某大型泵站空箱隔墩不均匀沉降敏感度分析

Sensitivity Analysis of Non-uniform Settlement of Empty Box Pier in Large Pumping Station

鉴于泵站复杂的进出水流道及泵房结构受力特殊,裂缝普遍存在,直接影响建筑物安全有效服役。以某大型贯流泵站高程9.7m变频器层空箱处混凝土隔墩裂缝工程为例,采用回弹值测法、碳化深度检测、钢筋保护层厚度测定及混凝土钻芯取样测试裂缝区域混凝土病害程度,并采用计算机仿真分析,基于有限单元法,依托泵站运行期垂直位移观测数据,考虑温度变化分析了基础不均匀沉降引发裂缝敏感度。结果表明,在泵站空箱隔墩实际裂缝区域出现应力集中,其结果与实际混凝土开裂区域吻合,说明基础不均匀沉降影响了泵站裂缝发展。因此,泵站设计过程中应考虑基础不均匀沉降问题。

The complicated flow way, special structure of pump room and common cracks of pumping station directly affect the safe and effective service of the building. Taking the concrete pier cracks in the empty box at the elevation 9.7 m frequency converter of a large intersecting pump station as an example, the rebound value method, the depth of carbonization, the thickness measurement, coagulation of the steel bar protection layer, and the soil drill core sample were used to test the degree of concrete disease in the crack area, and the computer simulation analysis was carried out. Based on the finite element method, relying on the observation data of the vertical displacement of pumping station during operation period as well as considering temperature change, the fracture sensitivity caused by the uneven settlement of the foundation was analyzed. The results show that the stress concentration appears in the actual crack area of the empty box pier in pumping station. It is in agreement with the actual concrete cracking area, which indicates that the uneven settlement of the foundation affects the development of the crack in pumping station. Therefore, the foundation uneven settlement should be considered during the design of pumping station.