阅读说明：本技术 狭小夹缝间小口径降水井的施工方法 (Construction method of small-caliber dewatering well between narrow cracks ) 是由 韩泽亮 杨陆 罗干 万志强 于 2020-12-08 设计创作，主要内容包括：本发明涉及一种狭小夹缝间小口径降水井的施工方法,引孔设备的套筒钻杆一端与套筒钻头连接,另一端通过泥浆管与泥浆泵、泥浆箱连接；引孔设备带动钻杆旋转,通过钻头切割土体向下钻进,同时将泥浆箱中泥浆通过泥浆泵泵送至钻杆内,钻至设计孔深后,将清水通过泥浆泵送至钻杆内,将孔内过稠的泥浆冲稀,然后提出钻杆,下放井管；井管中的滤管、实管采用焊接连接；滤管外包一圈滤网,滤网与井孔内壁间采用滤料回填；实管与井孔内壁间采用粘土回填；粘土回填完成后,采用空压机进行洗井,保证降水井的出水量。本发明的施工方法既可以用在基坑特殊位置打井来降承压水,又可代替传统的大口径承压水观测井,可大大降低了降压井、承压水观测井的施工成本。(The invention relates to a construction method of a small-caliber dewatering well between narrow cracks.A sleeve drill rod of leading hole equipment is connected with a sleeve drill bit at one end, and is connected with a slurry pump and a slurry tank at the other end through a slurry pipe; the hole leading equipment drives the drill rod to rotate, soil is cut by a drill bit to drill downwards, meanwhile, slurry in a slurry tank is pumped into the drill rod through a slurry pump, after the designed hole depth is drilled, clear water is pumped into the drill rod through the slurry, the slurry which is too thick in the hole is diluted, then the drill rod is lifted out, and the well pipe is lowered; the filter tube and the solid tube in the well pipe are connected by welding; a circle of filter screen is wrapped outside the filter pipe, and a filter material is filled between the filter screen and the inner wall of the well hole; backfilling the space between the solid pipe and the inner wall of the well hole with clay; and after the clay is backfilled, washing the well by using an air compressor, and ensuring the water yield of the dewatering well. The construction method of the invention not only can be used for drilling a well at a special position of a foundation pit to reduce the confined water, but also can replace the traditional large-caliber confined water observation well, and can greatly reduce the construction cost of the pressure reduction well and the confined water observation well.)

1. A construction method of a small-caliber dewatering well between narrow cracks is characterized by comprising the following steps:

the first step is as follows: adopting a total station instrument to perform lofting and recheck on the well position, and ensuring that the well position is positioned between underground walls;

the second step is that: moving the leading hole equipment, a sleeve drill rod, a sleeve drill bit, a slurry pump, a slurry pipe and a slurry tank to the well position of a dewatering well, connecting one end of the sleeve drill rod of the leading hole equipment with the sleeve drill bit, connecting the other end of the sleeve drill rod with the slurry pump and the slurry tank through the slurry pipe, aligning the sleeve drill bit to the well position, and then calibrating the flatness of the leading hole machine by adopting a horizontal ruler to ensure that the drill rod is vertically downward;

the third step: starting hole guiding equipment and a slurry pump, wherein the hole guiding equipment drives a drill rod to rotate, cuts the soil body through a sleeve drill bit and drills downwards, and simultaneously, slurry in a slurry tank is pumped into the drill rod through the slurry pump;

the fourth step: after the hole leading equipment drills to the designed hole depth, replacing the slurry in the slurry tank with clean water, pumping the clean water into the drill rod through a slurry pump, flushing the clean water into the bottom of the hole along the drill rod, flushing the thick slurry in the hole to be thin, and then taking out the drill rod;

the fifth step: moving a well pipe, an air compressor, a filter material and clay to the well position of a dewatering well, wherein the well pipe consists of a solid pipe, a filter pipe and a settling pipe, the solid pipe, the filter pipe and the settling pipe are welded and connected, the filter pipe is externally wrapped with a circle of filter screen and wound and fixed by adopting an iron wire, and the well pipe is placed into a hole by matching a crane;

and a sixth step: after the well pipe is lowered to the bottom of the hole, the filter material is backfilled downwards along the outer wall of the well pipe and the inner wall of the well hole to the upper part of the filter pipe section, and the clay is backfilled to the ground elevation after the backfilling of the filter material is finished;

the seventh step: an air pipe of an air compressor is deeply inserted into the bottom of a well casing, one end of a mud pipe is fixed at a wellhead, the air compressor and a mud pump are started, air is blown into the bottom of the pipe through the air pipe, water is filled into the well at the wellhead position through the mud pipe, a water column is formed at the upper part of the well casing, pressurized air at the bottom of the well casing cannot immediately overflow from the wellhead position under the influence of the water column at the upper part, at the moment, the pressurized air breaks through a mud film attached to a filter screen at a filter pipe section and overflows out of the pipe, water in a water-containing layer flows into the well casing at the filter pipe, and water in the water-containing layer circulates; mixing pressurized gas at the bottom of the well pipe, slurry impurities in the well pipe, water in a aquifer and poured water to drive the slurry impurities at the bottom of the hole to move upwards and return to the outside of the well pipe, and repeatedly washing the well until no precipitate or impurity is discharged from the hole;

eighth step: after the well washing of the small-caliber dewatering well is finished, the small-caliber deep well pump is hoisted into the well by adopting a nylon rope, the other end of the nylon rope is fixed at the orifice, and the deepest placement depth of the nylon rope is determined according to the lift of the small-caliber deep well pump.

2. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the diameter of the sleeve drill rod is 219mm, and the diameter of the sleeve drill bit is 219 mm-325 mm.

3. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the inner diameter of a well pipe of the dewatering well is 109-169 mm, and the wall thickness of the well pipe is 2 mm.

4. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the length of the filter pipe section is determined by the thickness of the soil layer, and the length of the settling pipe is 1 m.

5. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the filter tube is externally wound with a circle of filter screen, the filter screen is wound and fixed by iron wires, and the filter screen is a 60-mesh nylon filter screen.

6. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the filter material is quartz sand with the particle size of 0.5-1.2 mm.

7. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the air pressure of the air compressor is 0.7-1.0 MPa.

8. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 1, characterized in that: the type of the small-caliber deep well pump is phi 89 type or phi 110 type slurry pump according to the inner diameter of a well pipe.

9. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 8, characterized in that: the phi 89 type slurry pump is used for a phi 109 type well pipe, the outer diameter is 89mm, the length is 800mm, a water outlet pipe is a 1-inch nylon pipe, and the flow rate is 3m³The delivery lift is 40 m.

10. The construction method of the small-caliber dewatering well between the narrow cracks according to claim 8, characterized in that: the phi 110 type mud pump is used for a phi 169 type well pipe, the outer diameter is 110mm, the length is 1100mm, a water outlet pipe adopts a 1.5-inch nylon pipe, and the flow rate is 6m³The delivery lift is 60 m.

Technical Field

The invention relates to a construction method of deep foundation pit engineering, in particular to a construction method of a small-caliber dewatering well between narrow cracks.

Background

Along with the development of urban construction, building space is smaller and smaller, the depth of a foundation pit is deeper and deeper, the depth of the foundation pit is even more than 40 meters, when the ultra-deep foundation pit is excavated, the risk prevention and control on underground water are particularly important, precipitation of the foundation pit is an indispensable part in deep foundation pit engineering, and the construction of a precipitation well greatly influences the safety of the foundation pit engineering. The building enclosure of the ultra-deep foundation pit usually adopts a rigid underground wall, and in order to ensure the safety of the foundation pit, a circle of flexible underground wall is usually added outside the rigid wall to form two waterproof curtains, a dewatering well is constructed between the two curtains and dewatering is carried out, so that firstly, the risk of confined water inrush to the foundation pit can be prevented, and secondly, the influence on the surrounding environment during the dewatering of the foundation pit can be reduced. In the construction process, the distance between two underground walls is smaller and even less than 1m due to the influence of the construction surrounding environment and the construction site, the minimum aperture of the conventional precipitation well construction is 650mm, the verticality can only reach 1/100, and the underground walls are damaged due to poor hole forming verticality during the construction of the precipitation well, so that the water-resisting performance of the underground walls is greatly reduced. Therefore, a construction method of the small-caliber dewatering well between the narrow cracks needs to be adopted, and the construction problem of the dewatering well between the narrow cracks is solved by selecting a sleeve drill rod and a sleeve drill bit which is specially processed through special hole guiding equipment.

Disclosure of Invention

The invention aims to solve the problem of providing a construction method of a small-aperture dewatering well between narrow cracks, which is an improvement based on the construction method of the existing dewatering well, by selecting special hole leading equipment and a construction process, the minimum hole leading aperture of the equipment can reach 219mm, the hole forming verticality can be ensured to be higher than 1/1000, and the problems that the construction method of the existing dewatering well is low in efficiency and high in manufacturing cost, and the hole forming aperture and the hole forming verticality of the dewatering well cannot meet the requirement of constructing the dewatering well between the narrow cracks due to the limitation of the equipment are solved.

In order to achieve the purpose, the technical scheme of the invention is a construction method of a small-caliber dewatering well between narrow cracks, which comprises the following steps:

the first step is as follows: adopting a total station instrument to perform lofting and recheck on the well position, and ensuring that the well position is positioned between underground walls;

the second step is that: moving the leading hole equipment, a sleeve drill rod, a sleeve drill bit, a slurry pump, a slurry pipe and a slurry tank to the well position of a dewatering well, connecting one end of the sleeve drill rod of the leading hole equipment with the sleeve drill bit, connecting the other end of the sleeve drill rod with the slurry pump and the slurry tank through the slurry pipe, aligning the sleeve drill bit to the well position, and then calibrating the flatness of the leading hole machine by adopting a horizontal ruler to ensure that the drill rod is vertically downward;

the third step: starting hole guiding equipment and a slurry pump, wherein the hole guiding equipment drives a drill rod to rotate, cuts the soil body through a sleeve drill bit and drills downwards, and simultaneously, slurry in a slurry tank is pumped into the drill rod through the slurry pump;

the fourth step: after the hole leading equipment drills to the designed hole depth, replacing the slurry in the slurry tank with clean water, pumping the clean water into the drill rod through a slurry pump, flushing the clean water into the bottom of the hole along the drill rod, flushing the thick slurry in the hole to be thin, and then taking out the drill rod;

the fifth step: moving a well pipe, an air compressor, a filter material and clay to the well position of a dewatering well, wherein the well pipe consists of a solid pipe, a filter pipe and a settling pipe, the solid pipe, the filter pipe and the settling pipe are welded and connected, the filter pipe is externally wrapped with a circle of filter screen and wound and fixed by adopting an iron wire, and the well pipe is placed into a hole by matching a crane;

and a sixth step: after the well pipe is lowered to the bottom of the hole, the filter material is backfilled downwards along the outer wall of the well pipe and the inner wall of the well hole to the upper part of the filter pipe section, and the clay is backfilled to the ground elevation after the backfilling of the filter material is finished;

the seventh step: an air pipe of an air compressor is deeply inserted into the bottom of a well casing, one end of a mud pipe is fixed at a wellhead, the air compressor and a mud pump are started, air is blown into the bottom of the pipe through the air pipe, water is filled into the well at the wellhead position through the mud pipe, a water column is formed at the upper part of the well casing, pressurized air at the bottom of the well casing cannot immediately overflow from the wellhead position under the influence of the water column at the upper part, at the moment, the pressurized air breaks through a mud film attached to a filter screen at a filter pipe section and overflows out of the pipe, water in a water-containing layer flows into the well casing at the filter pipe, and water in the water-containing layer circulates; mixing pressurized gas at the bottom of the well pipe, slurry impurities in the well pipe, water in a aquifer and poured water to drive the slurry impurities at the bottom of the hole to move upwards and return to the outside of the well pipe, and repeatedly washing the well until no precipitate or impurity is discharged from the hole;

eighth step: after the well washing of the small-caliber dewatering well is finished, the small-caliber deep well pump is hoisted into the well by adopting a nylon rope, the other end of the nylon rope is fixed at the orifice, and the deepest placement depth of the nylon rope is determined according to the lift of the small-caliber deep well pump.

Further, the diameter of the sleeve drill rod is 219mm, and the diameter of the sleeve drill bit is 219 mm-325 mm.

Furthermore, the inner diameter of a well pipe of the dewatering well is 109 mm-169 mm, and the wall thickness of the well pipe is 2 mm.

Further, the length of the filter pipe section is determined by the thickness of the soil layer, and the length of the settling pipe is 1 m.

Further, the filter tube is externally wound with a circle of filter screen, the filter screen is wound and fixed by iron wires, and the filter screen is a 60-mesh nylon filter screen.

Furthermore, the filter material is quartz sand with the particle size of 0.5-1.2 mm.

Further, the air pressure of the air compressor is 0.7-1.0 MPa.

Further, the type of the small-caliber deep well pump is phi 89 type or phi 110 type slurry pump according to the inner diameter of the well pipe.

Furthermore, the phi 89 type slurry pump is used for a phi 109 type well pipe, the outer diameter is 89mm, the length is 800mm, a water outlet pipe is a 1-inch nylon pipe, and the flow rate is 3m³The delivery lift is 40 m.

Furthermore, the phi 110 type mud pump is used for a phi 169 type well pipe, the outer diameter is 110mm, the length is 1100mm, a water outlet pipe is a 1.5-inch nylon pipe, and the flow rate is 6m³The delivery lift is 60 m.

The invention has the beneficial effects that:

according to the construction method of the small-caliber dewatering well between the narrow cracks, the sleeve drill rod and the sleeve drill bit which is specially processed are selected through special hole leading equipment, the minimum hole leading aperture can reach 219mm, the hole forming verticality can be guaranteed to be higher than 1/1000, and the construction problem of the dewatering well between the narrow cracks is solved; the method has the advantages of greatly reducing the aperture and the pipe diameter of the dewatering well, reducing investment, greatly reducing cost, along with wide application range, simple and convenient construction, convenient implementation, greatly shortening the construction time of the dewatering well and improving the production efficiency.

Drawings

FIG. 1 is a schematic view of the construction process of the small-bore dewatering well between narrow and small cracks of the present invention;

FIG. 2 is a schematic view of an air compressor well flushing method for a small-caliber dewatering well between narrow cracks according to the present invention;

in the figure: 1. the drilling equipment comprises a hole guiding device 2, a sleeve drill rod 3, a special drill bit 4, a mud box 5, mud 6, a mud pipe 7, an underground wall body 8, an air compressor 9, an air pipe 10, a filter pipe 11, a settling pipe 12 and a solid pipe.

Detailed Description

The invention is further described with reference to the following figures and examples.

As shown in fig. 1 and 2, a construction method of a small-caliber dewatering well between narrow cracks comprises the following steps:

the first step is as follows: adopting a total station instrument to perform lofting and recheck on the well position, and ensuring that the well position is positioned between the underground walls 7;

the second step is that: moving a leading hole device 1, a sleeve drill rod 2, a special drill bit 3, a slurry pump 5, a slurry pipe 6 and a slurry tank 4 to the well position of a dewatering well, connecting one end of the sleeve drill rod 2 of the leading hole device 1 with a special drill bit 3, connecting the other end of the sleeve drill rod 2 with the slurry pump 5 and the slurry tank 4 through the slurry pipe 6, aligning the special drill bit 3 to the well position, and then calibrating the flatness of the leading hole device 1 by adopting a horizontal ruler to ensure that the sleeve drill rod 2 is vertically downward;

the third step: starting the hole guiding equipment 1 and the slurry pump 5, driving the sleeve drill rod 2 to rotate by the hole guiding equipment 1, cutting a soil body through the specially-made drill bit 3, drilling downwards, and simultaneously pumping slurry in the slurry box 4 into the sleeve drill rod 2 through the slurry pump 5;

the fourth step: after the hole leading equipment 1 drills to the designed hole depth, replacing the slurry in the slurry tank 4 with clean water, pumping the clean water into the sleeve drill rod 2 through a slurry pump 5, flushing the clean water into the bottom of the hole along the sleeve drill rod 2, flushing the thick slurry in the hole to be thin, and then taking out the sleeve drill rod 2;

the fifth step: moving a well pipe, an air compressor 8, a filter material and clay to the well position of a dewatering well, wherein the well pipe consists of a solid pipe 12, a filter pipe 10 and a settling pipe 11, the solid pipe 12, the filter pipe 10 and the settling pipe 11 are welded and connected, the filter pipe is externally coated with a circle of filter screen, the filter screen is wound and fixed by adopting an iron wire, and the well pipe is placed into a hole by matching of a crane;

and a sixth step: after the well pipe is lowered to the bottom of the hole, the filter material is backfilled downwards along the outer wall of the well pipe and the inner wall of the well hole to the upper part of the filter pipe section, and the clay is backfilled to the ground elevation after the backfilling of the filter material is finished;

the seventh step: the air compressor 8 is opened, air is blown into the bottom of the pipe through the air pipe 9, the water in the pipe moves up and down, pressurized air is mixed with slurry impurities in the pipe to drive the slurry impurities in the hole to move upwards and return to the outside of the pipe, and the well is repeatedly washed until no sediment is in the hole and the impurities are discharged.

Wherein: before the construction of the dewatering well, a total station is adopted to perform lofting and recheck on the well position, and the well position is determined to be between underground walls.

The hole guiding equipment adopts a sleeve drill rod and a specially processed sleeve drill bit, the diameter of the sleeve drill rod is 219mm, and the diameter of the sleeve drill bit is 219 mm-325 mm.

One end of a sleeve drill rod of the hole guiding equipment is connected with a specially-made drill bit, the other end of the sleeve drill rod of the hole guiding equipment is connected with a slurry pump and a slurry tank through a slurry pipe, the drill bit is aligned to a well position, and then a leveling instrument is adopted to calibrate the flatness of the hole guiding machine, so that the drill rod is ensured to be vertically downward.

The inner diameter of the dewatering well pipe is 109 mm-169 mm, and the wall thickness of the well pipe is 2 mm.

The dewatering well casing consists of upper solid pipe, middle filtering pipe and bottom settling pipe, and the solid pipe, the filtering pipe and the settling pipe are welded together, and have length determined by soil layer thickness and length of 1 m.

The filter tube is wound with a circle of filter screen which is fixed by iron wire, and the filter screen is a 60-mesh nylon filter screen.

And a filter material is backfilled between the filter screen and the inner wall of the well hole, wherein the filter material is quartz sand with the particle size of 0.5-1.2 mm.