Hole-forming construction technology for high-water-head fine sand layer in civil construction

Abstract

The present invention provides a high-head fine sand layer hole-forming construction process, comprising an inner drill pipe and a casing sleeved on the outer periphery of the inner drill pipe, the inner drill pipe and the casing tail are connected to a transmission shaft to realize synchronous rotation drilling, the inner drill pipe and the transmission shaft are internally connected to form an infusion channel for conveying fluid sealing and waterproofing material, the inlet of the infusion channel is arranged on the transmission shaft, and the inner drill pipe head and the casing head are provided with outlet holes for spraying fluid sealing and waterproofing material, the fluid sealing and waterproofing material is squeezed and infiltrated with sand and soil within a certain range of the working surface under the action of pressure, and then mixed and condensed, so as to achieve the purpose of waterproofing, sealing and compacting the sand and soil on the working surface, prevent the outflow of groundwater and sand and soil, and solve the problem of water and sand gushing in the hole-forming construction of high-head fine sand layer.

Description

Technical Field

[0001] The invention belongs to the technical field of civil construction, and in particular relates to a hole-forming construction process for a high-water-head fine sand layer in civil construction. Background Art

[0002] The soil of the high-head silt-fine sand layer is silt-fine sand, with a large groundwater content and high water pressure. Problems such as water and sand gushing are very likely to occur during the drilling construction, affecting the safety of the foundation pit soil and surrounding buildings (structures). In addition, after drilling, water seepage, water permeability, and hole collapse are likely to occur, making it difficult to meet the design requirements and affecting subsequent construction.

[0003] Most of the existing drilling technologies in civil construction are aimed at impermeable strata or sand layers with low groundwater pressure, and there are few technologies specifically for drilling in high-head fine sand layers. Summary of the invention

[0004] The purpose of the present invention is to provide a high-head fine sand layer hole-forming construction process, the casing and the inner drill pipe are drilled synchronously, and the fluid sealing and water-stopping material is sprayed out through the liquid outlet holes arranged on the inner drill pipe head and the casing head. Under the action of pressure, the fluid sealing and water-stopping material is squeezed and penetrated with the sand and soil within a certain range of the working surface, and then mixed and condensed, so as to achieve the purpose of water-stopping, sealing and compacting the sand and soil on the working surface, prevent the outflow of groundwater and sand, and solve the problem of water and sand gushing in the hole-forming construction of high-head fine sand layer.

[0005] The object of the present invention is achieved in this way: a high-head fine sand layer hole-forming construction process in civil construction, comprising the following steps:

[0006] Step 1: The inner drill pipe is drilled into the soil first, followed by the casing, and then drilled synchronously;

[0007] Step 2: The inner drill pipe head is circumferentially provided with spiral blades and liquid outlet holes are distributed on the side wall. The inner drill pipe is hollow inside to form a liquid infusion channel. The fluid sealing water-stopping material is input into the liquid infusion channel of the inner drill pipe through the inner cavity of the rotating shaft connected to the inner drill pipe through the transmission, and is squeezed out from the liquid outlet holes.

[0008] Step 3: The spiral blade rotates synchronously with the inner drill pipe and pushes the fluid sealing water-stopping material in the forward direction of the drill bit; a space filled with the fluid sealing water-stopping material is formed between the head of the inner drill pipe and the head of the casing;

[0009] Step 4: During the synchronous drilling of the inner drill pipe and the casing, the fluid sealing water-stopping material squeezes, penetrates, mixes and condenses with the water and sand in the soil under pressure, forming a compacted mixed sand layer that is denser than the original sand and soil around the casing and at the front end of the inner drill pipe, thereby preventing water and sand gushing;

[0010] Step 5: After the hole is drilled to the set depth and the mixed sand and soil layer solidifies, the inner drill pipe is removed and the hole-making operation is completed.

[0011] Furthermore, a protective sleeve is installed behind the spiral blade to prevent the fluid sealing water-stopping material from overflowing to the rear end.

[0012] Furthermore, the liquid outlet holes are symmetrically distributed on the side wall of the inner drill pipe, and the top of the inner drill pipe is also provided with a liquid outlet hole.

[0013] Furthermore, the side wall of the sleeve head is also provided with liquid outlet holes.

[0014] Furthermore, each of the liquid outlets is provided with a one-way valve, so that the liquid can only flow out from the inside to the outside.

[0015] Furthermore, an infusion sleeve is rotatably sleeved on the rotating shaft, a filling cavity is formed inside the infusion sleeve, the rotating shaft passes through the filling cavity, and a liquid inlet hole is arranged at the position of the rotating shaft located in the filling cavity; a liquid inlet interface is arranged outside the infusion sleeve to input pressurized fluid sealing and water-stopping material into the filling cavity.

[0016] Furthermore, the liquid inlet interface is connected to a three-way valve.

[0017] Furthermore, an anti-sand surge outer sleeve is installed at the hole mouth, the sleeve is inserted into the anti-sand surge outer sleeve, an annular groove is arranged on the inner wall of the anti-sand surge outer sleeve, and a waterproof plastic bag is arranged in the groove.

[0018] Furthermore, the inner drill pipe is formed by splicing multiple sections, and a one-way valve is provided at the connection between each section.

[0019] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects: the casing and the inner drill pipe are drilled synchronously, and the fluid sealing and water-stopping material is sprayed out through the liquid outlet holes arranged at the head of the inner drill pipe and the head of the casing; the fluid sealing and water-stopping material is squeezed and penetrated with the sand and soil within a certain range of the working surface under the action of pressure, and then mixed and condensed, so as to achieve the purpose of water stopping, sealing and compacting the sand and soil of the working surface, prevent the outflow of groundwater and sand, solve the problem of water and sand gushing in the drilling construction of high head fine sand layer, avoid the leakage of water and sand, ensure the safety of the foundation pit soil and surrounding buildings (structures); because the inner wall of the hole is completely condensed, the hole is sealed and dry, which avoids hole collapse and water seepage, improves the efficiency and quality of drilling, and facilitates subsequent installation operations in the hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the construction site of the hole-forming construction process in the embodiment of the present invention;

[0021] Figure 2 It is a cross-sectional view of the distribution of the liquid outlet holes on the inner drill pipe in an embodiment of the present invention.

[0022] Figure numerals: 1, casing; 2, inner drill pipe; 3, rotating shaft; 4, motor; 5, infusion sleeve; 6, liquid inlet interface; 7, three-way valve; 8, liquid inlet hole; 9, filling cavity; 10, protective cover; 11, anti-sand surge outer casing; 11a, waterproof plastic bag; 12, one-way valve; 13, infusion channel; 14, bearing; a, liquid outlet hole; b, spiral blade. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0024] A construction technology for drilling holes in high-water-head fine sand layers in civil construction, combined with Figure 1-2 , including the following steps:

[0025] Step 1: After locating the hole, chisel the concrete surface of the enclosure structure at the hole, and drill 6 12mm expansion bolts on the concrete surface according to the position of the installation hole of the fixed bottom plate of the sand-gushing outer casing 11; perform a trial installation of the base of the sand-gushing outer casing, and after confirming that the expansion bolts are accurately positioned, install the base, and install the sand-gushing outer casing 11 at the same time. A groove is set on the inner wall of the sand-gushing outer casing 11, and a waterproof plastic bag 11a is set in the groove to prevent water and sand from gushing out through the gap between the casing 1 and the outer casing 11. In order to prevent groundwater and fine sand from gushing out from the gap between the fixed bottom plate of the sand-gushing outer casing and the surface of the enclosure structure, causing water and soil erosion, a sealing cushion layer is added to the gap between the two; a casing 1 is set in the sand-gushing outer casing 11, and an inner drill pipe 2 is set in the casing 1. The inner drill pipe 2 is first drilled into the soil, and the inner drill pipe 2 and the casing 1 are rotated synchronously to squeeze into a hole.

[0026] The casing 1 is used for wall protection and hole drilling, but the inner drill pipe 2 enters the soil slightly ahead of the casing 1. The reciprocating drilling motion of the inner drill pipe 2 produces a squeezing and compacting effect on the soil in front and within a certain range around the casing 1.

[0027] Step 2: spiral blades b are circumferentially installed on the head of the inner drill tube 2 and liquid outlet holes a are distributed on the side wall. The inner drill tube 2 is hollow inside to form an infusion channel 13. The fluid sealing and water-stopping material is input into the infusion channel 13 of the inner drill tube 2 through the inner cavity of the rotating shaft 3 connected to the inner drill tube 2 through a transmission, and is squeezed out from the liquid outlet hole a; the fluid sealing and water-stopping material is pumped into the inner drill tube 2 under the action of a pressure device such as a pressure pump, and ejected through the liquid outlet hole a.

[0028] Step three, the spiral blade b rotates synchronously with the inner drill pipe 2, and pushes the fluid sealing and waterproofing material in the forward direction of the drill bit; a space filled with fluid sealing and waterproofing material is formed between the head of the inner drill pipe 2 and the head of the casing 1; the side wall of the head of the casing 1 is also provided with a liquid outlet a, and the fluid sealing and waterproofing material in the pressure chamber overflows from the gap between the inner drill pipe 2 and the casing 1 and the liquid outlet a on the casing 1, and is mixed with the original soil to form a denser compacted soil to prevent water and sand from gushing. Furthermore, the side wall of the head of the casing 1 is also provided with a liquid outlet a. The liquid outlet a is installed with a one-way valve 12, and the liquid can only flow out from the inside to the outside to prevent the pressurized water in the sand layer from entering the equipment. If the inner drill pipe is a multi-section splicing structure, a one-way valve 12 can also be set at the connection of each section in the inner drill pipe, the purpose of which is to prevent the backflow of the fluid in the pipe if the pressure stops during the operation.

[0029] Step 4: During the synchronous drilling of the inner drill pipe 2 and the casing 1, the fluid sealing water-stopping material under pressure penetrates through the liquid outlet a and is squeezed, infiltrated, mixed and condensed with the water and sand in the soil, forming a mixed sand layer that is denser than the original soil around the casing 1 and at the front end of the inner drill pipe 2, thereby preventing water and sand gushing.

[0030] Step 5: After the hole is drilled to the set depth and the mixed sand layer is solidified, the inner drill pipe 2 is removed and the hole forming operation is completed. If the hole is fully formed, the casing can be removed. If it is not fully formed, the casing can be removed later to prevent the hole from collapsing and affecting subsequent installation.

[0031] Wherein, the inner drill pipe 2 is installed behind the spiral blade b with a protective sleeve 10 to prevent the fluid sealing and waterproof material from overflowing to the rear end.

[0032] The liquid outlet holes a are symmetrically distributed on the side wall of the inner drill pipe 2, and the top of the inner drill pipe 2 is also provided with a liquid outlet hole a. The symmetrically distributed structure makes the equipment run more stably when rotating, avoiding collision between the inner drill pipe 2 and the casing 1.

[0033] Among them, the rotating shaft 3 is rotatably sleeved with an infusion sleeve 5 through a bearing 14, a filling cavity 9 is formed inside the infusion sleeve 5, the rotating shaft 3 passes through the filling cavity 9, and a liquid inlet hole 8 is arranged at the part of the rotating shaft 3 located at the filling cavity 9; a liquid inlet interface 6 is arranged outside the infusion sleeve 5 to input the fluid sealing and water-stopping material with pressure into the filling cavity 9. The liquid inlet interface 6 is connected to a three-way valve 7, one of the interfaces of the three-way valve 7 can be connected to a pressure pump that outputs the fluid sealing and water-stopping material, and the other interface can be selected to connect flushing water or air medium, and when the operation is completed, the residues in the inner drill pipe 2 and the casing 1 can be flushed.

[0034] The fluid sealing water-stopping material in this embodiment can be selected according to specific geological conditions and construction requirements. It can be a rigid cement slurry material or a flexible sealing waterproof agent. As long as these materials are in a fluid state before solidification, they can be applied to the present invention. The factors to be considered in the specific selection of which material to use are the underground water pressure, the drilling speed, and the time and strength of the material solidification. As long as it can solve the problem of water and sand gushing in the drilling construction of the high head fine sand layer, it can be selected.

[0035] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A construction process for forming holes in a high-water-head fine sand layer in civil construction, characterized in that: The following steps are included: Step 1: the inner drill pipe (2) is first drilled into the soil, and the casing (1) is drilled in immediately thereafter, and then drilled synchronously; Step 2: The head of the inner drill pipe (2) is circumferentially provided with spiral blades (b) and has liquid outlet holes (a) distributed on the top and side walls. The head side walls of the casing (1) are also provided with liquid outlet holes (a). The inner part of the inner drill pipe (2) is hollow to form a liquid infusion channel (13). The fluid sealing water-stopping material is input into the liquid infusion channel (13) of the inner drill pipe (2) through the inner cavity of the rotating shaft (3) connected to the inner drill pipe (2) through transmission, and is squeezed out from the liquid outlet holes (a). The liquid outlet holes (a) are all provided with one-way valves (12), so that the liquid can only flow out from the inside to the outside. Step 3: The spiral blade (b) rotates synchronously with the inner drill pipe (2) and pushes the fluid sealing water-stopping material in the forward direction of the drill bit. The inner drill pipe (2) is provided with a protective sleeve (10) behind the spiral blade (b) to prevent the fluid sealing water-stopping material from overflowing to the rear end. A space filled with the fluid sealing water-stopping material is formed between the head of the inner drill pipe (2) and the head of the casing (1); Step 4: During the synchronous drilling process of the inner drill pipe (2) and the casing (1), the fluid sealing water-stopping material, under the action of pressure, penetrates through the outlet hole (a) and squeezes and penetrates with the water and sand in the soil, mixes and condenses, and forms a mixed sand layer that is denser than the original soil around the casing (1) and at the front end of the inner drill pipe (2), thereby preventing water and sand from gushing out; Step 5: After the hole is drilled to a set depth and the mixed sand and soil layer solidifies, the inner drill pipe (2) is removed and the hole-making operation is completed.

2. The hole-forming construction process for high-water-head fine sand layer in civil construction according to claim 1 is characterized by: The liquid outlet holes (a) are symmetrically distributed on the side wall of the inner drill pipe (2).

3. The hole-forming construction process for high-water-head fine sand layer in civil construction according to claim 1 is characterized by: An infusion sleeve (5) is rotatably sleeved on the rotating shaft (3), a filling cavity (9) is formed inside the infusion sleeve (5), the rotating shaft (3) passes through the filling cavity (9), and a liquid inlet hole (8) is provided at a portion of the rotating shaft (3) located in the filling cavity (9); a liquid inlet interface (6) is provided outside the infusion sleeve (5) to input pressurized fluid sealing water-stopping material into the filling cavity (9).

4. The hole-forming construction process for high-water-head fine sand layer in civil construction according to claim 3 is characterized by: The liquid inlet interface (6) is connected to a three-way valve (7).

5. The high-head fine sand layer hole-forming construction process in civil construction according to claim 1 is characterized by: An anti-sand surge outer sleeve (11) is installed at the hole opening, and the sleeve (1) is inserted into the anti-sand surge outer sleeve (11). An annular groove is arranged on the inner wall of the anti-sand surge outer sleeve (11), and a waterproof plastic bag (11a) is arranged in the groove.

6. The construction process for forming holes in a high-water-head fine sand layer in civil engineering construction according to claim 1, characterized in that: The inner drill pipe (2) is formed by splicing together a plurality of sections, and a one-way valve (12) is provided at the connection between each section.

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