Study On The Saturated Loess Foundation Improved By Fly-Ash Cement Mixing Pile

With the continuous improvement of the foundation treatment technology, Develop various forms foundation treatment method of the saturated loess in the highway, railway engineering. This article studies feasibility of fly-ash cement mixing pile treatment the saturated loess foundation from the perspective of ecomomic and reasonable.The study is based on the project of the saturated loess foundation improved of Pu cheng-Wei nan highway, a part of the Huang wei contacting line.According to on-site investigation for the saturated loess, low-lying wetland and the other undesirable geological conditions on this route, Do a lot of laboratory testing to detemine their engineering properties by on-site soil. Provides the basis for the design of foundation treatment plan.Reference on the successful experience of fly-ash cement mixing pile treatment the saturated loess foundation. Do orthogonal experiment with three factors of the total quality of fly-ash cement, the proportion of cement and fly-ash, maintenance time. Analysis of the fly-ash cement specimen strength variation law of various factors by a lot of experimental data. Determine when the total mixing ratio of fly-ash cement is 15%, cement: fly-ash=2:1 (weight ratio), fly-ash cement specimen can satisfy the requirement of the project and rational economic effect. Through theoretical calculation to determine the pile length, diameter, pile spacing, the replacement rate and the other design parameters of fly-ash cement mixing pile treatment the saturated loess foundation.Choose a representative geological section do the site test in order to verify the feasibility of the methods after determine the foundation treatment plan, and detection the strength of single pile and composite foundaion by various methods. Further optimization various parameters of the foundation treatment scheme according to the test results, used to guide the large-scale construction. Embedding the monitoring equipments in composite foundation, monitoring of pile-soil stress ratio and the foundation subsidence. Ananysis the law of development of pile-soil stress ratio and the foundation subsidence by the monitoring the results. According to the law make a engineering evaluation about the effect of fly-ash cement mixing pile treatment the saturated loess foundation. Monitoring and testing results indicate that using fly-ash cement mixing pile treatment the saturated loess foundation can meet the requirements of the intensity and settlement. It is an economic and efficient foundation treatment methods.