摘要
基于流固耦合理论,推导海底隧道圆形衬砌结构水压力计算公式。以汕头湾海底隧道为工程依托,结合有限差分软件FLAC 3D建立全包与半包隧道模型,分析不同海水深度、不同防排水形式下围岩渗流场特征,孔隙水压力、衬砌结构位移和能量变化规律。结果表明:不同海水深度下Ⅱ级围岩段隧道稳定性均明显优于Ⅳ级围岩段,Ⅳ级围岩段全包隧道孔隙水压力均大于半包隧道,Ⅱ级围岩段全包与半包隧道孔隙水压力基本一致;对于隧道衬砌结构位移,同一海水深度下全包、半包隧道相差极小,海水深度小于等于15 m时位移随海水深度增加而稳步小幅增大,海水深度20 m时Ⅱ级围岩段位移剧增,Ⅳ级围岩段增幅较Ⅱ级围岩段小;海水深度小于15 m时,全包、半包隧道的能量差异较小且耗散能略小于弹性应变能,海水深度为15 m(半包隧道)、20 m时耗散能明显大于弹性应变能;隧道围岩塑性区单元数量与海水深度正相关,海水深度从5 m增至10 m、15 m增至20 m时,塑性区单元数量呈跳跃式增长。
Based on the fluid-structure coupling theory,The water pressure calculation formula of the circular lining structure of subsea tunnel was derived.Based on the Shantou Bay subsea tunnel project and combined with the finite difference software FLAC 3D,the models of fully enclosed and half enclosed tunnel ware established to analyze the seepage field characteristics of surrounding rock and the evolution law of pore water pressure,lining structure displacement and energy damage under different seawater depths and different drainage conditions.The results show that,under different sea water depths,the tunnel stability of ClassⅡsurrounding rock section is significantly better than that of ClassⅣsurrounding rock section.The pore water pressure of the fully enclosed tunnel in ClassⅣsurrounding rock section is greater than that of the half enclosed tunnel,and the pore water pressure of the fully enclosed tunnel in ClassⅡsurrounding rock section is basically the same as that of the half enclosed tunnel.For the displacement of the tunnel lining structure,the difference between the fully enclosed and half enclosed tunnels under the same sea water depth is very small.When the sea water depth is less than or equal to 15 m,The displacement increases steadily and slightly with the increase of the sea water depth.When the sea water depth is 20 m,the displacement of the ClassⅡsurrounding rock section increases sharply,and the increase of the ClassⅣsurrounding rock section is smaller than that of the ClassⅡsurrounding rock section.When the sea water depth is less than 15 m,the energy difference between the full enclosed and half enclosed tunnel is small and the dissipated energy is slightly less than the elastic strain energy.When the sea water depth is 15 m(half enclosed tunnel)and 20 m,the dissipated energy is significantly greater than the elastic strain energy.The number of plastic zone elements in the surrounding rock of the tunnel is positively correlated with the depth of sea water.When the depth of sea water increases from 5 m to 10 m,and from 15 m to 20 m,the number of plastic zone elements increases by leaps and bounds.
作者
秦松
陈云娟
盛圣胜
王乐宁
高涛
刘效智
QIN Song;CHEN Yunjuan;SHENG Shengsheng;WANG Lening;GAO Tao;LIU Xiaozhi(The First Engineering Development Co.Ltd.of China Railway 14th Bureau Group,Rizhao Shandong 276800,China;School of Civil Engineering,Shandong Jianzhu University,Jinan 250101,China;Key Laboratory of Building Structural Retrofitting and Underground Space Engineering,Ministry of Education,Shandong Jianzhu University,Jinan 250101,China)
出处
《铁道建筑》
北大核心
2023年第3期103-107,共5页
Railway Engineering
关键词
海底隧道
全包隧道
半包隧道
数值模拟
渗流场
海水深度
孔隙水压力
能量损失
subsea tunnel
full enclosed tunnel
half enclosed tunnel
numerical calculation
seepage field
seawater depth
pore water pressure
energy damage
