高心墙堆石坝坝基廊道受力特性研究

在中国水资源最为丰富的西部地区,河床覆盖层厚达数十米甚至百米,一大批土石坝正在和将在这些大江大河上建设。坝体心墙与坝基防渗墙多采用廊道这种结构型式进行连接,廊道受力条件复杂,是工程成败的关键,但是有些已建工程却出现了廊道漏水的现象,廊道开裂和结构缝破坏成为亟待解决的问题。为了对廊道受力情况和开裂规律有一个清楚的认识,分析总结了几个工程廊道的监测资料,同时基于混凝土非线性本构理论,建立有限元模型对廊道进行了数值模拟。对监测结果和数值计算结果进行对比分析之后,探讨了廊道中的结构缝问题和廊道整体的受力规律,指明了廊道中需要重点关注的易开裂部位,为廊道合理配筋提供了指导,同时为类似工程的决策提供参考。

Stress characteristics of foundation gallery of high core wall rockfill dam

There are deep overburdens, tens to hundreds of meters thick, on riverbeds in western China where many rockfill dams are under construction or will be built. A concrete cut-off wall is always constructed in the overburden beneath high rockfill dam to control the seepage through dam foundation, and a gallery is usually built to connect the cut-off wall with the earth or asphalt concrete core within the dam. Since the foundation gallery is under complicated condition, fracture and leakage are found in the galleries of some rockfill dams in operation, which endangers the safety of dams to a certain extent. In order to study the cracking laws and stress states of the foundation gallery, the monitoring data of several galleries of rockfill dams with earth or asphalt concrete cores are analyzed. One of the galleries is calculated by using the finite element method, and the dam construction and water impounding processes are simulated. The nonlinear elastic model is employed to simulate the concrete gallery. The laws of the stress states and the behaviors of structural joints of the gallery are obtained. The vulnerable parts of the gallery and some improvements of the reinforcement design for the gallery are suggested, which is helpful for similar projects.