基于响应面法的盾构施工膨润土改良参数优化

Optimization of bentonite parameters for shield tunneling based on response surface method

为确定福州地铁4号线金牛山—工业路盾构区间强风化花岗岩地层中的膨润土改良最优参数,分别选择膨润土泥浆浓度、掺入比和盾构推进速度3个影响因素,以渣土塌落度、渗透系数和改良成本为响应值。采用中心复合试验设计方法进行了20组试验,分别构建了各响应值的响应面函数。试验结果表明,膨润土泥浆浓度、掺入比和盾构推进速度对渣土改良效果均有较大影响,且各因素之间存在显著交互作用。利用响应面–满意度函数,将渣土改良的3个响应值优化问题转化为单一响应值优化,获得强风化花岗岩地层在不同盾构推进速度下的最优改良参数。该方法科学合理,为金牛山—工业路盾构区间在强风化花岗岩内的高效施工提供了技术保障。

In order to determine the optimal parameters of bentonite improvement in the strongly weathered granite strata in Jinniu Mountain-Gongye Road shield interval of Fuzhou metro line 4,the concentration and mixing ratio of bentonite slurry and advancing speed of shield are selected as the three factors,and the slump,permeability and improvement cost of soils are taken as the response values.The central composite design(CCD)method is used to carry out 20 groups of tests,and the response surface functions of each response value are constructed respectively.The results show the concentration and mixing ratio of bentonite slurry and advancing speed of shield all have great influences on the improvement effect of soils,and there is a significant interaction among these factors.By using the response surface-satisfaction function,the optimization problem of three response values for soil improvement is transformed into that of a single response value,and the optimal improvement parameters of the strongly weathered granite strata under different advancing speeds of shield tunneling are obtained.The proposed method is scientific and reasonable,which provides a technical guarantee for the efficient construction of Jinniu Mountain-Gongye Road shield interval in the strongly weathered granite strata.