Construction method of quicklime-modified soil cement pile

Abstract

The invention discloses a construction method of a quicklime-modified soil cement pile and relates to the field of roadbed construction and restoration technology. The construction method of the invention comprises the following steps: (1) punching holes at the interval of 1-1.3 m, wherein adjacent holes are arranged in the form of square or regular triangle; (2) uniformly blending cohesive soil, cement, fly ash, quick-dissolving water glass powder and sodium polyacrylate in proportion so as to prepare a ready-mixed material; (3) preparation of a mixture: uniformly mixing quicklime lump and the ready-mixed material to prepare the mixture; (4) pile-forming compacting: compacting the holes every other rows; and (5) carrying out secondary holes pile-forming work after completion of the first holes pile-forming. The construction method has simple process, and pore-forming can be finished by a conventional machine; the reinforcement effect is good, average moisture content of a soil body is obviously lowered after the treatment, and bearing capacity of the soil body is obviously raised; the method is eco-environment-friendly and low-cost, and the construction cost is 50-70% of the cost of a slip casting method.

Description

technical field [0001] The invention relates to the technical field of pavement foundation construction and repair. Background technique [0002] Due to the inhomogeneity of subgrade filling and the excessive water content of local filling (or foundation), uneven settlement is likely to occur under the action of subgrade pavement self-weight and driving load, which will seriously affect road performance and driving safety. Uneven settlement has also become one of the common quality problems of highway engineering. The commonly used treatment methods for uneven subgrade settlement at home and abroad mainly include grouting method, lime-soil (cement soil) compaction pile method and traditional quicklime pile method. [0003] The grouting method needs to prepare cement into cement slurry, which is transported into the soil body by using water as a carrier. The water-cement ratio of cement slurry in the grouting method is generally 0.8-1.0, while the water-binder ratio require...

AI Technical Summary

Problems solved by technology

[0004] Due to the large hole diameter (greater than 300mm) of the lime-soil (cement-soil) compaction pile method, it is very difficult to form holes in the asphalt pavement or concrete pavement structural layer, and the water content of the subgrade soil in the uneven settlement area is high , the effect of forming holes and piles is poor

[0005] The traditional quicklime pile method uses massive quicklime to add fly ash or directly uses massive quicklime as raw material. In order to improve the compactness of the pile, the fly ash needs to be pre-humidified during the construction process, which causes the quicklime to contact moisture prematurely. Digestion begins before, reducing its water absorption capacity, and the strength of the pile body is low (≤0.5MPa)

The method of directly using quicklime material, because the digested slaked lime will only form a low-strength shell on the soil contact surface around the pile, while the air-hardening material inside the pile—slaked lime is paste-like and has no strength.