水利与建筑工程学报
水利與建築工程學報
수리여건축공정학보
TECHNIQUE OF SEEPAGE CONTROL
2014年
1期
125-129
,共5页
基坑降水%抽水试验%数值模拟%渗透系数
基坑降水%抽水試驗%數值模擬%滲透繫數
기갱강수%추수시험%수치모의%삼투계수
foundation pit precipitation%pumping test%numerical simulation%permeability coefficient
秦淮河船闸地基土呈典型的二元结构地基形式,由于地质勘察阶段试验井位置选取、已有渗流通道以及影响半径取值等影响因素的存在使得地质勘查阶段渗透系数的计算值与以往的工程实践经验数值差距较大,为了更加准确的描述现场的水文地质条件,为工程降水设计、施工提供准确的水文地质参数,利用抽水试验得到的数据,对现场的地基土建立空间轴对称模型,根据建立的地基土层观测井模型以及远端孔压计所测得的水位对模型扩大分析,反算了地基土的渗透系数,一定程度上降低了影响半径以及经验公式中假设带来的一些误差以及现场基坑范围内管涌通道的影响,通过对比得到地基土的渗透系数都小于地质勘察阶段所得到的渗透系数更加接近工程实践经验数值,对基坑的涌水量进行了更加准确的定量,对工程实践有一定的指导意义。
秦淮河船閘地基土呈典型的二元結構地基形式,由于地質勘察階段試驗井位置選取、已有滲流通道以及影響半徑取值等影響因素的存在使得地質勘查階段滲透繫數的計算值與以往的工程實踐經驗數值差距較大,為瞭更加準確的描述現場的水文地質條件,為工程降水設計、施工提供準確的水文地質參數,利用抽水試驗得到的數據,對現場的地基土建立空間軸對稱模型,根據建立的地基土層觀測井模型以及遠耑孔壓計所測得的水位對模型擴大分析,反算瞭地基土的滲透繫數,一定程度上降低瞭影響半徑以及經驗公式中假設帶來的一些誤差以及現場基坑範圍內管湧通道的影響,通過對比得到地基土的滲透繫數都小于地質勘察階段所得到的滲透繫數更加接近工程實踐經驗數值,對基坑的湧水量進行瞭更加準確的定量,對工程實踐有一定的指導意義。
진회하선갑지기토정전형적이원결구지기형식,유우지질감찰계단시험정위치선취、이유삼류통도이급영향반경취치등영향인소적존재사득지질감사계단삼투계수적계산치여이왕적공정실천경험수치차거교대,위료경가준학적묘술현장적수문지질조건,위공정강수설계、시공제공준학적수문지질삼수,이용추수시험득도적수거,대현장적지기토건립공간축대칭모형,근거건립적지기토층관측정모형이급원단공압계소측득적수위대모형확대분석,반산료지기토적삼투계수,일정정도상강저료영향반경이급경험공식중가설대래적일사오차이급현장기갱범위내관용통도적영향,통과대비득도지기토적삼투계수도소우지질감찰계단소득도적삼투계수경가접근공정실천경험수치,대기갱적용수량진행료경가준학적정량,대공정실천유일정적지도의의。
The foundation soil form in Qinhuai River’s lock area is the typical two-layer structure .As the pilot well loca-tion selection ,existed seepage channels ,as well as radius value selection and other factors make the calculated value of permeability coefficient in geological exploration stage having larger gap compared with the empirical value in past engi-neering practices ,for a more accurate description of the hydrogeologic conditions in site so as to provide accurate hydroge-ological parameters for precipitation design and construction ,the pumping test data is used to establish the space axisym-metric model for the foundation soil in site ,and by using the established foundation soil’s observation well model and the water level from remote bore-pressure meter for the expansion analysis of the model ,the reverse calculation is made for the soil’s permeability coefficient ,so to a certain extent ,some errors from the influencing radius and empirical fomula as well as the effect of the piping channel within the scope of on-site excavation are reduced .The subsoil’s permeability co-efficient obtained by comparing is less than that obtained in the geological exploration stage ,and closer to the empirical value from engineering practices ,thus the pit’s water out flow is made for a more accurate quantification ,which could provide a certain guiding significance for engineering practices .