Method for pore-creating of geology with aleurite layer at upper part and middle, slightly weathered siltstone layer at lower part

Abstract

The invention relates to a boring method of geology whose upper portion is a silt layer and lower portion is a moderately weathered and a slightly weathered silt strata, which relates to a construction method of pile foundation boring. The invention aims to solve the problems that prior geology whose upper portion is a silt layer and lower portion is a moderately weathered silt strata or a slightly weathered silt strata uses an electric impact drill to impact to form holes, the boring speed is slow, the efficiency is low, the construction is not done using an auger drill, mud which is used when auger construction is prepared by bentonite or clay, the manhole mud concentration is 1.15-1.25, the manhole mud viscosity is 18-24S, and the moderately weathered and the slightly weathered silt strata which are arranged on the lower portion of the pile foundation is punched by the electric impact drill. Compared with the electric impact drill is solely used to punch, the boring method has faster speed, the upper portion 40mm geology of a pile hole whose length is 50mm and diameter is 1.25m is a silt layer, the lower portion is the moderately weathered and the slightly weathered silt strata,and the boring time is only 4-5 days. Compared with the prior art, the cost of the pile hole is capable of being reduced by 50 percent.

Description

technical field [0001] The invention relates to a pile foundation hole forming construction method. Background technique [0002] With the development of science and technology, with the increasing number of construction projects such as expressways, express railways and urban rail transit, various drilling rigs have been used for geological survey and construction. But still there are shortcomings and deficiencies in the prior art: 1. there is no good pile foundation hole forming method for the geology of moderately weathered sandstone at present. ②For the silt layer in the upper part of the geology and the moderately weathered siltstone or slightly weathered siltstone layer in the lower part, a single percussion drill is used to form holes at present, which has slow hole forming speed, long impact time and low efficiency. Impacting a pile hole with a diameter of 1.25m and a pile length of 50m takes 8 to 10 days to complete, and it is very easy to cause serious inclination...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to solve the problem that the upper part of the existing geology is a silt layer and the lower part is a moderately weathered siltstone layer or a slightly weathered siltstone layer, and the percussion drill is used to impact the hole, and the hole forming speed is slow, the impact time is long, and the efficiency is low; When the pile foundation of excavation and drilling construction encounters moderately weathered siltstone or slightly weathered siltstone, it cannot go on, resulting in the problem of giving up halfway and having to backfill. It provides a geological method with the upper part being the siltstone layer and the lower part being the medium and slightly weathered siltstone layer. Hole forming method