TBM穿越中风化花岗岩最小覆岩厚度研究  

Study on Minimum Overburden Thickness of Weathered Granite in TBM Traversing

作　　者：刘邦[1] LIU Bang(Sinohydro Engineering Bureau 8 Co.,Ltd.,Changsha 410004,China)

机构地区：[1]中国水利水电第八工程局有限公司,长沙410004

出　　处：《交通科技》2023年第4期87-92,共6页Transportation Science & Technology

摘　　要：文中基于midas GTS对全断面隧道挖掘机穿越中风化花岗岩的最小覆岩厚度进行研究,通过4个不同地质断面条件和改变覆岩层厚度分析隧道与地表位移特征。结果表明,在隧道与地表横向地层竖向位移特征中,拱顶同高度处横向地层竖向位移表现为覆岩层厚度越大,最大沉降值越小,隧底同高度处横向地层竖向位移与覆岩层无关,横向地表竖向位移表现为覆岩层厚度越大,最大沉降值越小,最大沉降值出现在左、右线隧道中间;在隧道与地表纵向竖向位移特征中,覆岩层上部土层厚度越大,隧道拱顶沉降越大,隧底隆起值越大,地表沉降值越大;覆岩层越厚,隧道拱顶沉降越小,隧底隆起值越大,地表沉降值越小。文中在4个不同地质断面条件下在覆岩层厚度取值为0.055 D、0.11D、0.165D、0.22D(D为隧道外径)时位移特征均满足规范要求,因此TBM穿越中风化花岗岩最小覆岩厚度可取0.055 D。Based on the numerical simulation software midas GTS,the minimum overburden thickness of weathered granite in tunnel boring machine traversing was studied.The characteristics of tunnel and surface displacement were analyzed through four different geological section conditions and changing overburden thickness.The results show the horizontal displacement and vertical displacement characteristics of tunnel and ground.The vertical displacement of the horizontal stratum at the same height of the vault shows that the greater the thickness of the overburden,the smaller the maximum settlement value;the vertical displacement of the tunnel bottom is independent of the overburden;the vertical displacement of the horizontal surface shows that the greater the thickness of the overburden,the smaller the maximum settlement value;the maximum settlement value appears in the middle of the left and right line tunnel.In the characteristics of vertical displacement between tunnel and surface,the larger the thickness of the upper layer of overburden,the larger the settlement of tunnel vault,the larger the uplift value of tunnel bottom,and the larger the settlement value of surface.The thicker the overburden is,the smaller the settlement of tunnel arch,and the larger the uplift value of tunnel bottom and the smaller the settlement value of surface.The displacement characteristics meet the standard requirements when the overburden thickness is 0.055 D,0.11 D,0.165 D and 0.22 D,where D is the outer diameter of the tunnel,under four different geological section conditions.Therefore,the minimum overburden thickness of weathered granite in TBM crossing is 0.055 D.

关 键 词：下穿 中风化岩层 最小覆岩厚度 位移特征 

分 类 号：U456[建筑科学—桥梁与隧道工程]