Optimization Research For Soft Soils Stabilization In Hangzhou

In Hangzhou, there are large tracts of soft ground high in natural water content and organic matter content, which exhibits high compressibility, low bearing capacity and permeability. Soil stabilization is commonly used to make such ground meet engineering requirements. However, regional differences of stabilization effect can be quite significant if mixing in cement or lime without pertinence. Therefore, it is necessary to develop suitable stabilizers or additives, as well as simple and convenient stabilization strategies for soft ground in Hangzhou to realize intensive treatment. For this, the dissertation mainly carried out the following work:(1) According to characteristics of the soft ground in Hangzhou, influence mechanism of water content and organic matter on stabilization effect was deeply analyzed. Based on this, cement, gypsum, lime and sodium carbonate were selected to improve the engineering properties of soft soil after comprehensively considering stabilization effects, material prices and the convenience of construction.(2) Response surface methodology was employed to determine the additive formula, in which response values were unconfined compressive strength values of stabilized soil with different ages, while independent variables were the contents of gypsum, lime and sodium carbonate. Through analysis of variance, one-factor and mutual-influence, the formula for CX-13was determined.(3) Response surface methodology was introduced into the optimization study of stabilization schemes, in which unconfined compressive strength values of different ages were response values while initial water content, organic matter content, mixing ratios of cement and CX-13were independent variables. As a result, quantitative models of different ages between independent variables and response values were established, based on which mutual-influence and its mechanism were.deeply analyzed.(4) Lagrange multiplier rule was adopted to optimize stabilization strategies. To discuss the analysis procedure, a typical example was provided. And economical applicability of CX-13in practice was further studied by contrast test.