粘土中吸力锚沉贯阻力与土塞形成试验研究  

An experimental investigation of insertion resistance and soil heave during caisson installation in soft clay

作　　者：国振[1] 王立忠[1] 袁峰[1] 

机构地区：[1]浙江大学建筑工程学院,浙江杭州310058

出　　处：《海洋工程》2011年第1期9-17,共9页The Ocean Engineering

基　　金：国家自然科学基金资助项目(50779061)

摘　　要：针对粘土中吸力锚沉贯的两个关键性问题———沉贯阻力和土塞形成过程,在自行研制的试验平台上进行一系列吸力锚沉贯室内模型试验。试验结果表明,负压抽吸对筒壁内部土体的影响较大,而对外侧土体的影响很小;由压力沉贯向吸力沉贯转换后,土体阻力会先降低,再随着沉贯的进行逐渐增大,并超过采用压贯方式的土体阻力;前期压贯深度的变化带来了不同的内部泥面下陷,这对吸力沉贯开始阶段的土塞发展影响不大,当土塞加速隆起后,压贯越深的情况土塞发展越迅速;在粘土中进行吸力沉贯时,API规范对最大容许吸力估算较为准确,但是需提供比API规范更大的沉贯吸力才能保持沉贯的进行,而且沉贯过程中土塞的高度大于由于筒裙下插置换土体所带来的高度。To investigate the insertion resistance and soil heave during caisson installation in soft clay,a series of model tests are carried out on the novel self-made test platform.Based on these test results,some useful conclusions are drawn： the inner suction pressure mainly affects the soil mass inside the caisson,and it has little influence on the outside soil;while transferred from dead weight insertion to suction insertion,the suction caisson will encounter a lower soil resistance,but the resistance will increase quickly with further insertion and exceed the resistance during dead weight insertion;different insertion depths by dead weight can affect the development of soil heave;different insertion depths will result in different sinking depths of inner soil surface,which has little influence on the development of soil heave at the beginning state of suction insertion,but after the soil heave is accelerated,the development of soil heave is more rapid in the case with deeper former insertion depth;while the caisson is inserted by suction pressure,the actual allowable suction is close to the suction calculated by API method,but larger suction is required for the caisson insertion than the suction by API method,and the height of soil heave is larger than the heave height caused by the soil displaced by the cross sectional area of the anchor.

关 键 词：粘土 吸力锚 沉贯阻力 土塞 内部吸力 

分 类 号：P75[天文地球—海洋科学]