既有桩基对盾构施工参数的影响研究

发布时间：2018-05-04 05:27

本文选题：支护压力 + 注浆压力　；参考：《岩土工程学报》2016年09期

【摘要】：盾构隧道施工邻近桥梁桩基已成为目前研究的热点问题。针对盾构施工参数取值在工程中的应用价值,利用三维弹塑性有限元分析了桩基引起地层的竖向附加应力,反推出了Geedes式中的桩端阻力、桩侧阻力分担桩顶荷载的比例系数与桩长的数学表达式,并将Geedes竖向附加应力影响范围与Randolph提出的影响半径对比分析后,给出了桩基影响区域和非影响区域的界定半径;基于支护压力、注浆压力的理论取值范围及单位长度上土体损失量等于沉降槽面积的条件,利用三维弹塑性有限元进行计算分析,给出了支护压力、注浆压力在桩基非影响区域内的建议取值和土体损失的计算表达式;基于桩基非影响区域内盾构施工参数的建议取值及桩基对地层产生的附加应力,给出了桩基影响区域内盾构施工参数建议取值的数学表达式。研究结果表明:工作面的土压力阻力选取工作面静止土压力合力,注浆压力选取1.1倍的隧道埋深处水土压力时,对地层的扰动较小。
[Abstract]:The construction of shield tunnel adjacent bridge pile foundation has become a hot issue. In view of the application value of shield construction parameters in engineering, the vertical additional stress caused by pile foundation is analyzed by using three-dimensional elastic-plastic finite element method, and the pile tip resistance in Geedes formula is deduced. The mathematical expression of the proportion coefficient and pile length of pile top load shared by pile side resistance is given. After comparing the influence range of Geedes vertical additional stress with the influence radius proposed by Randolph, the defining radius of influence area and non-influence area of pile foundation is given. Based on the theoretical range of support pressure, grouting pressure and the condition that soil loss is equal to settlement slot area in unit length, the support pressure is calculated and analyzed by using three-dimensional elastic-plastic finite element method. The proposed value of grouting pressure in the unaffected area of pile foundation and the calculation expression of soil loss, based on the recommended values of shield construction parameters and the additional stress generated by pile foundation on the ground, The mathematical expression of the suggested value of shield construction parameters in the zone affected by pile foundation is given. The results show that the earth pressure resistance of the working face is determined by the combination of static earth pressure in the working face, and when the grouting pressure is 1.1 times the soil and water pressure at the buried depth of the tunnel, the disturbance to the formation is relatively small.
【作者单位】：北京交通大学土木建筑工程学院;中国土木工程集团有限公司;中国新兴保信建设总公司;北京城建设计发展集团有限公司;
【分类号】：U455.43

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