CN114718055A

CN114718055A - Narrow space mud retaining wall drilling pile construction method

Info

Publication number: CN114718055A
Application number: CN202210408557.3A
Authority: CN
Inventors: 莫刚; 金晨晨; 张贤; 吴丽梅; 陈帆
Original assignee: Ningxia Third Construction Co ltd
Current assignee: Ningxia Third Construction Co ltd
Priority date: 2022-04-19
Filing date: 2022-04-19
Publication date: 2022-07-08

Abstract

A construction method of a slurry retaining wall bored pile in a narrow space is characterized in that a reasonable pile driving sequence is determined according to a drawing and a field environment, each pile position is positioned and lofted by a theodolite and a steel tape according to design requirements, and a pile position line is well lofted to determine a pile foundation point position; assembling drilling equipment and performing drilling construction; inserting the steel pipe pile into the drill hole, and performing grouting construction after elevation measurement and adjustment; the invention utilizes the mechanical rotation principle, adopts the design of combining a pistol drill and a gear driving group, and drives a drill rod with a spiral drill bit arranged at the head part to drill; the construction process does not occupy the field, and the transfer is convenient; the construction method is simple to use, convenient to maintain, capable of saving construction cost, capable of improving efficiency, high in construction speed and good in use convenience. The mud is matched to protect the wall of the pile body, the drilling process is lubricated, and the inner side pressure and the outer side pressure guarantee the stability of the pile body when the pile hole is drilled and taken in a balanced mode. The method is suitable for the engineering operation of the bored pile with complex side environment conditions of the foundation pit and small working surface.

Description

Narrow space mud retaining wall drilling pile construction method

Technical Field

The invention relates to the technical field of bored pile construction, in particular to a construction method of a slurry retaining wall bored pile in a narrow space.

Background

In the construction process of developing a 'Xixia gold wave residential quarter 36# building', a supporting structure of a steel pipe pile and a prestressed anchor cable is adopted in the foundation pit supporting design. As the west side is adjacent to the original 35# residential building, the south side is adjacent to the school enclosure, the east side is adjacent to the original pedestrian crossing (4 m), the construction operation field is 35 multiplied by 40m, the construction field is narrow and small, the construction working surface is limited, and the traditional piling machinery cannot advance to be close to the situation due to the narrow field, so that drilling and piling are realized in the limited working area, and the traditional mud retaining wall construction method cannot work.

Disclosure of Invention

In order to solve the technical problems in the prior art, there is a need for a method for constructing a slurry retaining wall bored pile in a narrow space.

A construction method of a slurry retaining wall drilling pile in a narrow space comprises the following steps:

determining the position of a pile foundation point: determining a reasonable piling sequence according to a drawing and a field environment, positioning and lofting each pile position according to design requirements by using a theodolite and a steel tape, and well setting the pile position line;

assembling and drilling the drilling equipment: after the drilling equipment is assembled, the drilling equipment needs to be subjected to trial operation, and normal drilling construction can be started under the condition that the drilling equipment is not abnormal and the drilling is normal;

and (3) steel pipe pile lowering: inserting the steel pipe pile into the drill hole, wherein the diameter of the drill hole is slightly larger than that of the steel pipe pile, bentonite slurry is stored in the hole, the steel pipe naturally sinks to the bottom of the pile, and the construction is completed after elevation measurement and adjustment;

grouting: before steel pipe is put into a hole, the pipe wall is perforated to serve as grouting holes, the vertical distance is 1000mm, the holes are arranged in a quincunx mode, pure cement slurry is adopted as grouting liquid, the grouting liquid is controlled to be 2-3 Mpa, the water-cement ratio is 0.50-0.55, triethanolamine accounting for 0.1% of the weight of the cement and salt accounting for 0.2% of the weight of the cement are added into the cement slurry, and therefore the grouting performance is improved and the early strength is increased.

Preferably, the drilling equipment comprises a holding disc, a water inlet pipe, a pistol drill, rotary joints, gear driving groups, drill rods, drill bits and limiting clamps, wherein the rotary joints are installed on the holding disc, the upper ends of the rotary joints are located above the holding disc, the inlet ends of the rotary joints are communicated with the water inlet pipe, the lower ends of the rotary joints are connected with the drill rods, the number of the drill rods is at least two, the drill rods are sequentially in threaded connection, the drill bits are in threaded connection with the lower end portions of the drill rods, the limiting clamps are fixed on the ground and used for limiting deviation and shaking of the drill rods, the gear driving groups are sleeved on the rotary joints, and the output ends of the pistol drill are fixedly connected with the input ends of the gear driving groups and used for driving the gear driving groups to transmit power to the drill rods and drive the drill rods to rotate.

Preferably, the limiting clamp is of a disc shape, and a cross-shaped sharp nail vertical to the ground is arranged below the limiting clamp.

Preferably, when drilling with the drilling apparatus,

firstly, determining the central point of the position of a steel pipe pile of a foundation pit, aligning the central point of a pile foundation tool bit with the central point of the steel pipe pile, starting a pistol drill, and vertically drilling the tool bit into a soil layer;

when the drilling depth reaches 300mm for the first time, the rotary joint is separated from the drill rod, then the limiting clamp is sleeved in the drill rod, the limiting clamp is hammered into the ground by a hammer, and the drill rod cannot generate excessive deviation and shaking due to the limitation of the limiting clamp, so that the perpendicularity of a pile body and the consistency of the section of the pile body are ensured;

when the tail of the first drill rod is drilled to be 200mm away from the ground, the connection between the drill rod and the rotary joint is cancelled, the second drill rod and the first drill rod are screwed tightly, then the rotary joint is connected with the second drill rod, and drilling is continued; according to the depth requirement of the steel pipe pile, repeatedly connecting drill rods and drilling a pile body to the designed depth;

during the drilling process of the pile body, digging a slurry pool beside the pile body, wherein the volume of the slurry pool is larger than that of the pile body so as to ensure that slurry after the drilling of the steel pipe pile is finished can be stored in the slurry pool in a centralized manner; and a water pump is placed in the slurry pool, the water pump is connected to a rotary joint on the drilling equipment through a water inlet pipe, the water pump is connected with the drill rod through the rotary joint, and slurry flows into the drill hole from the bottom of the first drill rod.

Preferably, when drilling is started, a first drill rod is firstly erected on a drilling point by one person, then the gear driving group and the drill rod are in threaded connection by the other person, then the pile body is drilled, and the holding disc needs to be held in the drilling process, so that the whole equipment is prevented from rotating together.

Preferably, in the step of determining the position of the pile foundation, when the pile foundation is positioned and lofted,

before construction, a level gauge is used for measuring the elevation of a construction site, and the average value is calculated and used as the elevation of a drilling construction terrace, so that the hole forming depth is controlled;

and (4) carrying out pile position positioning lofting by utilizing a theodolite and a steel tape according to the control axis.

Preferably, in the step of determining the position of the pile foundation, when the pile foundation is placed on the pile foundation, the pile foundation line is led out from each axis, the allowable deviation is 1cm, a triangular mark is made at the center of the pile foundation by red paint, and a control circle is drawn by taking the mark as the center of a circle and the radius of the pile as the radius.

According to the technical scheme, the construction method of the slurry retaining wall drilled pile in the narrow space, provided by the invention, adopts the design of combining the pistol drill and the gear driving set by utilizing the mechanical rotation principle to drive the drill rod with the spiral drill bit arranged at the head part to drill; the construction process does not occupy the field, and the transfer is convenient; the construction method is simple to use, convenient to maintain, capable of saving construction cost, capable of improving efficiency, high in construction speed and good in use convenience. The mud is matched to protect the wall of the pile body, the drilling process is lubricated, and the inner side pressure and the outer side pressure guarantee the stability of the pile body when the pile hole is drilled and taken in a balanced mode. The method is suitable for the engineering operation of the bored pile with a small working surface, which is used for the complicated side environment condition of the foundation pit.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic structural view of the drilling apparatus of the present invention.

Fig. 2 is a schematic top view of the structure of fig. 1.

In the figure: the device comprises a holding disc 1, a water inlet pipe 2, a pistol drill 3, a rotary joint 4, a gear driving group 5, a drill rod 6, a drill bit 7, a limiting clamp 8, a cross spike 9 and a handle 10.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "upper", "middle", "outer", "inner", "lower", and the like, indicate orientations or positional relationships, are used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the referenced components or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

determining the position of a pile foundation point: determining a reasonable piling sequence according to a drawing and a field environment, positioning and lofting each pile position according to design requirements by using a theodolite and a steel tape, and well setting the pile position line; before construction, a level gauge is used for measuring the elevation of a construction site, and the average value is calculated and used as the elevation of a drilling construction terrace, so that the hole forming depth is controlled; and (4) carrying out pile position positioning lofting by utilizing a theodolite and a steel tape according to the control axis. When the pile position line is placed on the pile foundation, the pile position line is led out from each axis, the allowable deviation is 1cm, a triangular mark is made at the central point of the pile position by red paint, and a control circle is drawn by taking the mark as the center of a circle and the radius of the pile as the radius.

Assembling and drilling the drilling equipment: after the drilling equipment is assembled, the drilling equipment needs to be operated in a trial mode, and normal drilling construction can be started under the condition that the drilling equipment is not abnormal and the drilling is normal;

wherein, drilling equipment includes holding the dish 1, the inlet tube 2, pistol drill 3, rotary joint 4, gear drive group 5, drilling rod 6, drill bit 7, spacing card 8, be provided with handle 10 on holding the dish 1, can make things convenient for the workman to carry or, it is stable to keep holding dish 1, rotary joint 4 installs on holding the dish 1, rotary joint 4's upper end is located holds dish 1 top, rotary joint 4's entry end and inlet tube 2 intercommunication, rotary joint 4's lower extreme is connected with drilling rod 6, drilling rod 6 has two at least, threaded connection in proper order between every drilling rod 6, lower tip threaded connection at drilling rod 6 has drill bit 7, drilling rod 6 is diameter phi 32 steel pipe, length 2.03m, head and the tail mantle fiber, adopt the mode of screw thread connection. The limiting clamp 8 is fixed on the ground and used for limiting the deviation and shaking of the drill rod 6, the gear driving group 5 is sleeved on the rotary joint 4, the output end of the pistol drill 3 is fixedly connected with the input end of the gear driving group 5 and used for driving the gear driving group 5 to transmit power to the drill rod 6 and drive the drill rod 6 to rotate. The limiting clamp 8 is of a disc shape, and a cross-shaped sharp nail 9 vertical to the ground is arranged below the limiting clamp 8.

When drilling is carried out by using drilling equipment, firstly, the central point of the position of the steel pipe pile of the foundation pit is determined, then the central point of the pile foundation tool bit is aligned to the central point of the steel pipe pile, the pistol drill 3 is started, and the tool bit is vertically drilled into the soil layer; when drilling begins, a first drill rod 6 is firstly erected on a drilling point by one person, then the gear driving group 5 and the drill rod 6 are in threaded connection by the other person, then the pile body is drilled, and the holding disc 1 needs to be held in the drilling process, so that the whole equipment is prevented from rotating together.

When the drilling depth reaches 300mm for the first time, the rotary joint 4 is separated from the drill rod 6, then the limiting clamp 8 is sleeved into the drill rod 6, the limiting clamp 8 is hammered into the ground by a hammer, and the drill rod 6 cannot generate excessive deviation and shaking due to the limitation of the limiting clamp 8, so that the perpendicularity of a pile body and the consistency of the section of the pile body are ensured;

when the tail of the first drill rod 6 is drilled to be 200mm away from the ground, the connection between the drill rod 6 and the rotary joint 4 is cancelled, the second drill rod 6 and the first drill rod 6 are screwed, the rotary joint 4 and the second drill rod 6 are connected, and drilling is continued; according to the depth requirement of the steel pipe pile, repeatedly connecting the drill rods 6 and drilling the pile body to the designed depth;

during the drilling process of the pile body, digging a slurry pool beside the pile body, wherein the volume of the slurry pool is larger than that of the pile body so as to ensure that slurry after the drilling of the steel pipe pile is finished can be stored in the slurry pool in a centralized manner; and (3) putting a water pump into the slurry pool, connecting the water pump to a rotary joint 4 on the drilling equipment through a water inlet pipe 2, connecting a drill rod 6 through the rotary joint 4, and enabling the slurry to flow into the drill hole from the bottom of the first drill rod 6.

The water pump and the pistol drill 3 have a linkage function, and the water pump can be started simultaneously with the opening of the pistol drill 3, so that reasonable extraction and use of slurry are ensured; the slurry has certain density, generates certain hydrostatic pressure in the hole, is equivalent to a liquid support, and can stabilize the soil wall and prevent hole collapse. In addition, the slurry can also seep and fill the gaps in different soil layers in the drilled hole tightly, so that a layer of compact mud skin with low water permeability is formed, the water leakage of the inner wall of the hole is avoided, a certain water pressure is kept in the hole, and the stability of the hole wall is favorably maintained. The slurry also has high viscosity, and the soil, stone and slag chips which are cut and crushed can be suspended by circulating the slurry, and the slurry is discharged out of the hole along with the slurry to play the roles of carrying and discharging the slag. Meanwhile, slurry is circularly used as flushing liquid, so that the drill bit has cooling and lubricating effects, the abrasion of the drill bit 7 is reduced, and the drilling is facilitated.

And (3) steel pipe pile placement: inserting the steel pipe pile into the drill hole, wherein the diameter of the drill hole is slightly larger than that of the steel pipe pile, bentonite slurry is stored in the hole, the steel pipe naturally sinks to the bottom of the pile, and the construction is completed after elevation measurement and adjustment;

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims

1. A construction method of a slurry dado bored pile in a narrow space is characterized in that: the method comprises the following steps:

grouting: before the steel pipe is drilled into a hole, the pipe wall is perforated to be used as a grouting hole, the thickness of the perforated hole is 10mm, the vertical distance is 1000mm, the quincunx arrangement is adopted, pure cement slurry is adopted as grouting slurry, the grouting slurry is controlled to be 2-3 Mpa, the water cement ratio is 0.50-0.55, triethanolamine with the weight of 0.1% of cement and salt with the weight of 0.2% of cement are added into the cement slurry, and therefore the grouting performance is improved and the early strength is increased.

2. The narrow space mud dado bored pile construction method according to claim 1, characterized in that: the drilling equipment comprises a holding disc, a water inlet pipe, a pistol drill, rotary joints, a gear driving group, drill rods, drill bits and limiting clamps, wherein the rotary joints are installed on the holding disc, the upper ends of the rotary joints are located above the holding disc, the inlet ends of the rotary joints are communicated with the water inlet pipe, the lower ends of the rotary joints are connected with the drill rods, the drill rods are sequentially in threaded connection, the drill bits are in threaded connection with the lower end portions of the drill rods, the limiting clamps are fixed on the ground and used for limiting deviation and shaking of the drill rods, the gear driving group is sleeved on the rotary joints, the output ends of the pistol drill are fixedly connected with the input ends of the gear driving group and used for driving the gear driving group to transmit power to the drill rods and drive the drill rods to rotate.

3. The narrow space mud dado bored pile construction method according to claim 2, characterized in that: the limiting clamp is of a disc shape, and a cross-shaped sharp nail vertical to the ground is arranged below the limiting clamp.

4. The narrow space mud dado bored pile construction method according to claim 3, characterized in that: when the drilling is performed by means of the drilling equipment,

firstly, determining the central point of the position of the steel pipe pile of the foundation pit, then aligning the central point of a pile foundation tool bit with the central point of the steel pipe pile, starting a pistol drill, and vertically drilling the tool bit into a soil layer;

5. The narrow space mud dado bored pile construction method according to claim 4, characterized in that: when drilling is started, a first drill rod is firstly erected on a drilling point by one person, then the gear driving group and the drill rod are in threaded connection by the other person, then the pile body is drilled, and the holding disc needs to be held in the drilling process, so that the whole equipment is prevented from rotating together.

6. The narrow space mud dado bored pile construction method according to claim 1, characterized in that: in the step of determining the position of the pile foundation, when positioning and lofting the pile foundation,

7. The narrow space mud dado bored pile construction method according to claim 6, characterized in that: in the step of determining the position of the pile foundation, when the pile position line is placed on the pile foundation, the pile position line is led out from each axis, the allowable deviation is 1cm, a triangular mark is made at the center of the pile position by red paint, and a control circle is drawn by taking the mark as the center of a circle and the radius of the pile as the radius.