海底隧道最小岩石覆盖厚度的位移收敛法  

Displacement convergence method for minimum rock cover above submarine tunnel

作　　者：李树忱[1] 张京伟[2] 李术才[1] 徐帮树[1] 

机构地区：[1]山东大学土建与水利学院地下系,济南250061 [2]山东省建筑设计研究院,济南250001

出　　处：《岩土力学》2007年第7期1443-1447,共5页Rock and Soil Mechanics

基　　金：国家自然科学基金重点项目(No.50539080);山东省自然科学基金面上项目(No.Y2006F13)

摘　　要：关于岩体稳定评判准则至今尚未达到成熟的阶段,从稳定的定义、量化的判断到分析的理论、准则和方法等一系列基本问题尚未形成明确的系统。目前比较常用的方法就是利用塑性区来判断围岩的稳定范围。但塑性区主要用来确定围岩的破坏范围,对于确定海底隧道的最小覆盖层厚度有些过于危险,因为一般海底隧道主要修建于硬岩中,其开挖引起的塑性区很小。因此,有必要建立确定海底隧道最小岩石覆盖厚的方法。应用适合模拟岩土大变形的数值分析方法FLAC3D,运用围岩变形量或变形率判据,建立确定海底隧道最小岩石覆盖厚度的位移收敛判据,并将该判据用于确定某海底隧道的最小岩石覆盖厚度,以说明该方法用于确定海底隧道最小岩石覆盖厚度的正确性和有效性。So far there has been no a ripen criterion to judge the stability of a rockmass that can be accepted unanimously. That is, no a clear system has not been formed yet that covers a series of basic problems, such as definition and quantitative judgment of stability or theory and method and criterion to analyze rockmass stability. At present, the commonly used method it to judge the stability of rocks surrounding a project according to plastic zones. However, this method is just used mainly for determining the failure scope of surrounding rocks. It is too dangerous if the method is used to determine the minimum rock cover thickness above a submarine tunnel, because ordinary submarine tunnels are mostly excavated in hard rocks, producing small plastic zones. Therefore, it is necessary to establish a method to determine the minimum rock cover thickness of a submarine tunnel. The mumerical analysis method FLAC3D applicable to simulalating large deformations of rocks and soils is adopted in this paper to establish a criterion according to the deformation or deformation rate criterion of surrounding rocks that be used for determining the minimum rock cover thickness of a submarine tunnel. This criterion has been successfully used in Xiangshan harbor＇s submarine tunnel, and the estimated minimum rock cover thickness is coincident with that from traditional engineering analogy method, which shows the rightness and avidity of the method proposed in the paper.

关 键 词：海底隧道 位移收敛法 最小岩石覆盖厚度 FLAC3D 

分 类 号：O241[理学—计算数学]