Study on influence of layered placement and temperature load on heel stress of gravity dam during construction period
[Objective]Dam heel stress is a key control index to evaluate the safety of gravity dams.In the design of gravity dam,the gravity load is applied once,without considering the actual pouring process and temperature load during construction.There-fore,[Methods]based on the dam design data and temperature monitoring data,the key thermal parameters of dam concrete in No.2 spillway section of Three Gorges Gravity Dam Project are inverted.On this basis,simulating the dam construction process,material properties change process,temperature change process,longitudinal joint grouting process,water cooling process and surface insulation measures,the working behavior simulation analysis is carried out during the construction period of the dam,and the influence of layered pouring and temperature load on the dam stress is studied,especially the dam heel stress.[Results]The result show that the temperature variation of the monitoring points obtained by simulation is in good agreement with the meas-ured values.In the simulation of layered pouring,the vertical compressive stress of dam heel caused by self-weight is 7.32 MPa,and the vertical compressive stress of dam heel caused by one-time application of self-weight is 7.70 MPa.The temperature load during the construction period causes the vertical compressive stress increment at the observation dam heel,and the maximum value is 1.1 MPa.[Conclusion]The result show that the application method of self-weight load has little effect on the dam heel stress of gravity dam,and the vertical compressive stress of dam heel caused by layered pouring self-weight load is slightly smaller than that caused by one-time application of self-weight load.The temperature rise of the dam after the grouting of the longitudinal joint causes the middle block to squeeze the upper block,which leads to a large vertical compressive stress in the dam heel,which can partly explain the reason why the measured heel stress of gravity dam is mostly large compressive stress.
万方数据
维普
