基于软硬相间滑床岩体结构劣化的抗滑桩嵌固机理研究

The embedded mechanism of anti-slide pile embedded depth is always considered as one of the frontier subjects and difficult problems in the field of landslide protection. As a result, it is necessary to conduct the embedded mechanism study on anti-slide piles in alternating hard and soft layered strata. Due to the dividing effect caused by the bedding planes and joints in the wide range of sedimentary rock, the distinct rock structure will induce the deterioration of deformation and strength parameters. The planned portable lateral bearing plate and three-dimentional dinstinct numerical modeling tests are utilized to reveal the mechanism of rock deformation and strength caused by deterioration and their quantization characterization of hard and weak alternated bedrock. On the basis of the developed physical modeling experimental device for embedded mechanism, the physical and numerical modeling parallel tests with different preferred structural planes, embedded depth, unit layer thickness and dip angle can be conducted. Though the tests results, the mechanical of anti-slide piles can be revealed, and the corresponding mathematical and mechanical computational model of anti-slide embedded depth considering the deformation of parameters can be created. Rock rheological tests could be carried out by surcharge loads, from which the embedded mechanism and long-term safety of anti-slide pile based on deterioration of rock deformation and strength can be studied. The results presented above would be validated by the field tests in Zigui County by Three Gorges Research Center for geo-hazard, Ministry of Education. Furthermore, the determination of anti-slide pile embedded depth based on deterioration of rock deformation and strength and rock rheology can be put forward. The theory and test results from this study can provide significant scientific theory basis for the anti-slide piles projects in alternating hard and soft layered strata.

抗滑桩嵌固机理研究一直是滑坡防治领域重要前沿和难点课题，在滑坡频发的软硬相间地层中尤显突出,亟需开展软硬相间地层中抗滑桩嵌固机理研究。滑床中层面和节理面切割会导致岩体完整性降低，岩体结构劣化将会导致其变形和强度参数劣化；开展滑床岩体离散元数值试验，研制便携式承压板仪进行现场测试，揭示软硬相间滑床变形和强度参数劣化机理及其量化表征；采用自行研制的物理模型试验装置开展不同优势结构面组合、嵌固深度、软硬层厚度和滑床倾角条件下抗滑桩物理模型和数值模拟平行对比试验，揭示软硬相间滑床中抗滑桩嵌固机理，建立考虑岩体参数劣化的抗滑桩嵌固深度数学模型；结合岩体流变试验，研究基于滑床岩体变形与强度参数劣化和岩体流变的抗滑桩嵌固机理机理，依托三峡库区地质灾害野外大型试验场滑坡－抗滑桩原型试验进行对比验证，提出基于滑床岩体参数劣化和岩体流变的抗滑桩嵌固深度确定方法，为广大软硬相间地层分布区抗滑桩工程提供理论依据。

在软硬相间地层中滑坡频发，滑床中层面和节理面切割会导致岩体完整性降低，岩体结构劣化将会导致其变形和强度参数劣化，同时抗滑桩作为一种应用广泛的抗滑结构，因此开展基于软硬相间滑床岩体结构劣化的抗滑桩嵌固机理研究有重要的意义。本项目系统调查了三峡库区秭归县侏罗系软硬相间岩层结构面发育情况，自主研制了水平承压板仪器，提出了滑床变形和强度参数劣化的量化表征方法。基于野外结构面调查与统计、结构面网络模拟技术和分形方法研究了风化劣化和结构面劣化对岩体强度的影响，建立了岩体强度劣化公式。在自主研发的抗滑桩-滑坡物理模型试验装置系统的基础上，运用物理模型试验和数值试验详细研究了抗滑桩在含正交节理上硬下软滑床中抗滑桩的嵌固机理，验证了物理模型试验和数值试验的合理性。开展了多工况正交对比试验，详细研究了正交节理对抗滑桩嵌固机理的影响，提出了基于滑床岩体变形与强度参数劣化的抗滑桩嵌固深度确定方法。依托该项目撰写了《三峡库区侏罗系地层滑坡中抗滑桩布设和结构优化研究》专著，发表中文核心及以上论文18篇，其中SCI论文14篇（包括第一作者7篇、通讯作者7篇）；申请国家发明专利6项，其中授权1项；培养硕士研究生10名；国内外学术会议作报告17次，其中国际高水平专业学术会议6次（包括2次特邀报告和3次邀请报告）。各项指标均圆满完成了预期目标。该项目完成的研究成果为侏罗系软硬相间地层区滑坡防治工程实践提供科学理论基础，具有重要的理论意义和应用价值。