地震作用下锚固岩体动力响应机制研究

By taking a typical prestressed anchor system during earthquake as the research object, the chief aim of this study is to reveal the response mechanism of the prestressed anchor system under the seismic load. On the base of the research, the stability analysis method of bolted rockmass considering the damage of prestressed anchor system during earthquake will be established.. During the research, we will study systematically the prestressed anchor system data of practical engineering collected widely, including design data, construction data, and the monitoring data during the construction and operation. The prestressed anchor system dynamic response characteristics of prestress loss and failure during the earthquake will be summarized. According to the summarized prestressed anchor response, we will carry out the physical model test of prestressed bolted rockmass during the whole earthquake; at the same time, the numerical simulation will be carried out. Compared the physical model test result and the numerical simulation result, we can obtain the response character of the prestressed bolted rockmass under the seismic load. Combined the theory analysis, the stability calculation method of bolted rockmass considering the damage of prestressed system under seismic load will be established. The research results will be perfected and supplemented through the application in the practical project.. Innovative points of this research as following: firstly, the physical model test of the prestressed bolted rockmass under the seismic load; secondly, the dynamic response of the prestressed bolted rockmass during the whole process of earthquake; thirdly, the stability calculation method of prestressed bolted rockmass considering the damage of prestressed system under seismic load. The research results of our work have an important significance to the charge mechanism of the prestressed bolted rockmass engineering characteristics and reasonable evaluation of the stability and safe of geotechnical engineering under the seismic load. So, this study has the very important theoretical calue and engineering value.

本课题以地震荷载作用下的锚固岩体为对象展开研究工作，通过系统整理分析实际工程中地震作用后的预应力锚索的运行资料，总结地震作用下锚索的预应力损失与破坏特征；利用大型模型试验，对预应力锚固岩体在地震荷载下的全过程相应进行试验，并开展相应的数值模拟分析，结合理论研究，揭示地震荷载作用下预应力锚固岩体的响应规律，开展能够体现预应力锚固体系在地震荷载作用下震损机制的锚固岩体稳定分析方法研究。本项目创新点包括：预应力锚固岩体在地震荷载下的模型试验方法；地震荷载作用下的预应力锚固岩体的全过程响应规律；以及预应力锚固体系在地震作用下工程特征变化机理以及合理评价地震荷载作用下锚固岩体稳定性具有重要的实际意义，因此，本项目研究具有重要的理论与工程应用。

预应力锚固结构具有较好的变形协调作用，因此在2008 年汶川地震中，预应力锚固结构对工程抗震性能体现出了较好的优越性。但是在地震作用条件下，预应力锚索响应规律等方面机理、规律以及相关评价方法还不成熟。因此，在这样的背景下，该项目主要开展地震作用下预应力锚固体系动力响应规律研究。.通过三年的深入研究，本项目在地震作用下预应力锚索破坏资料收集与分析、地震作用下预应力锚索破坏资料收集与分析、地震作用下预应力锚索破坏资料收集与分析、新型抗震预应力锚索的研制与开发、地震作用下预应力锚索响应的离心机振动台模型设计以及预应力锚固边坡地震作用下稳定评价标准及稳定分析方法等方面开展了深入分析，取得的主要研究成果有以下几个方面：.（1）归纳总结了预应力锚索的主要震损破坏模式。.（2）地震作用下预应力锚索响应规律。通过多种手段，获得了地震作用下预应力锚索响应规律，主要包括：预应力锚索地震荷载作用下响应机理、锚索受力变形变化规律、边坡地震加速度放大系数规律、锚索预应力对地震荷载作用响应的影响、对地震荷载作用的滞后性以及预应力锚索与岩体相互作用等方面；.（3）开展了预应力锚索地震响应分析的离心机模型试验。研究成果包括边坡不同方向地震加速度的放大系数规律、预应力锚索在不同地震荷载条件下的响应规律、地震作用条件下预应力锚索的锚固机理分析三个方面；.（4）提出了一种适用于地震荷载作用的应力削峰式锚索新型结构；.（5）提出一种岩质边坡地震荷载作用下的计算分析方法及相关边坡稳定标准确定方法。.本项目取得的研究成果，是基于多种手段开展的深入研究得到的，并且在项目研究过程中得到的相关研究成果能够为今后利用离心机振动台开展相似的预应力锚索相关模型试验提供重要的参考与借鉴，具有重要的应用前景。该项目研究成果进一步深入挖掘，以及在此基础上进一步开展深入研究，将会取得重要的研究成果。