高寒地区碾压混凝土坝岸坡坝段保温方案研究

Feasibility analysis of heat preservation for RCC dam abutment monoliths in cold regions

高寒地区某碾压混凝土重力坝岸坡坝段,原温控设计提出在上、下游面采用喷涂12cm厚聚氨酯进行永久保温。根据工地现场左右岸坝段开挖较深的实际情况,对原上、下游面的保温方案进行了优化,提出对上、下游面喷涂聚氨酯结合填土的保温方案,但在回填填土前,应对坝体上下游面、浇筑水平层面做好临时保温工作,临时保温采用3cm厚聚氨酯发泡被。三维有限元仿真计算结果表明,本方案能达到较好的越冬保温效果,有效防止上、下游面表面裂缝的产生,且施工方便、节约投资,可为类似工程的保温提供借鉴。

According to the original design of temperature control for the left and right abutment monoliths of a RCC dam which is situated in a cold region, a 12cm thick layer of polyurethane would be sprayed on the upstream and downstream surfaces of the monoliths for the purpose of heat preservation. In the actual constructing process the monoliths were constructed after very deep excavation. By optimizing the original temperature control design, the authors put forward a new scheme for heat preservation to combine earthfilling with spraying polyurethane. Before earth-filling, the upstream and downstream surfaces should be temporally protected with a 3cm thick foaming cover of polyurethane. A calculation was made by applying a 3-D finite element method. The results show that the recommended scheme for heat preservation can get good effect by decreasing the thermal stresses of the upstream and downstream surfaces. The cracks on the surfaces can be effectively prevented. It can be used as a reference for other similar projects.