堆积体-抗滑桩与堆积体-基岩接触面剪切力学特性对堆积体滑坡推力分布形式的影响研究

The anti-sliding pile is efficient method for treating accumulation landslide. The research on distribution of landslide thrust is not enough and it is difficult to quantify distribution of landslide thrust. In practice, arbitrary assumption on distribution of landslide thrust which has great effect on pile internal force often leads to the failure of anti-sliding pile. On the basis of previous research, We found that distribution of landslide thrust is closely related to shear properties of accumulation body-bedrock interface and accumulation body-anti-slide pile interface . Taking accumulation landslide sliding along the bedrock surface for example, we carry out large-scale direct shear test on the anti-sliding pile-accumulation body interface and on the accumulation body-bedrock interface, so that we can obtain the mechanical properties of the above interface. A new statistical damage constitutive model of the anti-sliding pile-accumulation body interface and the accumulation body-bedrock interface is established on the basis of statistical theory and damage theory. Base on introducing the above constitutive model by catastrophe theory, the formula for calculating distribution of landslide thrust is derived. So coupling relationship between the above constitutive model and distribution of landslide thrust is established. We show how the shear properties of the above interface how to affect the distribution of landslide thrust, and give a elucidation with specific research result. It is of significance for further understanding mechanical properties of accumulation body-bedrock interface and accumulation body-anti-slide pile interface. If the research is achieved, we can provide scientific basis for quantification of distribution of landslide thrust and blind choice of the distribution of landslide thrust will be avoided. In addition, the key theory which support the anti-sliding pile design is provided. So the research is important to guarantee reasonability and security of the anti-sliding pile and promote the development of the scientific theory of nonlinear systems in the field of engineering geology.

滑坡推力分布形式选择的是否合理直接影响抗滑桩桩身内力和变形计算，进而对抗滑桩设计的安全性、合理性和经济性产生重大影响。以基岩面滑动型堆积体滑坡为代表，开展堆积体-抗滑桩、堆积体-基岩大型直剪试验，深入分析堆积体-抗滑桩和堆积体-基岩接触面剪切力学特性并建立其剪应力-剪应变模型；引入非线性系统科学中的突变理论，在对抗滑桩-滑坡模型进行平衡分析基础上获取其失稳力学判据，进而得到考虑上述剪应力-剪应变模型影响的堆积体滑坡推力分布的计算方法，并进行大型原型试验。在此基础上阐明堆积体-抗滑桩和堆积体-基岩接触面剪切力学特性对堆积体滑坡推力分布形式的影响规律。该研究将有利于深化对堆积体-抗滑桩和堆积体-基岩接触面力学特性的认识，为堆积体滑坡推力分布形式的合理确定提供科学依据，对确保抗滑桩安全运营，减少不必要经济投入具有重要现实意义，对促进非线性系统科学在工程地质学领域中的发展运用具有一定的理论价值。

滑坡推力分布形式选择的是否合理直接影响抗滑桩桩身内力和变形计算，进而对抗滑桩设计的安全性、合理性和经济性产生重大影响。以基岩面滑动型堆积体滑坡为代表，开展堆积体-抗滑桩、堆积体-基覆面大型直剪试验，在大型直剪试验成果基础上，发现土石混合体介质与接触面在剪切试验中表现出应变硬化和应变软化两种接触面力学性质，建立了能够描述上述两种接触面力学性质的本构方程。通过引入求系统极值的尖点突变理论推导了堆积体滑坡抗滑桩所受推力的计算公式，并深入分析了主要参数对滑桩所受推力大小及分布特征的影响，揭示堆积体-抗滑桩和堆积体-基覆面剪切力学特性对堆积体滑坡推力分布形式的影响规律，最后将所建立的公式应用到一个堆积层古滑坡实例中，对比分析表明该公式的计算结果与现场实测结果具有较好的一致性。