后张法预应力施工伸长值的影响因素与控制方法  

INFLUENCING FACTORS AND CONTROL METHODS OF POST-TENSIONING PRESTRESS CONSTRUCTION ELONGATION VALUE

作　　者：石会超 SHI Hui-chao(Beijing Construction Engineering Group Co.,Ltd.,100055,Beijing,China)

机构地区：[1]北京建工集团有限责任公司,北京100055

出　　处：《建筑技术》2021年第8期1017-1020,共4页Architecture Technology

摘　　要：当前在后张法预应力张拉过程中,多采用预应力筋伸长值作为校核预应力施加效果的手段,阐述后张法预应力筋实际伸长值的测量方法;采用单因素敏感性分析法分析现行规范计算公式中各参数变化一定幅度时伸长值变化的程度,揭示伸长值对不同参数影响的敏感程度;从钢束理论伸长值计算、孔道和预应力筋安装、张拉设备及张拉操作过程四个方面分析影响伸长值的因素;对各因素在施工中控制的重要程度进行分级得出准确的预应力筋实际伸长值,以更好地校核桥梁结构的预应力施加状态,确保后张法预应力施工质量。At present,in the post-tensioning prestressing process,the elongation value of the prestressing tendon is often used as a means to check effect of prestressing,and the measurement method of the actual elongation value of the post-tensioning prestressing tendon is explained;single factor sensitivity analytical method is adopted to analyze the change degree of elongation value when each parameter in the current standard calculation formula changes by a certain range,which reveals sensitivity of the elongation value to influence of different parameters;from four aspects of calculation of theoretical elongation value of steel strand,installation of channel and prestressed tendon,tensioning device and tensioning operation,the factors affecting the elongation value are analyzed;the importance of each factor in the construction is classified to obtain an accurate actual elongation value of the prestressed tendons,so as to better check state of applied pre-stress of bridge structure to ensure quality of post-tensioning pre-stress construction.

关 键 词：后张法 预应力张拉 预应力筋伸长值 

分 类 号：TU74[建筑科学—建筑技术科学]