【作者】 王树丰；

【导师】 殷跃平；

【作者基本信息】 长安大学 ， 地质工程， 2010， 博士

【摘要】 微型桩由于具有施工机具小,适用于狭窄的施工作业区；对土层适应性强,几乎适用于任何土(岩)层；施工振动小,噪音小；对岩土体扰动小,不需要大面积开挖；桩位布置形式灵活,可以布置成斜桩；施工迅速,桩体发挥作用所需时间短等优点,成为地质灾害治理,尤其是应急抢险治理工程的首选。虽然微型桩技术工程应用较多,但由于应用时间较短,人们对其受力变形特性没有足够的了解,其设计计算理论方法缺乏足够的工程例证,缺乏系统的工程治理效果检验实例。本文以滑坡灾害微型桩防治技术大型物理模型试验及凤凰山滑坡微型桩治理工程为基础,通过室内物理模型试验、详细勘察、数值分析及野外工程实践应用等方法和手段,主要在以下几个方面开展了系统的研究：(1)运用槽探、钻探、坑探及物探等勘察方法对凤凰山滑坡进行详细勘察,确定了其潜在滑动面,并对其稳定性进行了计算分析。(2)通过对凤凰山滑坡多种治理方案进行对比分析,确立了最终的滑坡治理方案。(3)通过微型桩防治技术大型物理模型试验,系统研究了微型桩的破坏模式及桩身应力应变规律。根据模型剖面开挖,获知了桩身破坏模式及桩身变位；根据应变计测试结果,总结了桩身内力分布规律,由此绘制了微型桩“P-y”曲线,并拟合出相关公式。(4)通过对凤凰山滑坡微型桩所受土压力进行实时监测,获得了微型桩所受滑坡推力及桩后岩土体抗力的实时变化过程。(5)根据凤凰山滑坡微型桩防治工程地表位移实时监测数据,研究了微型桩防治工程的地表变位情况。(6)通过凤凰山滑坡治理工程微型桩受力特性和地表位移监测结果对比分析,验证了地震滑坡微型桩防治工程的效果。通过上述内容的研究,论文主要取得了以下成果：(1)系统分析了滑坡微型桩变形破坏机理。获得了微型桩推力的分配模式,得出了桩身弯矩及剪力分布曲线,确立了影响桩身弯矩及剪力的范围,并拟合出了微型桩桩身应力与变位关系方程式。(2)获得了抗滑工程实践中微型桩的实时受力变形过程。总结了桩身所受滑坡推力及桩后岩土体抗力的分布特点,结合地表位移监测结果,分析了微型桩加固后滑坡体的稳定性。(3)建立了震裂坡体滑坡微型桩防治工程示范。通过滑坡微型桩防治技术大型物理模型试验及凤凰山滑坡微型桩应用工程实践,认为采用微型桩对滑坡体进行加固后能效提高滑坡的稳定系数。其成功经验可为同类地震滑坡及其他类型滑坡的应急抢险治理提供示范。更多还原

【Abstract】 Micropile has been used in landslide reinforcement more and more popular, especially used in rescuing project because of the merits:little machinery; adaptability to stratum; little vibration and low noise; low influence to the landslide; various layout mode; rapid constructing speed. Although micropile technology put into use in engineering is more popular, its deformation characteristics have not been fully understood, its design calculation theory methods are short of enough engineering examples and systemic engineering inspection because of its short application time.Based on China Geological Survey item "Large scale model text on micropiles in landslide reinforcement" and phoenix landslide prevention engineering for micropile, through the interior of physical model experiment, the detailed investigation, numerical analysis and field engineering practice method and means, the following aspects are systematically studied:(1) Using trough, drilling, pitting and geophysical exploration methods of such detailed investigation, the potential sliding surface of phoenix mountain landslides is confirmed, and its stability is calculated and analyzed.(2) Through various treatment solutions for phoenix landslide, the final solution for management is established.(3) Based on "Large scale model text on micropiles in landslide reinforcement", failure mode and rule for its stress and strain of micropile are detailedly studied. According to the result of excavation, failure mode and strain of micropile are analyzed. Rule for its stress is summarized based on the results, and curves of "P-y" are drew, fitting formulas are provided subsequently.(4) By real-time monitoring for soil pressure, changing processes for micropile referred to thrusting force of pile and soil resistance of the body are acquired.(5) According to results of surface displacement control engineering for phoenix mountain landslide, surface deflection for prevention engineering of micropile is studied. (6) Comparative analyses between the results from monitoring for soil pressure and from surface displacement control engineering are studied, and effectes of prevention engineering of micropile are verified.Through the above content of study, this paper mainly made the following results:(1) Deformation and failure mechanism of micropile are systematically analyzed. Distribution pattern for thrust of micropiles is acquired, bending and shearing curves are drew, fitting formulas for stress and strain are provided.(2) Real-time processes for stress and deformation of micropile in phoenix landslide are got. Stability for phoenix landslide with micropiles is calculated combining with the results from monitoring of surface displacement control engineering.(3) An example for shattering mountain prevention with micropile is established. Through the results from "Large scale model text on micropiles in landslide reinforcement" and phoenix landslide prevention engineering for micropile, successful experience from which landslide with micropile can be more stable will provide an example for other seismic landslides and other type landslides.更多还原