阅读说明：本技术 山区硬质岩周边不宜扰动环境下桩基成孔方法 (Pile foundation pore-forming method in environment where disturbance is not suitable for surrounding of hard rock in mountainous area ) 是由 何瑞刚 王宏 严定学 司昱 樊海涛 骆大国 王文涛 杜鹏程 匡杨 刘超 彭义 于 2019-11-18 设计创作，主要内容包括：本发明提供山区硬质岩周边不宜扰动环境下桩基成孔方法,适用于山区岩层较坚硬且临近生活区或者周边存在不宜扰动的条件下,能在保证安全前提下,提高桩基成孔效率的,该方法充分利用水磨钻施工工艺成型规则、受干扰小、安全性高的优点,以及爆破成孔成桩快的特点。(The invention provides a pile foundation pore-forming method in a mountainous hard rock surrounding environment which is not easy to disturb, which is suitable for the conditions that a mountainous rock layer is hard and is close to a living area or the surrounding environment is not easy to disturb, and can improve the pile foundation pore-forming efficiency on the premise of ensuring safety.)

1. A pile foundation pore-forming method in a mountainous hard rock surrounding environment which is not suitable for disturbance is characterized by comprising the following steps:

firstly, excavating a pile hole, and drilling a circle of core drilling holes (1) on the inner edge of a pile foundation (2);

taking out the cores in all the drill core holes (1), and further forming a central column (4) in the centers of all the drill core holes (1) to form a blank surface with the surrounding rock wall;

step three, uniformly drilling a plurality of drilling and blasting holes (3) in the center of the central column (4) and the periphery of the central column;

fourthly, filling explosives into the drilling and blasting hole (3);

fifthly, detonating and deslagging the central column (4) to form a primary pile hole (5);

and step six, repeatedly circulating the step one to the step six until the height is 20-50 cm from the bottom of the pile foundation hole, and excavating by using manpower and a pneumatic pick to ensure the integrity of the bed rock at the bottom of the pile.

2. The method for forming the hole in the pile foundation in the environment where the periphery of the hard rock in the mountainous area is not suitable for disturbance according to claim 1, wherein the method comprises the following steps: the diameter of the initial pile foundation (2) selected in the step one is larger than that of the pile foundation which needs to be formed finally, the edges of the drill core holes (1) are arranged in an overlapping mode, and a central column (4) formed in the drill core holes is guaranteed.

3. The method for forming the hole in the pile foundation in the environment where the periphery of the hard rock in the mountainous area is not suitable for disturbance according to claim 1, wherein the method comprises the following steps: in the third step, the depth of the drilling and blasting hole (3) is smaller than that of the core drilling hole (1).

4. The method for forming the hole in the pile foundation in the environment where the periphery of the hard rock in the mountainous area is not suitable for disturbance according to claim 1, wherein the method comprises the following steps: and in the fourth step, explosive loading is controlled according to small explosive loosening blasting, and specific explosive loading is controlled according to the pile diameter of the central column (4) and rock stratum strength.

5. The method for forming the hole in the pile foundation in the environment where the periphery of the hard rock in the mountainous area is not suitable for disturbance according to claim 1, wherein the method comprises the following steps: and fifthly, adopting a small-dose loose blasting method for blasting.

6. The method for forming the hole in the pile foundation in the environment where the periphery of the hard rock in the mountainous area is not suitable for disturbance according to claim 1, wherein the method comprises the following steps: the drilling and blasting holes (3) are distributed in a cross shape.

7. The method for forming the hole in the pile foundation in the environment where the periphery of the hard rock in the mountainous area is not suitable for disturbance according to claim 1, wherein the method comprises the following steps: and in the step one, the core drilling hole (1) is drilled by a water mill drill.

Technical Field

The invention relates to the technical field of hard rock pile foundation pore-forming, in particular to a pile foundation pore-forming method in a hard rock periphery unfavorable disturbance environment in a mountainous area.

Background

At present, blasting pore-forming and water grinding drilling pore-forming construction processes are preferentially selected in the construction of hard rock pile foundations in mountainous areas. The water mill drill construction process has the advantages of regular forming, simple equipment, easiness in operation, no need of blasting, small interference, high safety and the like, but the construction period is long. The blasting hole forming has the advantage of faster pile forming, but the blasting hole forming has high danger and is not suitable for being adopted when the blasting hole forming is close to a building or objects which are not suitable for being disturbed exist at the periphery of the building. Therefore, how to accelerate the hole forming of the pile foundation and reduce the danger in the environment that the periphery of hard rock in the mountainous area is not easy to disturb becomes the difficulty of the hole forming of the pile foundation.

Disclosure of Invention

The invention provides a pile foundation pore-forming method in a mountainous hard rock surrounding environment which is not easy to disturb, which is suitable for the conditions that a mountainous rock layer is hard and is close to a living area or the surrounding environment is not easy to disturb, and can improve the pile foundation pore-forming efficiency on the premise of ensuring safety.

In order to achieve the technical features, the invention is realized as follows: a pile foundation pore-forming method in a mountainous hard rock surrounding environment which is not suitable for disturbance is characterized by comprising the following steps:

firstly, excavating a pile hole, and drilling a circle of core drilling holes on the inner edge of a pile foundation;

taking out the rock cores in all the drill core holes, and further forming a central column in the centers of all the drill core holes so as to form a free face with the surrounding rock wall;

step three, uniformly drilling a plurality of drilling and blasting holes in the center and the periphery of the center column;

fourthly, filling explosives into the drilled blasting holes;

fifthly, detonating and deslagging the central column to form a primary pile hole;

and step six, repeatedly circulating the step one to the step six until the height is 20-50 cm from the bottom of the pile foundation hole, and excavating by using manpower and a pneumatic pick to ensure the integrity of the bed rock at the bottom of the pile.

The diameter of the initial pile foundation selected in the step one is larger than that of the pile foundation to be molded finally, the edges of the drill core holes are arranged in an overlapped mode, and a central column formed in the drill core holes is guaranteed.

And in the third step, the depth of the drilling and blasting hole is less than that of the core drilling hole.

And in the fourth step, explosive loading is controlled according to small explosive loosening blasting, and specific explosive loading is controlled according to the pile diameter of the central column and rock stratum strength.

And fifthly, adopting a small-dose loose blasting method for blasting.

The drilling and blasting holes are distributed in a cross shape.

And in the step one, core drilling is carried out by adopting a water grinding drill.

The invention has the following beneficial effects:

the method is suitable for the hole forming method which is suitable for the conditions that the rock stratum in the mountainous area is hard and is close to a living area or the periphery is not easy to disturb, can improve the hole forming efficiency of the pile foundation on the premise of ensuring safety, and fully utilizes the advantages of regular forming, small interference and high safety of the water mill drilling construction process and the characteristic of quick blasting hole forming. Combine together the two advantage, adopt the water mill to bore during the construction, take out cylindric core along pile foundation aperture inward flange in proper order for the pile foundation is waited to dig out rock mass part and rock wall around and is formed new face the sky face, waits to face the sky face and bores the back of getting, drills, powder charge to facing the core in the sky face, adopts little dose not hard up blasting construction process to get the rock, thereby reaches the purpose that improves pile foundation pore-forming efficiency. The advantages of the water mill drilling method and the shallow hole loosening blasting method are organically combined, and the method has the advantages of regular water mill drilling forming, small interference and high safety, and also has the advantage of rapid hole forming by the blasting method.

Drawings

The invention is further illustrated by the following figures and examples.

FIG. 1 is a plan view of the arrangement of core holes in step one of the present invention.

FIG. 2 is a cross-sectional view of the A-A core hole arrangement of FIG. 1 of the present invention.

Fig. 3 is a plan view of the arrangement of the blast holes drilled in the third step of the invention.

Fig. 4 is a cross-sectional view of the B-B drill-and-blast arrangement of fig. 3 of the present invention.

Fig. 5 is a plan view of the present invention after initiation of the center post in step five.

Fig. 6 is a cross-sectional view of the C-C center post of fig. 5 after initiation of the present invention.

Fig. 7 is a plan view of the arrangement of the secondary core hole drilling construction in step six of the present invention.

Fig. 8 is a cross-sectional view D-D of fig. 7 of the present invention.

In the figure: drilling a core hole 1, a pile foundation 2, a drilling and blasting hole 3, a central column 4 and a preliminary pile hole 5.

Detailed Description

Embodiments of the present invention will be further described with reference to the accompanying drawings.