摘要
研究目的:通过对上海虹桥综合交通枢纽虹桥高速铁路站区路基先张法预应力管桩沉桩施工过程中孔隙水压力变化、深层土体位移及桩顶标高的的监测,掌握沉桩过程对预应力管桩桩周土体的挤土效应,研究和采取有效降低挤土效应的具体措施,控制和降低沉桩过程对周围土体结构的影响程度。研究结论:监测发现,距打桩施工区的水平距离越近,受挤土效应的影响越大,超孔隙水压力累计增长量越大;深度越深,超孔隙水压力累计增长量越大。通过对超孔隙水压力及深层土体位移的监测,合理调整了桩基施工的速率和施工工序。管桩的挤土效应比较明显,位移主方向是打桩前进的相反方向。采取提前偏移措施投放桩位,可以减少打桩施工对已完成桩位的影响。在需要控制土体位移量的区域,严格控制打桩速度和打桩方向,同时采取跳打工艺,可以有效降低打桩的挤土效应。
Research purposes： In order to monitor the change of pore water pressure,the displacement of deep soil body and the elevation of the elevation of the pile top in the process of the construction of pretensioned prestrssed pipe pile of roadbed around the Hongqiao Station of Hongqiao integrated transportation hub in Shanghai for well knowing the effect of the process of pile sinking on soil squeezing against the soil body around the pipe pile,the research was done on the specific measures for effectively reducing the soil squeezing effect for the purpose of controlling and reducing the effect of the pile sinking against the surrounding soil structure.Research conclusions：The monitoring result proved that the distance to the pilling area was shorter and the effect of soil squeezing was bigger,the accumulated growth of super pore water pressure was bigger.The depth wass deeper,and the accumulated growth of super pore water pressure was bigger.By the monitoring of the super pore water pressure and the displacement of deep soil body,the construction speed and sequence were adjusted for the pile base construction.The soil squeezing of pipe pile was obvious because the main direction of displacement was the reverse direction to the pilling.Therefore,before the placing of pile,the measure of deviation was taken to minimize the influence of the piling against to the existed pile.In the area where needs to control the soil body dispacement,the piling speed and the direction were strictly controlled,and at the same time,skip-piling technique was used to effectively reduce the soil squeezing by piling.
出处
《铁道工程学报》
EI
北大核心
2010年第9期9-14,共6页
Journal of Railway Engineering Society
关键词
预应力管桩
挤土效应
超孔隙水压力
深层土体位移
prestrssed pipe pile
soil squeezing effect
super pore water pressure
displacement of deep soil
