【作者】 吴翔天；

【导师】 谷拴成；

【作者基本信息】 西安科技大学 ， 岩土工程， 2013， 博士

【摘要】 本文在国内外现有研究成果的基础上，对隧道开挖与施工对既有建筑物桩基影响进行了深入研究，探讨隧道开挖作用下轴向受荷桩的荷载传递规律和桩土相互作用机理，主要进行以下几个方面的工作：（1）建立等效地层损失模型，根据地层变形模式和地层损失的边界条件，应用水平分布荷载作用下的Mindlin基本解，求解隧道开挖引起的地层变形的水平方向和竖直方向表达式；采用三维有限差分方法，建立隧道开挖分析模型，分析隧道开挖引起的土体水平位移和竖向位移分布规律。（2）引用p-y曲线法，通过差分方法求得竖向受荷单桩的解析解；基于Winkler地基模型，建立单桩在被动位移下的荷载传递方程，进一步求得均质地基和非均质地基中隧道开挖引起的竖向受荷单桩水平位移和竖向位移解析解；同时进行算例分析，得到均质地基中隧道开挖引起的桩身位移、沉降和轴力的变化趋势。（3）根据剪切位移法和Mindlin解得到土体竖向和水平向位移传递系数，考虑桩基对土体竖向位移的屏蔽，利用土体剪切位移法计算由于群桩遮拦效应而产生的遮拦位移；考虑被动群桩的桩–桩相互作用，应用叠加原理分析竖向受荷群桩由于隧道开挖引起的竖向位移和内力的变化规律。（4）设计模拟隧道开挖对竖向受荷桩作用的室内试验，将隧道开挖过程简化为施加土体水平位移和竖向位移，按照隧道不同埋深引起的土体位移变化不同，设计不同土体位移组合的竖向受荷单桩和两桩的试验，研究隧道开挖引起的竖向受荷单桩和群桩的承载性状。（5）对某工程实例隧道穿越建筑桩基采取桩基托换措施，采用三维有限差分方法，对隧道开挖及桩基托换施工过程进行模拟，研究托换过程中群桩的承载性状。本文通过数值分析，研究隧道开挖引起的土体位移场分布；通过理论分析，求解隧道开挖作用下的土体位移解析解，并进一步求得隧道开挖作用下竖向受荷单桩及群桩的解析解，研究隧道开挖对竖向受荷单桩及群桩的承载性状的影响；通过试验研究进一步探讨了隧道开挖对单桩和群桩承载性状的影响。更多还原

【Abstract】 Based on the existing research results, the influence of tunnelling on pile foundation inexisting buildings is studied. The load transfer mechanism of axially loaded pile and theinteraction of soil and pile are discussed.This paper research content mainly includes several aspects:（1）The equivalent formation damage model is established, based on the stratumdeformation model and boundary conditions of formation damage, the level distribution loadsof Mindlin fundamental solutions is adopted, the horizontal and vertical expressions of soildisplacement due to tunnelling are solved. Using the three-dimensional finite differencemethod, the analysis model of tunneling is established to analyze the soil horizontal andvertiacal distribution.（2）Adopting p-y curve method, the analytical solutions of single axially loaded pile areobtained by the difference method; Based on the Winkler foundation model, the load transferequation of the single pile subjected to passive displacement is established, the analyticalsolutions of horizontal displacement and vertical displacement of the single pile caused bytunnelling in homogeneous and heterogeneous foundation are worked out. By the analysis ofthe example, the horizontal displacement, vertical displacement and the axial force of thepile due to tunnelling in homogeneous foundation are obtained.（3） According to the shear displacement method and the Mindlin solution for verticaland horizontal displacement of soil transfer coefficient, considering the shielding of soilvertical displacement of pile foundation, the shielding displacement due to pile foundationshielding effect is calculated. Considering the pile-pile interaction of the passive pile groups,the super position principles are used to calculate vertical displacement and internal force ofpile groups caused by tunneling.（4）Design a kind of test apparatus which can simplify working condition of tunnellingto exert the soil lateral displacement and vertical displacement and then carry out indoor test to research the characteristics of single axial loaded pile and pile groups caused by tunnelling.Based on the different soil displacements due to different tunnel depth, different test groupsare designed. The bearing characteristics of single pile and pile groups are obtained.（5） The pile foundation underpinning is taken with tunnelling, the three-dimensionalfinite difference method is used to simulate the process of tunneling and pile foundationunderpinning construction, the bearing capacity of pile groups in the process of pilefoundation underpinning is obtained.Through numerical analysis, the soil displacement distribution caused by tunnelling isstudied. Through theoretical analysis, the analytic solution of the displacement of soil due totunnelling is solved, and the analytical solution of pile and pile groups due to tunnelling isworked out. The influence of tunnelling on single axially loaded pile and pile groups is futherdiscussed. By the model test, the behavior of axially loaded pile and pile grous subjected totunnelling is further studied.更多还原