不同应力场软弱围岩公路连拱隧道力学特征试验  

Model tests for soft-weak surrounding rocks highway multiple-arch tunnel stress characteristics in different stress fields

作　　者：来弘鹏[1] 谢永利[1] 杨晓华[1] 

机构地区：[1]长安大学公路学院,陕西西安710064

出　　处：《长安大学学报（自然科学版）》2008年第6期60-64,共5页Journal of Chang’an University(Natural Science Edition)

基　　金：国家西部交通建设科技项目(200131800021)

摘　　要：为了更全面了解不同应力场软弱围岩公路连拱隧道的力学特征,选择曲中墙连拱隧道结构形式,基于'先加载后开洞'思路,开展施工过程相似模拟试验,研究不同应力场软弱围岩连拱隧道施工应力变化特征,分析应力场对支护结构受力的影响。试验结果表明:不同应力场,在左、右洞开挖过程中,侧压力系数较小时,拱底和拱顶应力释放最为显著,侧压力系数较大时,拱腰应力释放最为显著;围岩与衬砌接触压力,除在中墙顶、底方向随侧压力系数的增大而略有减小外,其他各方向均随侧压力系数的增大而增大;中墙压应力的量值随侧压力系数的减小而增大;左、右洞衬砌结构内外侧受力不对称,且侧压力系数对衬砌结构的切向应力影响很大,即随着侧压力系数的增大,切向应力最大值位置逐渐由外侧拱腰向拱顶过渡。In order to more fully grasp the construction stress characteristics of surrounding rock of highway multiple-arch tunnel under different stress fields, a lot of multiple-arch tunnel model tests are carried out by the test flat and excavation apparatus, which pay more attention to the stress change of multiple arch tunnel lining due to excavation and the effect of stress field. The result of model tests shows that： for different stress fields, on the left and right tunnel excavation process, when the lateral pressure coefficient is smaller, the release of arch bottom and vault is the most significant,when the lateral pressure coefficient is relatively large, the release of hance is the most notable; as the rock contact pressure, the contact pressure is slightly decreased with the lateral pressure coefficient＇s increasing at the top and bottom of middle wall direction, all the other directions＇ increase with the increasing of lateral pressure coefficient, and the influence is also quite noticeable; the compression stress value of middle wall pressure in the whole construction process is greater with the lateral pressure coefficient being smaller; the lateral loadings of right and left holes lining structure are not symmetry, and lateral pressure coefficient has a great impact on the tangential stress of lining, with the increasing of lateral pressure coefficient, the maximum position of tangential stress will evolve from hance transition to vault one. 1 tab, 6 figs, 8 refs.

关 键 词：隧道工程 软弱围岩 连拱隧道 应力场 力学特征 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]