Construction method for increasing dry auger boring pouring pile bearing capacity

Abstract

The construction process of raising the bearing capacity of auger boring pile includes setting two grouting pipes symmetrically beside the side wall of pile hole, setting reinforcing cage and grouting concrete with concrete pumping agent in 1-1.5 wt% of cement, and pressure grouting cement slurry with concrete pumping agent in 1 wt% of cement and concrete expanding agent in 5 wt% of cement in the pumping pressure of 200-300 kg / sq cm in 8-24 hr after filing until cement slurry overflows from the top end beside the pile. The process can raise the bearing capacity of the pile by over 1 time, reduce the length of the pile, save material, lower cost and reduce construction pollution.

Description

technical field [0001] The invention relates to a construction method of pile foundation engineering, in particular to a construction method for improving the bearing capacity of dry auger bored piles. Background technique [0002] At present, most high-rise buildings use bored pile foundations in order to meet the design bearing capacity and settlement requirements. Dry auger bored pile construction is an economical and environmentally friendly pile foundation construction technology, but it is only suitable for construction above the groundwater level, so the pile length can only be designed above the groundwater level. In recent years, with the continuous improvement of the design height of buildings, the requirements for the bearing capacity of pile foundations have also become higher and higher, and the construction technology of dry auger bored piles has been greatly restricted. In areas where the groundwater level rises, it is almost Be eliminated. In order to incre...

AI Technical Summary

Problems solved by technology

In order to increase the bearing capacity of a single pile and make the pile length above the groundwater level, a construction technique of tamping and expanding piles has appeared. However, this construction method has large vibration and high noise, which not only causes noise pollution to residents, but also causes damage to surrounding buildings on the construction site. damage, so it cannot meet the construction requirements in the urban area

In order to solve the problem of pile formation through the groundwater layer, construction techniques such as drilling and grouting pile formation, jet grouting bottom expansion method, and steel casing retaining wall pouring method have appeared one after another. These methods have a long construction period and a large amount of cement. High project cost, not economical enough

The invention patent with the patent number of 97119826.8 provides a construction technology of rotary drilling mud retaining cast-in-place pile. This construction technology will not only produce mud pollution, but also reduce frictional resistance by the mud skin formed around the pile body

In order to improve the bearing capacity of single piles, the cast-in-place piles designed with this construction technology often have larger diameters and too long pile lengths, making construction difficult and increasing the project cost

In order to solve the above problems, the invention patent with the patent number 00100760.2 provides a post-grouting process for the side of the cast-in-place pile, which effectively improves the frictional resistance of the pile side, and the invention patent with the patent number 200310102269.2 provides a bored cast-in-situ pile The pile side and pile bottom post-grouting construction technology can further improve the pile end bearing capacity on the basis of effectively improving the pile side friction resistance. For the bearing capacity of dry auger bored piles above the groundwater level, the above construction methods must be improved

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