压力分散型锚索与拉力集中型锚索抗振性能研究

Research on anti-vibration ability of pressure dispersed anchor cable and tension concentrated anchor cable

京石客运专线石家庄明挖隧道工程与既有京广铁路线近距离并行长达5 km,为了摸清列车动载对桩锚支护结构的影响,以及不同锚固形式对动载的响应特点,特在该隧道设立压力分散型锚索试验段,与现场普遍采用的拉力集中型锚索锚固段相对照,进行长期应力、应变量测。在此基础上,对实测数据进行了系统的整理和分析,对比了压力分散型锚索与拉力集中型锚索在应对动载方面的不同特性。研究表明,压力分散型锚索的抗振性能是拉力集中型锚索的5倍,而且具有应力调整时间短、长期抗振性能稳定,预应力损失幅度小、比例低的优点。

In the engineering of Passenger Dedicated Line from Beijing to Shijiazhuang, a 5 krn long tunnel parallel to the existing Jing-Guang railway line with a distance ranging from 5 m to 20 m was built with open cut method. A testing length supported with pressure dispersed anchor cables was designed and constructed to compared with the commonly used tension concentrated anchor cables on both dynamic response and anchorage effect. Based on data measured for half a year on site, the research on performance and character of these two kinds of anchor cables was made. It is proved that the anti-vibration ability of the pressure dispersed anchor cable is 5 times stronger than the tension concentrated anchor cable. Furthermore, the former has advantages of shorter stress transfer time, stable anti-vitration of long period, less loss of prestress.