真空预压地基出水量现场试验研究及分析  

Field Test and Analysis of Drainage Amount under of the Foundation Vacuum Preloading

作　　者：殷静[1] 刘曙光[1] 董志良[2] 

机构地区：[1]同济大学土木工程学院,上海200092 [2]中交四航工程研究院有限公司,广州510230

出　　处：《地下空间与工程学报》2011年第2期286-290,共5页Chinese Journal of Underground Space and Engineering

基　　金：国家"十一五"科技支撑计划重点项目(2006BAJ27B04);科技部科研院所技术开发研究专项资金(2008EG124222)

摘　　要：通过中山造船基地真空预压软基加固工程的现场试验观测成果,从软土的微观固结机理角度定性分析了真空预压期间加固区内的出水量变化情况,以及地表沉降、地下水位与出水量之间的内在联系。研究结论如下:①真空加固期间的出水量分为两个阶段,加载初期主要为加固区内土体大、中孔隙中的自由水,恒载后以土体的中、微孔隙中能克服自身抗剪强度发生渗流的弱结合水为主。②由于自由水比弱结合水更容易发生渗流,因此抽真空初期的日出水量远大于恒载期的日出水量,但是受到场地地质条件影响,不同区域的出水量多少不均。③总出水量与地下水位降深、地表沉降的关系表现出相似的规律,即加固初期随着总出水量的增大,地下水位降深和地表沉降变化较快,后期变化较慢并逐步趋于稳定。Based on the results of field test in soft foundation of ZhongShan shipbuilding base consolidated by vacuum preloading,the variations of drainage amount in improved area and the relationships between drainage amount and either surface settlement or groundwater level are analyzed from the micro point of consolidation mechanism of soft soil.The conclusions are as follows：（1） The drainage during vacuum preloading could be divided into two stages.One is free water contained in relatively big and medium pores of soil in initially loading period,the other is loosely bound water contained in relatively medium and small pores which could overcome shear strength of themselves to seep in steady loading period.（2）Because free water is much easier to seep than loosely bound water,the drainage amount is much larger in early stage than that in later one.However,the drainage amount is varied with the location due to the influence of geologic conditions.（3）The relationships between total drainage amount and either groundwater level drop or surface settlement are similar,that is,the groundwater level drop and surface settlement variation become rapid with increasing total amount of drainage in early preloading period but slow and steady gradually in later period.

关 键 词：真空预压 出水量 地下水位 地表沉降 结合水 自由水 

分 类 号：O319.56[理学—一般力学与力学基础]