葛洲坝二江泄水闸预应力闸墩的工作性态

Working status of the 2nd channel sluices'prestressed concrete piers at the Gezhouba Project

葛洲坝工程在国内率先采用了大吨位预应力闸墩承受闸门巨大水推力。安装埋设了大量测力计、钢筋计、应变计等监测仪器，取得了大量的观测资料。对葛洲坝工程二江泄水闸预应力闸墩运行十年来的观测资料进行了分析。分析结果表明：预应力损失主要发生在施工期。运行期预应力的年均损失率，各测力器平均为０．４５％，其中最小的为０．０３％，最大的为１．０４％。运行以来，各测力器显示的预应力总损失率，平均为１４．０５％，超过了设计预计值（１２％）。但颈部混凝土处于受压状态，预应力仍维持较高水平。预应力闸墩的工况是正常的。

In China,the Gezhouba Project is the first one to adopt prestressed concrete peirs with large tonnage capacity,to bear huge water thrust from the gates.For the purpose of monitoring the working status of these peirs,a great number of electric dynamometers,reinforcement meters and strain gages were installed, and a lot of observation data has been obtained.The analysis is carried out with observation data of ten years since commission of the sluice.Analytical results show that the prestressing loss occurs mainly during construction period;annual average prestressing loss rate.of various dynamometers during operation period amounts to 0.45%,with minimum loss rate of 0.03% and maximum loss rate of 1.04%;since beginning of operation,the total prestressing loss rate indicated by various dynamometers amounts to 14.05% in average,which exceeds anticipated value of 12% However,the concrete's stresses at the necks of the piers are all in compression status,and the prestresses maintain in a state of higher level.The working status of prestressed piers is normal.