土坝坝坡抗滑稳定分项系数方法：理论和标定

基于可靠度理论的设计方法可在一定程度上考虑计算参数的变异特性和不确定性，在此基础上建立的以概率极限状态为基础的分项系数法可在实际工程中提供简便、有效的设计方法。本文在现行规范的基础上，结合可靠度分析方法和历史经验模型的检验，对土石坝坝坡抗滑稳定分项系数设计方法的原理和分项系数的取值进行了较为全面的阐述。结果表明：土石坝筑坝材料的黏聚力和摩擦系数的分项系数γc和γf宜分别取1.20和1.10。结构安全级别为Ⅰ级（1级土石坝）、Ⅱ级（2、3级土石坝）和Ⅲ级（4、5级土石坝）建筑物的结构重要性系数γ0分别取1.10、1.05和1.0；鉴于特高坝的特殊性，特高坝结构系数γd取1.30 ~ 1.35。结合我国已建的15座土石坝，验证了上述安全控制指标的合理性，本研究成果可为规范的修订和完善提供参考。

Partial factor method for rockfill dam slope stability. Theory and calibration

The design methods based on reliability analysis can consider variations and uncertainties in input parameters to certain extent, while a partial factor method based on probability limit state provides a simple and effective approach in engineering practice. Based on reliability analysis and verification using a historical empirical model, the principle of the partial factor method and its coefficient calibration are investigated comprehensively in this paper. Results show the partial factors of cohesion γc and friction coefficient γf for dam materials should be 1.20 and 1.10 respectively. We suggest that the structural importance coefficient γ0 of grades I (grade 1 rockfill dams), II (grades 2 and 3 rockfill dams) and III (grades 4 and 5 rockfill dams) structures be 1.10, 1.05 and 1.00 respectively. And for super high dams, the structural coefficient γd be 1.30-1.35. These safety control indexes are verified through comparison with those of 15 rockfill dams built in China, thus helping revise the new design code.