循环荷载下刚性桩对桩承加筋垫层复合地基承载性状影响  

EFFECT OF RIGID PILES ON BEARING PROPERTIES OF COMPOSITE FOUNDATION WITH GEOGRID-REINFORCED CUSHIONS SUPPORTED WITH PILES SUBJECTED TO CYCLIC LOADS

作　　者：李天宝 许家培 刘开富[2] LI Tianbao;XU Jiapei;LIU Kaifu(Zhejiang Guangsha Vocational and Technical University of Construction,Dongyang 322100,China;School of Civil Engineering and Architecture,Zhejiang Sci-Tech University,Hangzhou 310018,China;Linhai Water Group Co.,Ltd.,Zhejiang,Linhai 317000,China)

机构地区：[1]浙江广厦建设职业技术大学,浙江东阳322100 [2]浙江理工大学建筑工程学院,杭州310018 [3]临海市水务集团有限公司,浙江临海317000

出　　处：《工业建筑》2021年第11期137-142,共6页Industrial Construction

基　　金：国家自然科学基金项目(51678619);浙江省自然科学基金项目(LY13E090010)。

摘　　要：刚性桩的设置对加筋垫层复合地基影响的承载性状有明显的影响,但对刚性桩在循环荷载下对桩承加筋垫层复合地基影响的研究尚较少见。通过对多组刚-柔性桩桩承加筋垫层复合地基的模型试验,对比分析柔性桩或刚-柔性桩桩承加筋垫层复合地基在循环荷载下的地基沉降、桩身应变和土工格栅张拉力变化规律。试验结果表明:复合地基沉降随着循环荷载循环次数增加而增大,刚性桩的加入和增加土工格栅层数能有效降低复合地基的沉降,但增加土工格栅层数的效果不如增加刚性桩明显;桩身轴力沿桩深先增大后减小,且随着循环荷载循环次数增加而增大,相同循环荷载条件下,刚性桩的加入可以降低角桩与边桩所承担的荷载;土工格栅的张拉力随着循环荷载循环次数增加而增大,离桩越近,土工格栅张拉力越大,在桩土交界处达到最大值。刚性桩的加入不仅导致土工格栅的张拉力分布发生变化,还提高了土工格栅的张拉力。Rigid pile has obvious effects on bearing properties of composite foundation with reinforced cushions. However, the effect of rigid piles on properties of composite foundation was still in research and the achievements were rarely reported. The changing laws of foundation subsidence, stress of piles and tensile forces of geogrids were analyzed based on some groups of model tests of composite foundation with geogrid-reinforced cushions supported with flexible piles or flexible-rigid piles. The test results showed that subsidence of composite foundation increased with the cycles of cyclic loads. The subsidence of composite foundation could be reduced by addition of rigid piles or of geogrid layers. The effect of adding rigid piles was more obvious than that of adding geogrid layers on reducing subsidence. Axial forces of piles first increased then decreasd along the pile shafts, and the axial forces increased with cycles of cyclic loads. The addition of rigid piles could reduce loads shared by side and corner piles in the same condition of cyclic loads. The tensile forces of geogrids increased with cycles of cyclic loads. The closer to the pile, the greater the tensile forces in geogrids. Tensile forces in geogrids reached the maximum at the junctions of piles and soil. The addition of rigid piles could not only change the distribution of tension forces in geogrids but also increase the tension forces in geogrids.

关 键 词：复合地基 刚-柔性桩 模型试验 循环荷载 地基沉降 土工格栅 

分 类 号：TU470[建筑科学—结构工程]