桩锚体系治理滑坡与预应力锚索的工程性状研究

发布时间：2018-06-14 22:29

本文选题：桩锚体 + 预应力锚索抗滑桩　；参考：《湖南科技大学》2015年硕士论文

【摘要】：预应力锚索抗滑桩是一种广泛应用于边坡支护体系的支挡结构,是抗滑支挡结构的优化组合,具有提供的锚固力大,结构可靠、安全的特点,但其设计理论及锚索的工程性状分析尚不完善,本文结合已有预应力锚索受力机理研究成果,依托郴州某滑坡治理分析预应力锚索及桩锚体的工程应用以及工程性质。运用理论分析和有限元验证相结合的方法研究预应力锚索抗滑桩在滑坡推力下的变形特性,以及锚索受力情况,借助于ANSYS软件对工程实际施工过程中,边坡岩土体的变形和锚索抗滑桩进行内力计算。本文首先对滑坡推力及地基反力在抗滑桩桩体上的分布情况进行理论分析,根据相关规范,介绍对应的计算方法;分析现有锚索抗滑桩力学模型的现状并指出其中存在的问题,分析锚索抗滑桩的结构受力和预应力锚索抗滑桩的主要参数确定方法,介绍锚索抗滑桩设计包括的设计内容,并分析其不同情况下的计算方法。然后通过对郴州某滑坡的工程治理,对锚索抗滑桩的设计原则、设计步骤及设计方法进行特例分析,对施工过程进行动态监测,根据监测结果分析滑坡的原因以及发展过程,得到了滑坡的形成以及之后的加剧下滑过程,不仅仅有当地复杂的地质原因,还有施工过程中人为的因素对边坡造成不利影响。比如施工过程中,没有考虑开挖施工对滑坡体的破坏,使用不恰当的开挖方式,坡脚开挖后未及时支护,抗滑桩施工时挖桩密度过大,滑坡体自身稳定性破坏过大,未及时控制住变形,不仅没有起到支护作用,而且使滑坡体稳定性更低,加剧了滑坡。因此,在治理滑坡时,治理过程稳定性对滑坡治理的成功与否起着重要的作用,通过比较不同的施工方式对滑坡产生的治理效果差异,确定施工过程中施工方式的重要性。根据设计规范和勘察报告,结合滑坡类型、变形特征、危害对象及稳定性分析,确定对其采用“抗滑桩+锚索+截排水+降水井+注浆+裂缝填埋+辅助措施”相结合的综合工程治理方案。施工锚索抗滑桩时,注意施工方法,设计采用3序施工法施工抗滑桩,跳挖法和边开挖边支护结合起来,尽量减少开挖抗滑桩时对坡体稳定性的破坏。分析动态监测结果,确定滑坡治理时滑坡的滑动趋势,及时做出调整,确保施工过程中边坡的稳定性及施工质量。最后使用ANSYS软件分析滑坡开挖未支护的受力应变趋势,再次分析使用锚索抗滑桩以及普通抗滑桩的支护效果,计算抗滑桩及锚索在支护体系中的受力和应变情况,并和监测结果进行对比,得出ANSYS分析结果和监测结果基本吻合,使用ANSYS软件能够方便、直观的表现出滑坡体及抗滑桩应变性能。
[Abstract]:Pre-stressed anchor cable anti-slide pile is a kind of retaining structure widely used in slope support system. It is an optimized combination of anti-slide retaining structure, which has the characteristics of large anchoring force, reliable structure and safety. However, the design theory and the analysis of the engineering character of the anchor cable are not perfect. In this paper, the engineering application and the engineering properties of the prestressed anchor cable and the pile anchor body are analyzed based on the existing research results of the stress mechanism of the prestressed anchor cable and the pile anchor body based on the treatment of a landslide in Chenzhou. The deformation characteristics of prestressed anchor cable anti-slide pile under the thrust of landslide and the stress of anchor cable are studied by using the method of theoretical analysis and finite element verification, and the actual construction process of the project is carried out by means of ANSYS software. The deformation of slope and soil mass and the internal force of anchor cable anti-slide pile are calculated. In this paper, the distribution of landslide thrust force and foundation reaction force on anti-slide pile body is analyzed theoretically, the corresponding calculation method is introduced according to relevant codes, the present situation of the existing mechanical model of anchor cable anti-slide pile is analyzed and the existing problems are pointed out. This paper analyzes the structural force of anchor cable anti-slide pile and the main parameter determination method of prestressed anchor cable anti-slide pile, introduces the design contents of anchor cable anti-slide pile, and analyzes the calculation methods under different conditions. Then through the engineering treatment of a landslide in Chenzhou, the design principles, design steps and design methods of anchor cable anti-slide pile are analyzed, and the dynamic monitoring of construction process is carried out. According to the monitoring results, the causes and development process of landslide are analyzed. The formation of the landslide and the subsequent process of increasing the slide are not only caused by the local complex geological reasons but also by the man-made factors in the construction process which have a negative impact on the slope. For example, in the construction process, the failure of excavation to the landslide body is not considered, the improper excavation method is used, the slope foot is not supported in time after excavation, the density of the excavated pile is too large during the construction of the anti-slide pile, and the stability of the landslide body itself is destroyed too much. Failure to control the deformation in time not only does not play a supporting role, but also makes the landslide less stable and intensifies the landslide. Therefore, the stability of the control process plays an important role in the landslide control. The importance of the construction mode in the construction process is determined by comparing the different construction methods to the landslide treatment effects. According to the design code and survey report, combined with landslide type, deformation characteristics, hazard object and stability analysis, It is determined that the comprehensive engineering treatment scheme should be adopted in combination with "auxiliary measures of grouting fracture landfill for anti-slide pile Anchorage cable intercepting drainage dewatering well". In the construction of anti-slide pile with anchor cable, attention should be paid to the construction method, and the three-sequence construction method should be used to construct the anti-slide pile. The method of jumping and digging is combined with the side excavation to reduce the damage to the stability of the slope body during the excavation of the anti-slide pile as far as possible. The dynamic monitoring results are analyzed to determine the sliding trend of the landslide and to make timely adjustments to ensure the stability and construction quality of the slope during the construction process. Finally, the stress and strain trend of unsupported landslide excavation is analyzed by ANSYS software, and the support effect of anti-slide pile with anchor cable and common anti-slide pile is analyzed again, and the stress and strain of anti-slide pile and anchor cable in support system are calculated. And compared with the monitoring results, the results of ANSYS analysis and monitoring results are basically consistent, the use of ANSYS software can be convenient, intuitive performance of landslide and anti-slide pile strain performance.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.22;TU473.1

【参考文献】