降雨作用下堆积层边坡与下穿隧道相互作用模型试验研究  

Model test on interaction between colluvial slope and underpass tunnel under rainfall

作　　者：张永杰 胡涛 郭一鹏 邓沛宇 罗志敏 陶坡 ZHANG Yong-jie;HU Tao;GUO Yi-peng;DENG Pei-yu;LUO Zhi-min;TAO Po(School of Civil Engineering,Changsha University of Science&Technology,Changsha,Hunan 410114,China;Road&Brdige Southern China Engineering Co.,Ltd.,Zhongshan,Guangdong 528400,China)

机构地区：[1]长沙理工大学土木工程学院,湖南长沙410114 [2]中交路桥华南工程有限公司,广东中山528400

出　　处：《岩土力学》2024年第12期3613-3623,共11页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51878071,No.52178416,No.52478440);土木工程优势特色重点学科创新性项目(No.18ZDXK08)。

摘　　要：为了掌握降雨条件下堆积层边坡蠕动变形规律以及隧道衬砌结构受力变形特征,利用土压力盒、应变片、百分表和湿度计等测试仪器,开展了降雨工况下隧道-边坡平行体系渗流与受力变形特性的响应物理模型试验。试验结果表明,在降雨过程中,雨水的入渗深度跟边坡高度以及与坡面的距离呈反比,隧道的存在会影响雨水的渗流路径,导致隧道上方坡体的雨水入渗速率加快、含水率峰值增大,而隧道下方坡体的雨水入渗速率减缓、含水率峰值减小;坡体变形量与含水率变化速率正相关,坡体变形集中在含水率快速上升阶段,在这个阶段,坡顶、坡中和坡脚发生的竖向位移分别占降雨全过程总竖向位移量的89.6%、96.4%、98.9%;同时隧道随边坡变形而受压,隧道顶部由边坡变形带来的土压力增量同隧道在堆积体中的埋深正相关,平均每隔15 cm增加24%,基岩端土压力增量约为洞口端土压力增量的2.4倍,且隧道底部土压力增量小于隧道顶部土压力增量;隧道受力变形特征表现为顶部受压,底部受拉,隧道整体下沉,局部呈以中心位置为反曲点的向下的弯曲变形,并在基岩-堆积层交界处受剪切应力影响,在交界处外侧的应变发生突变,近似于一端铰接,一端锚固的梁结构受力模式。建议在同类型的隧道设计施工过程中,在隧道上部边坡表面增加喷混凝土、浅层注浆或采用边坡生态防护等防渗措施,对隧道洞口区域以及隧道变形较大的中部及岩土交界位置进行加固处理。In order to master the creep deformation law of colluvial slope and the stress deformation characteristics of tunnel lining structure under rainfall,the response physical model test of seepage and stress deformation characteristics of tunnel slope parallel system is carried out by using earth pressure cells,strain gauges,dial indicators and hygrometers.The test results indicate that rainfall infiltration depth decreases with increasing slope height and distance from the slope surface.The existence of the tunnel will affect the seepage path of rainwater,accelerating infiltration and increasing peak moisture content on the slope above the tunnel,while decelerating infiltration and reducing peak moisture content on the slope below the tunnel.The slope deformation is positively correlated with the change rate of water content.Slope deformation is concentrated during rapid water content increase,with vertical displacements at the slope top,middle,and foot accounting for 89.6%,96.4%,and 98.9%of the total,respectively.The earth pressure increment at the tunnel top due to slope deformation correlates positively with the tunnel’s buried depth in the accumulation body,with an average increase of 24%per 15 cm.The earth pressure increment at the bedrock end is approximately 2.4 times that at the entrance end,while the increment at the tunnel bottom is smaller than that at the top.The tunnel exhibits the following stress and deformation characteristics:compression at the top,tension at the bottom,overall sinking,local downward bending with the central position as the inflection point,and abrupt strain changes at the bedrock-accumulation layer junction due to shear stress.These characteristics resemble the stress mode of a beam structure with one end hinged and one end anchored.It is recommended to incorporate anti-seepage measures such as sprayed concrete,shallow grouting,or slope ecological protection on the upper slope of the tunnel during the design and construction of similar tunnels.Reinforcement treatment should be im

关 键 词：模型试验 人工降雨 隧道 堆积层边坡 

分 类 号：TU42[建筑科学—岩土工程]