热带地区碾压混凝土重力坝温控仿真分析

Simulation Analysis of Temperature Control of Roller Compacted Concrete Gravity Dams in Tropical Zone

鉴于热带地区气温具有全年较高且变幅小、无四季之分的特点,因此热带地区大坝与其他地区大坝相比,其温度场和应力场存在较大差异,关键的温控部位与时段也不相同,常规的温度控制标准不再适用。以位于热带地区的柬埔寨额勒赛水电站碾压混凝土重力坝为例,采用三维有限元法分析了#5挡水坝段的温度场与温度应力场数值及分布规律,明确了大坝温控的关键部位与时段,制定了满足大坝施工与安全运行要求的温度控制标准与相应的温控措施,并对#8溢流表孔坝段施工期安全度汛问题进行了分析。结果表明,坝体应力控制部位主要是基础约束区,控制时段主要是坝体蓄水时期以及正常运行期;在温控措施条件下,溢流表孔坝段可安全度汛。

The temperature and stress field of the dams in tropical areas have large difference with them in conven- tional regions because its air temperature has special features, such as keeping high around the year with small amplitude, maintaining relatively stable, without distinguish of seasons. The crucial parts and periods and standards of temperature control also changes compared with the dams in conventional regions. The temperature control standard also need to be modified. Taking roller compacted concrete gravity dam of Kampuchea Elesai Hydropower Station that constructed in tropical area for an example, the numerical and distribution regularities of # 5 dam＇s temperature field and thermal stress field have been analyzed. The key parts and periods of the dam＇ s temperature control have been clarified. The dam＇ s temperature control standards which can satisfy the requirements of dam construction and safe operating have been formulated and corresponded temperature control measures have been put forwarded. The analysis of the safety of the hole section during flood season in the construction stage is also carried out. The results show that the key parts of the dam＇s stress control is in foundation restraint area and the mainly control period is dam storage time and normal operation period; under the condition of temperature control measures, flood control can be implemented safely by overflow hole of the dam section.