隧道工程大变形研究现状、问题与对策及新型支护体系应用介绍

State of the art:challenge and methods on large deformation in tunnel engineering and introduction of a new type supporting system

从大变形的定义、类型及分级、发生机制及原因、判定标准、工程对策等方面,对国内外隧道工程修建过程中面临的大变形问题进行系统的总结探讨;阐述地下工程开挖过程中平衡转换的力学机制及支护理念,提出预防控制大变形灾害的关键技术与重点突破方向;借鉴超高层建筑中常用的框架核心筒结构设计理念,秉持"先让再抗后刚"大变形控制思想,自主研发软弱破碎地质条件下钢格栅混凝土核心筒支护结构体系,阐述新型支护体系调动围岩主体承载的催化机制和结构自身多级转化辅助承载的变形受力特点;现场试验表明新型支护体系对治理高应力软弱破碎围岩大变形灾害是有效的,为同类地质条件下大变形灾害的预防与治理提供借鉴。

The large deformation disasters occurred during the construction of tunnels were discussed and summarized systematically from the perspectives of the definition,the type,the classification,the fundamental mechanisms,the standard of determination and the measure of control of the large deformation. The mechanical mechanism and the supporting philosophy of equilibrium transfer were illustrated. The key techniques and the important breakthrough were presented. The design method of structural frame core used in the super high-rise building was adopted to form a deformation control strategy of＂release initially,resist then and become rigid at last＂. A new style supporting system of the steel grids with concrete tube core were thus developed to be used in the weak and fractured stratum. The catalytic mechanism of bearing capacity of surrounding rock was explained. The characteristics of the multilevel transformation and load bearing were summarized. The results of field test verified the reliability of the support system.