Construction method of long spiral extruded cast-in-place pile based on circulating mud retaining wall

Abstract

The invention discloses a long screw extrusion-socketed cast-in-place pile construction method based on circulating slurry breast wall, comprising the steps of first, burying a protective barrel and setting a slurry circulating system that comprises a slurry storage tank and a slurry pumping device, with the upper portion of the protective barrel provided with an overflow hole; second, drilling to form a borehole; third, lifting a drill pipe, and casting a slurry breast wall under high pressure: lifting up the drill pipe, and continuously casting wall supporting slurry from bottom to top from the borehole bottom through the drill pipe by using the slurry pumping device; fourth, lowering a reinforcement cage; fifth, casting concrete underwater and recycling the wall supporting slurry, and recycling the wall supporting slurry discharged through the overflow hole to the slurry storage tank for backup. The method has simple steps, is easy to implement, has high hole-forming quality and good construction effect, and enables the construction of a long screw extrusion-socketed cast-in-place pile to be finished simply and quickly, and by casting the wall supporting slurry from bottom to top from the borehole bottom in a high-pressure casting manner, it is possible to effectively protect the wall and keep the borehole bottom clean with no deposit; the wall supporting slurry is reusable.

Description

technical field [0001] The invention belongs to the technical field of foundation construction, and in particular relates to a construction method of a long spiral extruded cast-in-place pile based on circulating mud retaining walls. Background technique [0002] At present, in foundation projects such as construction, water conservancy, and highways, long spiral hole-forming cast-in-situ piles are widely used due to their advantages of high speed, low noise, no need for mud retaining walls, and low construction costs. But there are following defects and deficiencies in the existing common long spiral hole-forming cast-in-place piles: first, the scope of application is limited, and can only be applied in soil layers such as cohesive soil, silt, and filling soil; When the diameter pebble layer, then drilling is difficult or can't be drilled; Therefore, the soil layer adaptability of existing long spiral hole-forming cast-in-place pile is insufficient, and some areas cannot be...

AI Technical Summary

Problems solved by technology

But there are following defects and deficiencies in the existing common long spiral hole-forming cast-in-place piles: first, the scope of application is limited, and can only be applied in soil layers such as cohesive soil, silt, and filling soil; When the diameter pebble layer, then drilling is difficult or can't be drilled; Therefore, the soil layer adaptability of existing long spiral hole-forming cast-in-place pile is insufficient, and some areas cannot be adopted; Second, the existing long spiral hole-forming pile cannot enter the rock , so the pile end cannot be placed in the soil layer with high bearing capacity after the pile is formed, resulting in practical problems such as low bearing capacity of the single pile; third, after the existing long spiral hole-forming cast-in-situ pile is formed, the soil at the pile end is disturbed, which is easy Form void soil at the bottom of the hole, reduce the resistance of the pile end, thereby affecting the bearing capacity of the single pile; fourth, the quality of the pile body is difficult to guarantee: after the existing long spiral hole-forming cast-in-place pile is holed, when the drill pipe is lifted while pouring, the lifting speed must be Adapt to the pumping speed, and keep more than 0.1 cubic meters of material in the drill pipe, so as to ensure continuous pressure discharge of the drill pipe outlet, otherwise it is easy to cause bad pouring phenomena such as pile breakage, diameter shrinkage, and mud inclusion. Affect the quality of the pile body; Fifth, it is difficult to guarantee the pouring quality: in the construction process of the existing long spiral hole-forming cast-in-place piles, most of them rely on manual observation of the shrinkage and expansion of the concrete delivery pipe and the discharge of the drill pipe vent hole, and according to the observation As a result, the lifting speed is controlled to match the pumping speed. There are sensory differences and experience differences in manual observation, which cannot effectively ensure the quality of grouting; During the drilling process, the drilling tool constantly disturbs the hole wall, and the wall protection mud continuously scours the hole wall, which will generate a large amount of mud and mud skin, and the hole wall is easy to collapse, and it is necessary to clean the hole repeatedly to remove the sediment

Therefore, the traditional pile head treatment and pile cap construction is carried out after concrete pouring and 28-day curing. At this time, the strength of the concrete has reached 98% to 99% of the design strength. Slow, and excavators, tools and other equipment often collide with the pile head during the processing process. Since the pile head is a brittle rigid body after solidification, it is very easy to break once it collides

In addition, when the artificial cylindrical soil mold is used, not only the speed is slow, but also the shape of the cylindrical soil mold is irregular

[0006] It can be seen from the above content that when using the above-mentioned traditional method for pile head treatment and pile cap construction, there are the following main problems: first, the construction efficiency is low: each person can only construct 3 to 5 pile caps per day; second, the cost is high : purely manual production, high labor costs; third, the construction quality is uncontrollable: due to the non-standard operation of the construction personnel, the construction quality of the pile cap cannot be effectively guaranteed; fourth, the construction process is complicated and the labor intensity is high; After the body concrete is solidified, the pile cap construction will be carried out, which will affect the construction period of the cast-in-situ pile

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