightly with the borehole when the working pressure is applied by the grouting pump, and the grouting pipe 4 is oriented and grouting is performed. After the grouting is completed, the working pressure is reduced, and the grouting pipe 4 returns to its original size (such as Figure 3 The grouting pipe 4 can be used continuously after being taken out after the grouting is completed, or it can be arranged in the borehole for one-time use. Example 2

[0033] The difference from Example 1 is that in this embodiment, the grouting hole diameter is 108 mm, the grouting section height is 80 m, and the grouting working pressure is selected as 2.5 MPa according to the characteristics of the grouting formation. The grouting area uses a 90 mm polytetrafluoroethylene tube as an adaptive directional grouting tube with a wall thickness of 2.0 mm and an elastic modulus of E=1.14-1.42 GPa. According to formula (1), the deformation value of the grouting tube 4 reaches 10.5 mm at a working pressure of 2.5 MPa. A pipe wall channel 5 is opened at intervals of 2.0 m on the grouting tube to facilitate the injection of slurry into the formation. Example 3

[0034] The difference from Example 1 is that in this embodiment, the grouting hole diameter is 89 mm, the grouting section height is 80 m, and the grouting working pressure is selected as 2.5 MPa according to the characteristics of the grouting formation. The grouting area uses a 75 mm PVC pipe as an adaptive directional grouting pipe with a wall thickness of 2.0 mm and an elastic modulus of E=1.5 GPa. According to formula (1), the deformation value of the grouting pipe 4 reaches 10.5 mm at a working pressure of 2.5 MPa. A pipe wall channel 5 is opened at intervals of 2.0 m on the grouting pipe to facilitate the injection of slurry into the formation.

[0035] The above shows and describes the basic principle, main features and advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and the specification only describe the principles of the utility model. The utility model may have various changes and improvements without departing from the spirit and scope of the utility model. These changes and improvements fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. An adaptive directional grouting system, comprising a plurality of grouting holes formed in a grouting area, wherein grouting pipes are arranged in the grouting holes, characterized in that: A plurality of wall holes are arranged on the wall of the grouting pipe, and the types of wall holes on the wall of the grouting pipe include: (1) holes evenly distributed all around, at least four holes are evenly arranged on the same cross section of the pipe wall; (2) three-way 90-degree holes, three holes are arranged on one side of the same cross section of the pipe wall, and the holes are spaced 90 degrees apart; (3) two-way 180-degree holes, two holes are symmetrically arranged on the same cross section of the pipe wall; (4) two-way 90-degree holes, two holes are arranged on the same cross section of the pipe wall, and the two holes are spaced 90 degrees apart.

2. The adaptive directional grouting system according to claim 1, characterized in that: The grouting holes include curtain holes and internal holes, and the curtain holes are composed of side holes and corner holes; wherein the side holes use grouting pipes with 90-degree channels in three directions and / or 180-degree channels in two directions, and the corner holes use grouting pipes with 90-degree channels in two directions; the internal holes use grouting pipes with channels evenly distributed all around.

3. The adaptive directional grouting system according to claim 1 or 2, characterized in that: The grouting pipe is a polypropylene pipe with an elastic modulus E=1.32-1.42GPa. When the grouting pressure is 2.5MPa, the wall thickness is 2.0mm, and the diameter of the grouting pipe is 10-15mm smaller than the grouting hole.

4. The adaptive directional grouting system according to claim 1 or 2, characterized in that: The grouting pipe is a polytetrafluoroethylene pipe with an elastic modulus E=1.14-1.42GPa. When the grouting pressure is 2.5MPa, the wall thickness is 2.0mm, and the diameter of the grouting pipe is 10-15mm smaller than the grouting hole.

5. The adaptive directional grouting system according to claim 1 or 2, characterized in that: The grouting pipe is a polyvinyl chloride pipe with an elastic modulus E=1.5 GPa. When the grouting pressure is 2.5 MPa, the wall thickness is 2.0 mm, and the diameter of the grouting pipe is 10-15 mm smaller than the grouting hole.

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