A water stop casing suitable for pneumatic down-the-hole hammer trailing pipe drilling and a construction method thereof

Abstract

The application discloses a water-stopping sleeve suitable for pneumatic down-the-hole hammer and pipe drilling and a construction method thereof, and belongs to the water-stopping sleeve field, and specifically comprises the following steps: step S1, eccentric drilling tools of the air down-the-hole hammer are placed into the water-stopping sleeve, the water-stopping sleeve is kept vertical by a suspension method, and a drill rod is connected. The application has the advantages of the prior art, that is, when the pneumatic down-the-hole hammer and pipe drilling process is adopted, the poor water-stopping effect in the shallow part has been a technical problem, the novel water-stopping sleeve can effectively and fully fill the gap between the outer wall of the sleeve and the rock, and the water-stopping effect of the pneumatic down-the-hole hammer and pipe drilling is improved. On the one hand, the connection between the deep groundwater and the shallow groundwater is blocked, and the communication between the layers is avoided; on the other hand, the water head loss of the deep groundwater is prevented, the water head height can be accurately measured, and a good foundation is laid for the later water pumping test, dynamic monitoring and resource quantity evaluation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of water-stopping casing, and particularly relates to a water-stopping casing suitable for pneumatic down-the-hole hammer and pipe drilling and a construction method thereof. BACKGROUND

[0002] The pneumatic down-the-hole hammer and pipe drilling technology is a drilling method combining the speed advantage of air down-the-hole hammer drilling and the advantage of casing wall protection being conducive to the stability of the drilling hole wall. During drilling, the eccentric drill bit is thrown out by the eccentric block when it rotates in one direction, and the diameter of the thrown-out eccentric drill is greater than that of the center drill bit. The casing is simultaneously followed up by the pipe shoe while drilling, and the seamless steel pipe is crucial to the stability of the drilling hole wall of the exploration and mining combined well, the prevention of hole wall spalling and collapse. When the eccentric drill bit drills into the intact formation, after drilling for 0.5-1m, the eccentric block is retracted by reversing, and the eccentric drill is then retrieved from the wall protection casing. In this way, the Quaternary overburden and broken complex formation can be more smoothly penetrated.

[0003] The pneumatic down-the-hole hammer and pipe drilling plays an important role in drought relief, hydrogeological drilling, exploration and test well construction, and fully demonstrates the advantages of efficient well completion and solving the problem of hole wall stability in Quaternary soft overburden and broken rock formation. However, due to the fact that the diameter of the thrown-out eccentric drill is slightly larger than the outer diameter of the casing, when the deep groundwater head is small, surface water and shallow Quaternary pore water will infiltrate through the gap between the casing and the rock formation, which may cause interlayer leakage. When the deep groundwater head is large, the deep groundwater will upwell through the gap between the casing and the rock formation, which often leads to inaccurate determination of the water head height. Therefore, the pneumatic down-the-hole hammer and pipe drilling has poor water-stopping effect with the existing casing. SUMMARY

[0004] The present application aims to provide a water-stopping casing suitable for pneumatic down-the-hole hammer and pipe drilling and a construction method thereof to solve the problems raised in the background.

[0005] To achieve the above object, the present application provides the following technical scheme: A water stop sleeve suitable for pneumatic down-the-hole hammer following pipe drilling and a construction method thereof, comprising the following steps: step S1: placing the eccentric drill of the air down-the-hole hammer into the water stop sleeve, keeping vertical by suspension method, connecting the drill rod, step S2: controlling the air down-the-hole hammer to drill, when the water stop sleeve connected on the pneumatic down-the-hole hammer drills to the position close to the ground surface, connecting another water stop sleeve on the air down-the-hole hammer by left-handed thread or welding, step S3: controlling the air down-the-hole hammer to drill again, when the pneumatic down-the-hole hammer drills to the complete stratum, after drilling 0.5-1m, making the eccentric block retract by reversing, taking the eccentric drill out of the water stop sleeve, and making the water stop sleeve seat on the stable bedrock surface, step S4: installing the guide pipe on the grouting pipe at the upper end of the water stop sleeve exposed outside the ground surface, making one end of the guide pipe communicate with one of the grouting pipes, and the other end of the guide pipe communicate with the pressure grouting machine, and pressing the cement mortar into each grouting pipe by the pressure grouting machine, step S5: during the pressurized grouting process, observing the overflow of the cement mortar of the other grouting pipes and the side wall of the outer pipe and the cement mortar consumption in real time, and stopping the grouting when the cement mortar overflows from the other grouting pipes or the side wall of the outer pipe, step S6: after the pressure grouting is completed, disassembling the guide pipe at the upper end of the water stop sleeve.

[0006] A water stop sleeve suitable for pneumatic down-the-hole hammer following pipe drilling, comprising: a water stop sleeve, which specifically comprises an outer pipe, an inner pipe and grouting pipes, and a plurality of grouting pipes are fixedly connected between the outer pipe and the inner pipe.

[0007] Preferably, the complete stratum in step S3 specifically comprises silty clay, sandy pebble layer, strongly weathered limestone, first medium weathered limestone, dissolved fissure karst water and second medium weathered limestone, the water stop sleeve is communicated with the dissolved fissure karst water through the silty clay, the sandy pebble layer, the strongly weathered limestone and the first medium weathered limestone in sequence, the sandy pebble layer and the strongly weathered limestone are provided with a shallow groundwater layer, the dissolved fissure karst water is provided with a deep groundwater layer, a connecting joint is arranged between every two water stop sleeves, the connecting joint is located at the upper end of the shallow groundwater layer, and the end of the water stop sleeve is located at the lower end of the shallow groundwater layer.

[0008] Preferably, the length of the water stop sleeve is provided in three forms of 1m, 3m and 6m, wherein: the outer pipe wall and the two ends of the inner pipe are lower than a certain height, the height is not less than 10cm, the grouting pipes are tangent to the outer pipe and the inner pipe, and the water stop sleeve adopts an integrated forming process, wherein: the parameters of the water stop sleeve, specifically the outer pipe, the inner pipe and the grouting pipes, are designed as follows: the outer diameter of the sleeve is represented by De, the inner diameter is represented by D, and the wall thickness is represented by δ, wherein the outer diameter of the outer pipe De1 and the wall thickness δ1, the outer diameter of the inner pipe De2 and the wall thickness δ2, the outer diameter of the grouting pipe De3 and the wall thickness δ3, the included angle θ of the center of the circle to the tangent line on both sides of the grouting pipe, and the number N of the grouting pipes.

[0009] ;

[0010] N is an integer;

[0011] ;

[0012] ;

[0013] wherein the cement slurry dosage calculation formula is:

[0014] ,

[0015] wherein D1 is the outer pipe inner diameter, De2 is the inner pipe outer diameter, L is the pipe length, and K is a coefficient of 1.2-1.5.

[0016] Technical effects and advantages of the present application: in the pneumatic down-the-hole hammer follow-up pipe drilling process, the poor shallow water stopping effect has been a technical problem, the use of the novel water stopping sleeve can effectively and fully fill the gap between the outer wall of the sleeve and the rock, and improve the water stopping effect of the pneumatic down-the-hole hammer follow-up pipe drilling. On the one hand, the connection between deep groundwater and shallow groundwater is blocked, and cross-layer communication is avoided; on the other hand, the loss of deep groundwater head is prevented, and the water head height can be accurately determined, which lays a good foundation for later water pumping test, dynamic monitoring and resource quantity evaluation. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a construction structure schematic diagram of the present application;

[0018] Figure 2 is a top view of the pneumatic down-the-hole hammer follow-up pipe of the present application;

[0019] Figure 3 is a sectional view of the pneumatic down-the-hole hammer follow-up pipe of the present application;

[0020] Figure 4 is a partial enlarged view of part A of the present application; Figure 1

[0021] Figure 5 is a partial enlarged view of part B of the present application. Figure 1

[0022] In the figure: 101, silty clay; 102, sandy pebble layer; 103, strongly weathered limestone; 104, first medium weathered limestone; 105, dissolution fissure karst water; 106, second medium weathered limestone; 107, connecting joint; 201, outer pipe; 202, inner pipe; 203, grouting pipe; 204, guide pipe. EMBODIMENT

[0023] ​​The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This invention provides, for example Figures 1-5 The invention relates to a water-stop casing and its construction method for pneumatic down-the-hole hammer drilling, comprising the following steps: Step S1: The eccentric drill bit of the pneumatic down-the-hole hammer is placed into the water-stop casing and kept vertical by suspension. The drill rod is then connected. Step S2: The pneumatic down-the-hole hammer is controlled to drill. When the water-stop casing fitted onto the pneumatic down-the-hole hammer reaches a position close to the ground surface, another water-stop casing is fitted onto the pneumatic down-the-hole hammer and connected by left-hand thread or welding. Step S3: The pneumatic down-the-hole hammer is controlled to drill again. When the pneumatic down-the-hole hammer reaches a complete stratum, it is drilled another 0.5-1m. Then, the eccentric block is retracted by reversing the direction of rotation, and the eccentric drill bit is retrieved from the casing. Step S4: Install a guide pipe 204 on the grouting pipe 203 exposed on the surface of the waterstop sleeve, so that one end of the guide pipe 204 is connected to one of the grouting pipes 203, and the other end of the guide pipe 204 is connected to the grouting machine. The cement mortar is pressed into each grouting pipe 203 by the grouting machine. Step S5: During the pressurized grouting process, observe the overflow of cement mortar from other grouting pipes 203 and the side wall of the outer pipe 201 in real time, as well as the amount of cement mortar used. When cement mortar overflows from other grouting pipes 203 or the side wall of the outer pipe 201, the grouting can be terminated. Step S6: After the grouting is completed, remove the guide pipe 204 at the upper end of the waterstop sleeve.

[0025] A waterstop casing suitable for pneumatic down-the-hole hammer casing drilling includes: a waterstop casing, which is specifically composed of an outer pipe 201, an inner pipe 202, and a grouting pipe 203, with multiple grouting pipes 203 fixedly connected between the outer pipe 201 and the inner pipe 202.

[0026] Specifically, in step S3, the complete stratum specifically includes silty clay 101, sandy pebble layer 102, strongly weathered limestone 103, first moderately weathered limestone 104, dissolution fissure karst water 105, and second moderately weathered limestone 106. The water stop sleeve sequentially passes through the silty clay 101, the sandy pebble layer 102, the strongly weathered limestone 103, the first moderately weathered limestone 104, and the dissolution fissure karst water 105. The sandy pebble layer 102 and the strongly weathered limestone 103 are provided with a shallow groundwater layer. The dissolution fissure karst water 105 is provided with a deep groundwater layer. A connecting seam 107 is arranged between every two water stop sleeves. The connecting seam 107 is located at the upper end of the shallow groundwater layer. The end of the water stop sleeve is located at the lower end of the shallow groundwater layer.

[0027] Specifically, the length of the water stop sleeve is 1 m, 3 m, or 6 m. The outer tube 201 and the inner tube 202 are both lower than a certain height, and the height is not less than 10 cm. The grouting pipe 203 is tangent to the outer tube 201 and the inner tube 202. The water stop sleeve is integrally formed. The parameters of the water stop sleeve, including the outer tube 201, the inner tube 202, and the grouting pipe 203, are designed as follows: the outer diameter is represented by De, the inner diameter is represented by D, and the wall thickness is represented by δ. The outer diameter of the outer tube 201 is De1, and the wall thickness is δ1. The outer diameter of the inner tube 202 is De2, and the wall thickness is δ2. The outer diameter of the grouting pipe 203 is De3, the wall thickness is δ3, the angle between the center and the tangent line of the grouting pipe 203 is θ, and the number of grouting pipes 203 is N.

[0028] ;

[0029] N is an integer;

[0030] ;

[0031] ;

[0032] The amount of cement slurry is calculated by the following formula:

[0033] ,

[0034] where D1 is the inner diameter of the outer tube, De2 is the outer diameter of the inner tube, L is the tube length, and K is a coefficient of 1.2-1.5.

[0035] The wall thicknesses of the outer tube 201, the inner tube 202, and the grouting pipe 203 are designed to be the same, i.e., δ1=δ2=δ3. When the wall thicknesses are 3 mm and 6 mm, respectively, θ is 12°, 15°, and 18°, respectively. The sizes of the water stop sleeve are shown in the following table. More sleeve specifications can be designed according to the above formula.

[0036] Angle θ Number of grouting pipes N Outer diameter of inner pipe De2 (mm) Inner diameter of inner pipe D2 (mm) Wall thickness of inner pipe δ2 (mm) Outer diameter of grouting pipe De3 (mm) Inner diameter of grouting pipe D3 (mm) Wall thickness of grouting pipe δ3 (mm) Outer diameter of outer pipe De1 (mm) Inner diameter of outer pipe D1 (mm) Wall thickness of outer pipe δ1 (mm) 12 30 219 213 3 22.91 16.91 3 273.82 267.82 3 12 30 194 188 3 20.00 14.00 3 243.00 237.00 3 12 30 168 162 3 16.96 10.96 3 210.92 204.92 3 15 24 219 213 3 30.33 24.33 3 288.66 282.66 3 15 24 194 188 3 26.57 20.57 3 256.14 250.14 3 15 24 168 162 3 22.67 16.67 3 222.34 216.34 3 18 20 219 213 3 38.17 32.17 3 304.34 298.34 3 18 20 194 188 3 33.53 27.53 3 270.06 264.06 3 18 20 168 162 3 28.71 22.71 3 234.42 228.42 3 12 30 219 207 6 20.26 8.26 6 277.52 265.52 6 12 30 194 182 6 17.35 5.35 6 246.70 234.70 6 12 30 168 156 6 14.31 2.31 6 214.62 202.62 6 15 24 219 207 6 27.78 15.78 6 292.56 280.56 6 15 24 194 182 6 24.02 12.02 6 260.04 248.04 6 15 24 168 156 6 20.12 8.12 6 226.24 214.24 6 18 20 219 207 6 35.72 23.72 6 308.44 296.44 6 18 20 194 182 6 31.09 19.09 6 274.18 262.18 6 18 20 168 156 6 26.27 14.27 6 238.54 226.54 6

[0037] Finally, it should be noted that the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing embodiments of the present application has been described in detail, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, as long as within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. A water stop sleeve construction method suitable for pneumatic down-the-hole hammer trailing pipe drilling, characterized in that it comprises the following steps: Step S1: placing the eccentric drill of the pneumatic down-the-hole hammer into the water stop sleeve, maintaining verticality by the suspension method, and connecting the drill rod; Step S2: controlling the pneumatic down-the-hole hammer to drill, when the water stop sleeve connected to the pneumatic down-the-hole hammer drills to a position close to the ground surface, connecting another water stop sleeve to the pneumatic down-the-hole hammer through left-handed threads or welding; Step S3: controlling the pneumatic down-the-hole hammer to drill again, when the pneumatic down-the-hole hammer drills to the complete stratum, drilling for 0.5-1 m, then retracting the eccentric block by reversing, and taking out the eccentric drill from the water stop sleeve, so that the water stop sleeve is seated on the stable bedrock surface; Step S4: installing a guide pipe (204) on the grouting pipe (203) at the upper end of the water stop sleeve exposed outside the ground surface, so that one end of the guide pipe (204) communicates with one of the grouting pipes (203), and the other end of the guide pipe (204) communicates with a pressure grouting machine, and the pressure grouting machine is used to press cement mortar into each grouting pipe (203); Step S5: during the pressurized grouting process, observing the overflow of cement mortar from the other grouting pipes (203) and the side wall of the outer pipe (201) and the amount of cement mortar used in real time, and terminating the grouting when the cement mortar overflows from the other grouting pipes (203) or the side wall of the outer pipe (201); Step S6: after the pressure grouting is completed, disassembling the guide pipe (204) at the upper end of the water stop sleeve; The water stop sleeve is specifically composed of an outer pipe (201), an inner pipe (202), and grouting pipes (203), and a plurality of grouting pipes (203) are fixedly connected between the outer pipe (201) and the inner pipe (202); In Step S3, the complete stratum specifically includes silty clay (101), sandy pebble layer (102), strongly weathered limestone (103), first moderately weathered limestone (104), dissolved fissure karst water (105), and second moderately weathered limestone (106), the water stop sleeve communicates with the dissolved fissure karst water (105) through the silty clay (101), the sandy pebble layer (102), the strongly weathered limestone (103), and the first moderately weathered limestone (104), shallow groundwater layers are arranged at the sandy pebble layer (102) and the strongly weathered limestone (103), deep groundwater layers are arranged at the dissolved fissure karst water (105), a connecting joint (107) is arranged between every two water stop sleeves, the connecting joint (107) is located at the upper end of the shallow groundwater layer, and the end of the water stop sleeve is located at the lower end of the shallow groundwater layer; the length of the water stop sleeve is provided in three forms of 1 m, 3 m, and 6 m, and the outer pipe (201) is shorter than the inner pipe (202) by a certain length at both ends, and the length is not less than 10 cm. ​ 2. The water stop casing suitable for pneumatic down-the-hole hammer trailing pipe drilling, applied to a water stop casing construction method suitable for pneumatic down-the-hole hammer trailing pipe drilling according to claim 1, characterized in that: The grouting pipe (203) is tangent to the outer pipe (201) and the inner pipe (202), and the water stop sleeve is integrally formed, wherein: the parameters of the outer pipe (201), the inner pipe (202) and the grouting pipe (203) are designed as follows: the outer diameter of the sleeve is represented by De, the inner diameter is represented by D, and the wall thickness is represented by δ, wherein the outer diameter of the outer pipe (201) is De1, and the wall thickness is δ1; the outer diameter of the inner pipe (202) is De2, and the wall thickness is δ2; the outer diameter of the grouting pipe (203) is De3, the wall thickness is δ3, the included angle θ of the center to the tangent line on both sides of the grouting pipe (203), and the number of the grouting pipe (203) is N, ； N is an integer; ； ； Wherein, the cement slurry dosage calculation formula: ； Wherein D1 is the outer diameter of the pipe, De2 is the inner diameter of the pipe, L is the length of the pipe, and K is a coefficient of 1.2-1.5.

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