Study On Settlement Rule Of Cement Mixing Pile Foundation For Highway In The Yellow River Alluvial Plain

In the Yellow River alluvial plain, soft soil is deep, silt and silty clay are widespread. Severe foundation uniform settlement of freeway would happen without foundation reinforcement. Cement mixing pile reinforcement foundation is a good soft ground treatment. There are many calculation method for the settlement of Cement mixing pile foundation, composite modulus method is a commonly used method. But this method does not consider the influence of pile, often leads to the calculation results is bigger, easy to cause economic waste. Stack preloading and cement mixing pile foundation reinforcement can significantly reduce the post-construction settlement, but the research at home and abroad is less.Establish indoor model test according to the similarity theory. Calculating the working conditions of indoor model test、entity engineering and stack preloading and cement mixing foundation by FLAC3D. Through the settlement results of indoor test and numerical simulation, analyses the law of foundation settlement influenced by pile length、replacement ratio and load. putting forward the optimal coefficients of composite modulus:y=-0.0154x2+0.2701x-0.408,and verifying the rationality of the formula through the field test. Using FLAC3D to analyze the settlement of Stack preloading and cement mixing piles foundation, research the changing rule of the foundation settlement with preloading time, and the law of post-construction settlement influenced by preloading time.This paper bases on "ji nan-Lao Ling" highway, through field test, researches the subsidence rule of cement mixing pile composite foundation with construction time and filling height, putting forward the construction speed and the foundation stability, analyzing the reinforcement effect.This article research results have important guidance and reference significance for the highway cement mixing pile foundation reinforcement in our country.