【作者】 胡静；

【导师】 金建华；

【作者基本信息】 武汉理工大学 ， 市政工程， 2001， 硕士

【摘要】 武汉地区二元结构软土层独特的水文地质特征决定了其深基坑降低地下承压水的特殊性。本文结合以往的研究成果，总结了降水过程中存在的一些问题，主要包括：重要设计参数，如地层渗透性、基坑降水影响半径等，设计中仅从个人经验出发取值，对有限的勘探资料进行取舍和过分地简化。这些局限使设计者不能对地下水进行科学的定量分析，盲目性较大；深基坑降低承压水引起的周边地面沉降的研究虽已取得很大的进展，但是一些主要问题仍未解决，对防渗帷幕的实际挡水效果存在不同看法；对于弱透水层的水文地质参数一直难以准确把握，影响了深基坑降水设计的正确性。 本文主要围绕武汉地区特殊的二元结构软土地层展开研究工作。就深基坑降水工程实际中出现的急待解决的问题进行了大量的试验研究，具体研究内容如下： (一) 在实验室模拟软土地区二元结构地层，进行深基坑降水模型实验，观察地层承压地下水水流运动状态和运动规律。 (二) 利用各种精密测量仪器进行渗流量、渗透系数、水压力等水文地质参数的测定，结合已有的公式和算法，验证各种数据的取值合理性。 (三) 进行防渗帷幕模型试验，观测防渗帷幕的实际挡水效果。 (四) 模拟二元结构土层，进行土样渗流试验，观测水压的变化，研究弱透水层承压水在降水过程中的“滞后和位差”现象和问题。 (五) 利用VB语言开发程序，动态处理实验数据，绘制实验曲线。更多还原

【Abstract】 Unique hydrogeology feature of soft soil two-layer structure in Wuhan city determines particularity of decreasing confined water in deep excavation. Combining achievements in past scientific research, this thesis summarizes some problems in the process of decreasing water ,the problems contains: important parameters such as percolation coefficient, interfering radius etc; designers get parameters from their experience and make their choice of limited prospecting materials too simply, because of the limits, designer can’t make quantitative analysis on groundwater; differences on breakwater effect of setting water-tight screen is still existed, although research evolvement in this field is done; they can’t grasp the hydrogeology parameters accurately in that it influences rightness of designing in deep excavation water-decreasing.The thesis makes model experiment on imminent problems existed in deep excavation water-decreasing project, the concrete contents is as follows:(1) Soft soil two-layer structure stratum is simulated, deep excavation water-decreasing model test is carried on and the law of water motion is observed depending on precise instruments.(2) In order to validate the rightness of the parameters, hydrogeology parameters is measured, such as discharge, percolation coefficient and hydraulic pressure using the precise instruments and existing formula and arithmetic.(3) Water-tight screen model experiment is done and based on it, its actual effect is surveyed.(4) Water flow model experiment is made and hydraulic pressure variation is observed, "the detainment and displacement "of semipervious aquifers in the process of decreasing water is also studied.(5) Based on VB program, the experiment data is handled dynamically and test curves is drew.更多还原