三峡库区侏罗系软硬相间地层中抗滑桩嵌固机理试验研究

The determination of anti-slide pile embedded depth is always considered as one of the frontier subjects and difficult problems, especially for the landslides in the Jurassic alternating hard and soft layered strata region. Therefore, it is urgent to carry out the embedded mechanism study of anti-slide piles in Jurassic alternating hard and soft layered strata. Majiagou landslide in the Three Gorges Reservoir Region is presented as the case study in this project. On the basis of the engineering geology and sequence stratigraphy methods, the lithology combined features of Jurassic alternating hard and soft layered strata can be examined to establish the geological-mechanical model of the anti-slide piles and alternating hard and soft layered rock. The physical modeling experimental device for embedded mechanism is planned to be developed. By using the lab similar material physical and numerical modeling parallel tests, the mechanical and deformation tests of anti-slide piles can be conducted by uniform experimental design under different cases. The mechanical characteristic and deformation law of anti-slide pile could be analyzed based on the tests results presented above, from which the embedded mechanism of anti-slide pile in Jurassic alternating hard and soft layered strata can be revealed. The corresponding mathematical and mechanical computational model of anti-slide embedded depth in alternating hard and soft layered strata can be created, which would be validated by the field tests in Zigui County by Three Gorges Research Center for geo-hazard, Ministry of Education. The optimal computational model of anti-slide embedded depth in alternating hard and soft layered strata can be built based on the optimality theory. The theory and test results from this study can provide significant scientific theory basis for the anti-slide piles projects in the Jurassic alternating hard and soft layered strata, with valuable theoretical significance and engineering application.

抗滑桩嵌固深度的确定一直是滑坡防治领域重要的前沿课题和难点问题之一，在滑坡频发的侏罗系软硬相间地层中这一难题尤显突出,亟需开展侏罗系软硬相间地层中抗滑桩嵌固机理研究。以三峡库区秭归县马家沟滑坡为例，采用工程地质和层序地层方法，分析侏罗系软硬相间地层岩性组合特征，建立抗滑桩与侏罗系软硬相间岩层地质力学模型。自行研制抗滑桩嵌固机理物理模型试验装置，基于物理模型和数值模拟平行对比试验，系统开展不同工况条件下抗滑桩受力和变形的均匀设计试验；分析抗滑桩受力特征与变形规律，揭示侏罗系软硬相间地层中抗滑桩嵌固机理，建立抗滑桩嵌固深度数学力学模型。依托教育部长江三峡库区地质灾害研究中心野外试验场原型试验监测与测试进行应用效果验证。采用最优化理论,构建侏罗系软硬相间地层中抗滑桩最优嵌固深度计算模型。本课题理论和试验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。

三峡库区侏罗系地层具有独特的软硬相间的岩性组合和结构特征广泛分布于三峡库区的秭归、兴山、云阳、万州、忠县、开县乃至四川东部等广大地区，同时也是滑坡集中发育的地层之一，是三峡库区滑坡防治工作中的重点区域。抗滑桩作为一种抗滑结构广泛用于滑坡治理工程中，其嵌固机理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,亟需开展软硬相间地层中抗滑桩嵌固机理研究。本课题以三峡库区秭归县马家沟滑坡为例，通过野外现场调查、测试，采用工程地质和层序地层方法，分析侏罗系软硬相间地层岩性组合特征，建立抗滑桩与侏罗系软硬相间岩层地质力学模型。在已研发的抗滑桩-滑坡物理模型装置基础上进一步完善，并系统开展了不同工况条件下抗滑桩受力和变形的均匀设计试验；同时开展了数值模拟平行对比试验分析抗滑桩受力特征与变形规律，揭示侏罗系软硬相间地层中抗滑桩嵌固机理，建立抗滑桩嵌固深度数学力学模型。课题执行期间完成了对三峡库区侏罗系软硬相间地层中抗滑桩嵌固机理的研究，揭示了抗滑桩在软硬互层地层中力学特性与变形特征，采用最优化理论与方法，构建了考虑滑床岩体结构特征的抗滑桩嵌岩深度计算模型，为三峡库区侏罗系软硬地层滑坡治理工程抗滑桩设计计算提供了一定的理论基础。依托该课题完成了《三峡库区侏罗系地层滑坡中抗滑桩布设和结构优化研究》专著的撰写，申请相关专利共了9项，发表文章13篇，其中以第一作者发表文章8篇，均被SCI/EI收录，以第二作者发表文章5篇。培养硕士研究生4名，指导的硕士论文《基于钢筋混凝土复合弹性模量的抗滑桩截面优化研究》获得湖北省优秀硕士学位论文。依托该项目的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。