摘要
基于有限元分析软件ANSYS,在溪洛渡泄洪洞有压段衬砌混凝土设置垫层的情况下,对不同围岩弹性模量和衬砌厚度进行仿真模拟。通过比较不同衬砌部位,不同点位的最高温度、最大内表温差、早期最大拉应力等,针对围岩弹性模量和衬砌混凝土厚度的变化对衬砌混凝土温度和温度应力的影响进行了分析。研究结果表明,①不同围岩弹性模量下,相同温控措施下衬砌混凝土温度场大致相同。较好围岩会增大早期衬砌混凝土的最大拉应力,减小最小抗裂安全系数,必须采取严格的温控防裂措施,防止早期裂缝。②相同温控措施下,衬砌混凝土越厚,最高温度越高,最大内表温差越大。较薄衬砌混凝土会增大早期衬砌混凝土的最大拉应力,减小最小抗裂安全系数,温控防裂措施要求严格。
In the construction of flood discharge tunnels, we often encounter different types of surrounding rocks, and pour different thicknesses of lining concrete on surrounding rock. Although under the same pouring materials and operating conditions, the temperature and the thermal stress of the lining concrete are also different. Taking Xiluodu flood discharge tunnel as a research object, a 3 -D finite element method is applied to simulate the construction process under conditions of different elastic modulus of surrounding rocks and lining＇s thickness with cushions. Comparing the maximum temperature, maximum temperature difference between inner and surface and maximum tensile stress in the early period, the effects of the change of elastic modulus of surrounding rock and lining ＇s thickness are analyzed. The results show that, （1） The effect of different surrounding rock. , the same pouring materials and operating conditions lead to the same temperature field. The early tensile stress of lining concrete with larger elastic modulus of surrounding rocks is smaller and the late tensile stress is larger. （2）The maximum temperature of thicker lining concrete is higher, so is the maximum temperature difference between inner and surface. From the surface point of lining concrete, the early compressive stresses of thicker lining concrete are larger, and the late tensile stresses of thinner lining concrete are larger. From the inner point of lining concrete, the early compressive stresses of thicker lining concrete are larger, and the late one of thicker lining concrete are larger as the tensile stresses gradually increase.
出处
《中国农村水利水电》
北大核心
2012年第9期124-127,131,共5页
China Rural Water and Hydropower
关键词
泄洪洞
衬砌混凝土
垫层
围岩弹性模量
温度应力
flood discharge tunnel
lining concrete
cushion
elastic modulus of surrounding rock
thermal stress
