坝基岩体开挖松弛效应分析与锚固效果评估研究

 针对坝基岩体开挖松弛这类特殊岩石力学问题，系统分析研究松弛判据及参数取值、松弛效应的有限元算法等关键技术问题，基于锚固室内试验和现场试验，推导坝基锚固措施对抗剪安全度效应的经验公式，建立一套简明实用的岩体开挖松弛和锚固分析评估有限元算法。以小湾拱坝为背景，得到坝基岩体松弛的时空特征，对比分析2种锚固方案下小湾拱坝的应力和位移、坝基浅部特征截面特征点安全度和锚杆应力等。计算得到应力–应变场结果与现场监测成果符合较好，说明该研究成果的可靠性和实用性，该研究成果已为设计决策提供依据。

RESEARCH ANALYSIS OF EXCAVATION-INDUCED RELAXATION OF ROCK FOUNDATION AND EVALUATION OF ANCHOR EFFECT

Aiming at specific rock mechanical problem which is about excavation-induced relaxation of rock foundation，key technologies such as criterion and calculating method of relaxation，finite element algorithm of relaxation effect are deeply studied. Based on laboratory and in-situ rock mechanical experiments，an experiential formula of the shear safety factor effect is provided when rock is anchored. A practical finite element algorithm for the evaluation of relaxation and anchor effect is established. Taking Xiaowan arch dam as background，spatial-time distribution of foundation rock mass relaxation is displayed；two anchoring cases are compared on the basis of stress，deformation，the shear safety factor of critical section in shallow dam foundation and bolt stress. The reliability and practicality of this research is verified by the comparative analysis between numerical simulation and monitoring data. This research has provided a reliable basis for the decision-making.