水工抗震设计规范和可靠性设计

在采用传统的安全系数法或可靠性设计法的问题上,目前在水利和水电部门间存在不同意见。由此给设计人员带来了一定的困惑和不便。本文概述了水工建筑物向可靠度设计方法发展的趋势及其在相当程度上仍依赖工程经验的水工建筑物应用中存在的问题。认为:潘家铮院士提出的"积极慎重,转轨套改"是解决矛盾的指导思想。可采用在以分项系数表征的极限方程中引入能反映非随机性不确定性的结构系数。迄今,在水工结构设计中,对目标可靠度的确定等问题尚有待深入研究,作用和材料性能的分项系数主要根据其自身变异特性,依托专家的工程经验确定。在给定的作用和材料性能的分项系数情况下,由与现行的安全系数套改确定结构系数。简介了经水利部和电力工业部共同颁布的现行《水工建筑物抗震设计规范》在修编中的转轨套改,并期盼这种处理方式能继续为两个部门所保持。

Seismic design code and reliability design of hydraulic structures

There are different points of view between water resources and hydropower sectors concerning the use of traditional safety factor method and??or reliability design method. This situation leads to some confusions and troubles for designers. This paper briefly explains the tendency to using reliability design method and its existing problems for hydraulic structures which is depending on engineering experiences in quite large extent. It seems that the ideal of ?? actively transferring to reliability design formation while cautiously keeping continuous pace with existing safety evaluation??, suggested by Academician PAN Jiazheng, is an affective way to solve the above-mentioned contradictions. One factor, so called ??structure factor ??d ?? , is introduced into the limited state equation in form of part ial factor to reflect all the nonrandom uncertainties in designs. So far for hydraulic structures the partial factors are adopted mainly on the basis of engineering experiences of experts according to their random propert ies rather than strictly derived form. The objective reliability indexes cannot be defined reasonably yet . With all concerned factors reflecting actions and material properties being given, the structure factor can be determined in accordance with the traditional safety factor. The procedure of reliability design based on this ideal of the current?? Specification for Seismic Design of Hydraulic Structures?? issued by the above two sectors is briefly introduced. It is expected that such procedure can still be accepted by both sectors.