Method for strengthening soft foundation through high-pressure jet grouting

Abstract

The invention relates to a method for strengthening a soft foundation through high-pressure jet grouting. The method comprises the following steps that (1) hole sites are arranged in the soft foundation, and a drilling machine is arranged on one hole site; (2) the drilling machine is started, so that a drill rod head rotates and sinks to a design depth, and a real hole site is formed; (3) a jet grouting pipe is inserted in the hole site formed in the step (2), and while the drill rod head sinks, slurry is prepared; (4) when the jet grouting pipe is inserted to the design depth, the jet grouting pipe is rotated and lifted upwards to jet slurry; (5) when the jet grouting pipe is lifted upwards to a design elevation, rotary jet grouting is finished; (6) the jet grouting pipe and the drill rod head are washed cleanly; (7) the drilling machine is moved to the next hole site, the step (2) to the step (6) are repeated, and construction of the next hole site is carried out. Compared with the prior art, the water cement ratio is proper, even stirring can be easily achieved, strengthening quality of the soft foundation is high, strength is high, construction is convenient, manufacturing cost is low, and economic benefits are obvious.

Description

technical field [0001] The invention relates to a method for reinforcing soft soil foundations, in particular to a method for reinforcing soft soil foundations by high-pressure rotary jet grouting. Background technique [0002] With the rapid development of power grid construction, the basic design of transmission lines is related to the safe operation of the line, and more importantly, the investment and comprehensive benefits of the project. At present, the commonly used foundation types are: ① slab foundation: ② bored pile foundation. Among them, the straight column foundation is generally used in areas with good geological conditions, while the cast-in-situ pile foundation is generally used in unfavorable geological areas such as river ponds and soft soils. [0003] In the area of ​​soft soil foundation, the design of the tower foundation in the soft soil foundation area has its particularity because the design of the tower foundation should not only meet the design req...

AI Technical Summary

Problems solved by technology

[0005] (1) The bearing capacity of the foundation of the bearing layer is low, and the shallow covering soil layer is thick, which results in a larger area and deeper foundation burial for the general iron tower shallow foundation (slab foundation) compared with other areas. Deep, the excavation volume of earthwork is large, and the amount of concrete and steel bars is also large

[0006] (2) The width of the slab foundation bottom plate is large, and the foundation is greatly affected by external interference. For example, uneven loading near the tower position or excavation of fish ponds and ditches will cause damage to the stability of the foundation foundation

[0007] (3) For iron towers with a large foundation bearing capacity such as four circuits on the same tower and 500kV lines, if the slab foundation is used, the width of the floor will be very large, and even the slab foundation cannot meet the design requirements, so the entire line must use bored pile foundations

The pile foundation is a deep foundation, and the investment cost is large, and its cost is 2 to 4 times that of the slab foundation, which makes the foundation cost of the entire line very high