CN111636445A - Soil-included stone side slope support construction method - Google Patents

Abstract

The invention belongs to the construction field of hydroelectric engineering technology, and particularly relates to a construction method for an earthwork side slope support. The method comprises the steps of anchor pipe processing, anchor pipe hole measuring and positioning, drilling, anchor pipe installation, grouting and the like, and has the advantages that other supporting forms are incomparable when the construction method of the earth anchor pipe support is adopted, the anchor pipe construction is carried out on special geology, particularly on geology with incomplete rocks or poor rock development, the hole forming efficiency of the anchor hole can be ensured, the construction time is reduced to a certain extent, and the construction efficiency is improved.

Description

Soil-included stone side slope support construction method

Technical Field

The invention belongs to the construction field of hydroelectric engineering technology, and particularly relates to a construction method for an earthwork side slope support.

Background

Under the normal conditions, the water conservancy and hydropower engineering is generally in a deep-mountain canyon, the geographical environment condition is quite severe, the terrain is generally steep, the geological condition is generally poor, and a plurality of places in an engineering construction area have accumulations, collapse accumulation and the like. These all bring great difficulty to the side slope excavation construction. In the slope supporting construction, the main supporting modes include anchor rod supporting, plain concrete spraying, concrete spraying by hanging a reinforcing mesh, anchor cables and the like.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a soil-bound rock side slope support construction method which is used for solving the problem that a hole cannot be formed in a soil-bound rock side slope anchor rod support mode.

In order to achieve the purpose, the invention adopts the following technical scheme: a construction method for supporting a soil-rock slope comprises the following steps:

(1) processing an anchor pipe:

the soil anchor pipe is manufactured by adopting a steel pipe, and is welded or broken according to the construction required length; the diameter of the steel pipe is 48mm, and the wall thickness of the steel pipe is 3 mm;

(2) and (3) measuring and positioning an anchor pipe hole:

setting a measurement control network on a construction site, selecting a total station and a level gauge for measurement and lofting, manually cleaning a drilling working surface before each layer of excavation, measuring the elevation of a rock surface, determining the specific excavation depth of each part by combining the design elevation of foundation excavation, measuring the lofting, discharging the hole positions, angles, depths and the like of each pre-cracked hole and a main blast hole, and controlling the lofting precision to be not more than +/-1 cm;

(3) drilling:

drilling by adopting a ZSTD-150 type anchor pipe machine, and controlling hole position errors, hole depth errors, drilling deviation angles and the like according to the standard requirements;

(4) installing an anchor pipe:

after accumulated water and rock powder in the hole are cleaned up, installing an anchor pipe, and installing in a manual installation mode;

(5) grouting

The anchor pipe adopts PO42.5 cement paste, the water cement ratio can be selected to be 1:1-0.8:1, and the grouting pressure is within 0.3 MPa; and after the soil anchor pipe is grouted, a cement pile column of 30-40cm is generally formed.

Compared with the prior art, the invention has the beneficial effects that: for special geological conditions such as complex side slope geological conditions, thick soil layers, soil and stone inclusion phenomenon in the anchor bolt support and the like, the anchor hole collapse phenomenon can be effectively prevented when the drill rod follows in and exits by adopting a sleeve following construction method, so that the anchor hole is formed, the drill rod cannot be pulled out, and the anchor bolt cannot be poured into the anchor hole; by adopting the construction method of the earth anchor pipe support, when the anchor pipe construction is carried out on special geology, particularly on geology with incomplete rocks or poor rock development, the method has the incomparable advantages of other support forms, can ensure the hole forming efficiency of the anchor hole, reduces the construction time to a certain extent and improves the construction efficiency.

Drawings

Other features, objects and advantages of the present invention will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the present invention.

In the figures, the names corresponding to the reference numbers are 1 and ZSTD-150 novel drilling machines; 2. an anchor tube hole; 3. a slope has been excavated.

Detailed Description

The present invention will be described in further detail with reference to the following examples, which are provided only for illustrating the present invention and are not intended to limit the scope of the present invention.

The method is implemented in the process of excavating the side slope of the engineering of the temple of yellow Tibet of the Black river, and the specific implementation process is as follows:

please refer to fig. 1, which illustrates a construction method of a soil-rock slope support, comprising the following steps:

(1) processing an anchor pipe:

the soil anchor pipe is manufactured by adopting a steel pipe, and is welded or broken according to the construction required length; the diameter of the steel pipe is 48mm, and the wall thickness of the steel pipe is 3 mm;

(2) anchor tube hole 2 measurement positioning:

the method comprises the steps that a measurement control network provided by an EPC part is utilized, the measurement control network is arranged on a construction site, a total station and a level gauge are selected for measurement lofting, before each layer of excavation, a drilling working face is cleaned manually, then the elevation of a rock face is measured, the design elevation of foundation excavation is combined, the specific excavation depth of each part is determined, each pre-cracked hole and main blast hole position, angle, depth and the like need to be released for measurement lofting, and the lofting precision is controlled to be not more than +/-1 cm;

(3) drilling:

drilling by adopting a ZSTD-150 type anchor pipe machine, and controlling hole position errors, hole depth errors, drilling deviation angles and the like according to the standard requirements;

(4) installing an anchor pipe:

after accumulated water and rock powder in the hole are cleaned up, installing an anchor pipe, and installing in a manual installation mode;

(5) grouting

The anchor pipe adopts PO42.5 cement paste, the water cement ratio can be selected to be 1:1-0.8:1, and the grouting pressure is within 0.3 MPa; after grouting, the soil anchor pipe generally forms a cement pile column of 30-40cm, and the combination of the steel pipe and the cement increases the anchoring force of the steel pipe.

In the soil-rock side slope, the construction of the soil anchor pipe mainly adopts an anchor pipe supporting structure, firstly, a steel perforated pipe is driven into the soil, then grouting is carried out, so that slurry permeates into the surrounding soil body to form a composite concretion body, and the composite concretion body is combined with a concrete surface layer to form the supporting structure. Because the soil anchor pipe is required to bear the shearing action in the foundation pit slope rock-soil body, in order to reduce the damage of the grouting holes to the strength of the steel pipe, the grouting holes are spirally arranged.

The main construction difficulty of the construction technology of the anchor pipe of the soil-rock-filled slope soil is pore-forming and anchor pipe installation.

The working principle of the ZSTD-150 type anchor pipe machine is as follows: the piston type air distribution mechanism with the rear cavity always filled with high-pressure air is adopted, an air distribution passage is formed by a sealing ring, and air is distributed by opening and closing an air hole on the piston in the motion process of the piston, so that the reciprocating motion of the piston is realized. And the impact hammer and the stroke support at the end part of the drilling machine are pushed to wedge the anchor pipe and the reinforcing steel bar into the soil layer.

When the impact hammer works, compressed air from the air compressor is injected into the rear cavity through the air inlet in the middle of the air distribution valve, at the moment, the front cavity is communicated with the atmosphere through the front and rear valve holes, the piston moves forwards in an accelerated manner under the action of the pressure difference of the front cavity and the rear cavity, and the distance from the high-pressure air entering the front cavity to the impact of the piston on the cylinder body is short, so that the piston side impacts the cylinder body at a high speed to do work, and stroke action is completed.

During the return stroke, the front cavity pressure is basically equal to the back cavity pressure along with the speed reduction of the piston impacting the cylinder body to zero. Because the pressure-bearing area of the front cavity is larger than that of the rear cavity, the piston does reverse accelerated motion, the pressure of the front cavity is gradually reduced, the piston starts to perform decelerated motion until the speed is zero, one cycle is completed, the acting force of the rear cavity is larger than that of the front cavity, the piston starts to perform the second cycle, and the anchor pipe construction is realized by reciprocating.

The pipe forming machine is composed of a main machine (an air cylinder, an impactor and a hammer head), an operating platform, an air pipe and the like, and is suitable for soil nails (such as angle steel, deformed steel, steel pipes and the like) made of various materials.

After the installation of anchor pipe is accomplished, select the combination of a series of different slip casting pressure and slip casting concentration to through construction quality and economic cost checking calculation, than select under the condition that satisfies construction quality requirement, a set of slip casting pressure and slip casting concentration of manager optimality, the primary design slip casting concentration range is 1:1-0.8:1, and the primary designed grouting pressure is 2.5-3 MPa.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.

Claims (1)

1. A construction method for supporting and protecting a soil-filled stone side slope is characterized by comprising the following steps:

(1) processing an anchor pipe:

the soil anchor pipe is manufactured by adopting a steel pipe, and is welded or broken according to the construction required length; the diameter of the steel pipe is 48mm, and the wall thickness of the steel pipe is 3 mm;

(2) and (3) measuring and positioning an anchor pipe hole:

setting a measurement control network on a construction site, selecting a total station and a level gauge for measurement and lofting, manually cleaning a drilling working surface before each layer of excavation, measuring the elevation of a rock surface, determining the specific excavation depth of each part by combining the design elevation of foundation excavation, measuring the lofting, discharging the hole positions, angles, depths and the like of each pre-cracked hole and a main blast hole, and controlling the lofting precision to be not more than +/-1 cm;

(3) drilling:

drilling by adopting a ZSTD-150 type anchor pipe machine, and controlling hole position errors, hole depth errors, drilling deviation angles and the like according to the standard requirements;

(4) installing an anchor pipe:

after accumulated water and rock powder in the hole are cleaned up, installing an anchor pipe, and installing in a manual installation mode;

(5) grouting

The anchor pipe adopts PO42.5 cement paste, the water cement ratio can be selected to be 1:1-0.8:1, and the grouting pressure is within 0.3 MPa; and after the soil anchor pipe is grouted, a cement pile column of 30-40cm is generally formed.

Images