消防管线卡箍接头抗震性能试验研究

Experimental study on seismic performance of grooved fit joints of fire sprinkler piping system

消防管线系统是建筑中关键的非结构构件之一,为了保障建筑在强震后免受火灾的威胁,必须保证其正常使用功能。本文通过12组拟静力试验研究了消防管线系统中常用的两种卡箍接头的力学性能、转动能力及破坏模式,两种接头型式为DN150弯管接头和DN150转DN80的三通接头。结果表明卡箍断裂和水管被拔出是主要破坏模式,与接头处连接的镀锌钢管有轻微磨损,但不会造成大规模泄漏。在50%超越概率下,泄漏极限状态对应的转动能力分别为0.064 2 rad(DN150弯管接头)、0.089 1 rad(三通接头的DN150侧)和0.217 4 rad(三通接头的DN80侧),因此弯管接头是消防管线系统中的薄弱环节,应采取措施避免地震中过大的变形。

Pressurized fire sprinkler piping system is one of the most critical nonstructural systems in a building. Its operational function must be maintained after a very strong earthquake to prevent the subsequent fire disaster. Twelve grooved fit joints were tested quasi-statically to investigate their mechanical behavior, the rotational capacity and the failure mode. These joints are categorized into two groups, namely DN150 elbow joints and DN150 to DN80 Tee joints. The test results show that the fracture of the grooved fitting and the pull-out of pipes from the grooved fitting are the major damage patterns. Although slight abrasion and wear were observed on the contact surface between the galvanized steel pipe and the grooved fitting, they would not result in significant leakage. At the 50% exceedance probability, the rotation capacity corresponding to the leakage limit state is 0.064 2 rad, 0.089 1 rad and 0.217 4 rad for the DN150 elbow joint, the DN150 connection of Tee joint, and the DN80 connection of Tee joint, respectively. Therefore, the elbow joints are the weak points of the fire sprinkler piping system. Larger deformation than the leakage limit state of 0.064 2 rad shall be avoided during a strong earthquake.