Study on Temperature Control and Crack Prevention of Concrete Lining for the Non-pressure Spillway Tunnel of Dashixia Water Control Project in Xinjiang
Under the long-term scouring effect of high-speed water flow,once cracks occur in the concrete lining of the spillway tunnel,it will inevitably cause cavitation damage to the flow surface,thereby affecting the normal and stable operation of the project.Therefore,it is of great significance to conduct temperature control and crack prevention study on the lining concrete of the spillway tunnel.Based on the flood discharge and sediment discharge tunnel project of the Dashixia water control project,the three-dimensional finite element method is used to calculate and analyze the changes in temperature and temperature stress of the lining concrete of the flood discharge tunnel under different temperature control measures.The suitability of different temperature control measures is demonstrated.The results show that spray watering measures have a certain effect on improving the temperature stress on the surface of lining concrete,and have a significant inhibitory effect on concrete shrinkage cracks;water cooling measures mainly focus on improving the temperature and stress conditions inside the lining concrete,but will prompt untimely occur-rence of the cooling process,which increases the risk of early cracking.Therefore,the concrete cooling rate and early cooling amplitude should be strictly controlled during the construction process.This study recommends that the concrete cooling rate be controlled to not exceed 2.0～2.5℃/d;both the early stages of construction and low temperature periods in winter are prone to occurrence of cracks.Combining winter insulation measures with cooling measures during construction can achieve better results.The study results of this paper can provide reference for the design and construction of temperature control and crack prevention measures for concrete lining of similar flood-discharge tunnel projects.
spillway tunnellining concretetemperature control and crack preventionfinite element analysis
万方数据
维普
