【摘要】 苏通大桥一期试桩采用自平衡静载荷法,结合桩身埋设钢筋计对5根超长大直径试桩进行了试验研究。压浆对桩承载特性的作用有两方面:一是消除工艺因素的影响,恢复土层原有的承载能力;二是提高桩的承载力。压浆对无沉渣情况下承载力计算值的提高幅度为34%～74%,其中端阻力的提高幅度为2%～153%。根据实际测试结果,压浆后桩极限承载力测试值提高幅度为56%～100%,其中总侧阻提高12.39%～52.87%,总端阻提高4.91～25.67倍。桩端阻力所占比例由1.88%～11.68%提高到22.14%～34.67%,桩的承载型态亦发生改变,由摩擦型桩转变为端承摩擦桩。更多还原

【Abstract】 The self-balanced testing method associated with stress gauges buried in shafts was applied to study the bearing behavior of 5 super long-large diameter piles for the 1-stage test project of Sutong bridge. The effects of grouting are (1) to eliminate the influence of technological defects,and recover the bearing capacities of strata,and (2) to improve the bearing capacities of piles. According to test results,the calculation values of ultimate bearing capacity of pile without sedimentation is increased for 34%～74%,and that of pile base is increased for 2%～153%. Compared with test results before grouting,the ultimate bearing capacity of pile is increased for 56%～100% after grouting,the total frictional resistance is increased for 12.39%～52.87% and the total base bearing capacity is increased for 4.91～25.67 times. After grouting,the ratio of base bearing capacity is increased from 1.88%～11.68% to 22.14%～34.67%,so that the bearing behavior of pile is improved greatly.更多还原