摘要
小浪底水利枢纽工程的３ 条排沙洞， 洞身７０％ 以上采用后张法无粘结预应力混凝土衬砌。其张拉系统的施工主要包括钢绞线的就位、固定， 锚具槽、锚具及张拉设备的安装， 张拉等步骤， 施工工艺严谨。三维有限元分析结果表明， 张拉时锚具槽附近将出现明显的应力集中， 为此， 采取了分步张拉、加箍筋等措施， 达到对预应力的控制， 也避免了产生贯穿性裂缝。为了保证锚索及锚具的防腐、抗磨性， 采用了套管和封闭构件及控制过水面不平整度等措施。小浪底工程排沙洞采用这种衬砌结构的经验可供其他工程借鉴。
In three desilting tunnels of Xiaolangdi Multipurpose Project, over 70% tunnel wall were lined with non cohesive pre stressed concrete by the post tensioning method. The main construction processes of the tensioning system include the location and fixation of steel spiral rope, and the installation of anchorage groove, anchorage device and tensioning equipment. Its construction techniques are strict. According to the three dimension finite element analysis results, it showed that the obvious stress concentration occurs around the anchorage groove during the tensioning. For this reason, the measures of tensioning by stage and adding hoop reinforcement have been adopted to reach the control of pre stresses and avoid the occurrence of through cracks. In order to guarantee the performances of anti corrosion and abrasion resistance of anchorage cable and devices, the measures of casing pipe, closed element and other methods have been adopted. The experience of such lining structure adopted in the desilting tunnels of Xiaolangdi Multipurpose Project can be used in the other projects for reference.
出处
《水力发电》
北大核心
1999年第12期21-23,共3页
Water Power
关键词
排沙洞
后张法
无粘结
预应力混凝土
小浪底工程
desilting tunnel, post tensioning method, non cohesive pre stressed concrete, lining construction, Xiaolangdi Multipurpose Project
