预钻孔措施对静压桩挤土效应的影响分析  

Influence of prebored hole measures on compacting effects of jacked piles

作　　者：罗战友[1] 龚晓南[2] 夏建中[1] 朱向荣[2] 

机构地区：[1]浙江科技学院岩土工程研究所,浙江杭州310023 [2]浙江大学岩土工程研究所,浙江杭州310027

出　　处：《岩土工程学报》2009年第6期846-850,共5页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(50708097);中国博士后科学基金一等资助(20060400317);浙江省高校中青年学科带头人资助计划项目;浙江新世纪151人才项目

摘　　要：桩位处预钻孔是工程中减弱沉桩挤土效应的有效措施之一。根据Drucker-Prager破坏准则及有限变形理论,建立了桩–土相互作用及连续贯入的有限元模型,利用得到的模型模拟了预钻孔措施下沉桩产生的挤土位移场,并和现场实测进行了对比。结果表明,预钻孔的孔径与孔深是影响静压桩挤土效应的重要因素,二者的结合会更有效地减少挤土效应的广度和深度。在同样孔深情况下,随着孔径的增大,所产生的挤土位移相应减小;相同孔径情况下,孔越深产生的挤土效应就越小。Prebored hole is an effective construction measure of reducing compacting effects of jacked piles. An appropriate finite element model is established adopting the Drucker-Prager failure criterion and the finite deformation theory according to the actual process of jacked piles. This model can simulate the interaction of piles and soil and continuous penetration. The displacement fields under the prebored hole measures are studied through the finite element model, and the simulated results are compared with field test ones. The results show that the aperture and hole-depth are important factors for the compacting effects of jacked piles. Combination of the aperture and hole-depth can effectively reduce the compacting effects. With the increment of the aperture, the displacement will decrease under the same hole-depth. With the increment of the hole-depth, the displacement will decrease under the same aperture.

关 键 词：静压桩 挤土效应 预钻孔 数值模拟 现场试验 

分 类 号：TU473[建筑科学—结构工程]