工程选址的“安全岛”多级逼近与优选理论

THE "SAFETY ISLAND" THEORY BY MULTI-SCALE APPROACHING AND OPTIMUM SEEKING IN ENGINEERING SITE SELECTION

在回顾重大工程区域地壳稳定性研究历史,分析其面临的挑战的基础上,经过论证活动构造区的特点及强震区大坝建筑的经验,结合当前工程建设要求和全球活动构造学研究现状,作者初步建立了重大工程选址的“安全岛”多级逼近与优选理论体系和工作步骤,讨论了其自然哲学和板块构造学基础,进一步发展了由李四光(1965,1967)提出,胡海涛(1979,1984,1988)坚持并发展起来的“安全岛”理论。多级逼近与优选的大意是,根据边界断裂的规模、活动方式或强度与地块内部性状的基本一致性,从大到小逐级确定出一系列地块,并在每级的若干地块中优选出相对稳定者即“安全岛”。提出了用稳定度(Δf)概念描述“安全岛”的稳定程度,并用模式识别方式进行量化表达。为反映“安全岛”的地质地震历史状态,提出据安全期概念建立“安全岛”的工程分类,即分为永久稳定的、相对稳定的和暂时稳定的三类。

Through looking back the history of the study on regional crust stability, and analysing the present situation and the challenge being faced in engineering area, according to the characteristics of active tectonic areas and experiences on the construction of earth or rock - fill dams in strong earthquake regions, the authors have established 'Safety Island' theory system of Multil-scale approaching and optimum seeking and its working process. The hases of the theory are discussed in the plate tectonics and physical philosophy. This is a great development to 'safety Island' thought that Li Siguang proposed in 1965 and 1967, and Hu Haitao has been persisting in and studying since 1979. 'Safety Island' theory of Multi -scale opprouching and optimum seeking consists of several aspects. First) based on the scale, the acting pattern or strength of boundary fault systems and the similarity of the inner properties and the active state in land masses, a series of land masses are determined from large to small size. Second, one or several rather stable land masses can be selected out in every scale land masses. Third, a stability criterion of 'Safety Island' is expressed quantitatively by a concept called stable level ( f) calculated on the pattern recognition theory. Fourth, the authors divide 'Safety Island' into three types in the concept of safety period based on the state ot geological bodies and large earthquake recurrence intervals, which are permanently, relatively, and temporarily stable 'Island'.