基于季节性温度变化的波动型边坡锚索预应力定量预测研究

Study on quantitative prediction for fluctuant prestress of slope anchor cable based on seasonal temperature variation

实际工程中,进入运营期后锚索荷载的周期性波动与温度等季节性变化因素密切相关。基于三峡永久船闸高边坡锚固工程监测资料,以温度为主要解释变量,分析温度变化影响预应力的原因,确定温度引起预应力变化的滞后期数,采用主成分分析(PCA)消除各滞后变量间的多重共线性,建立温度和锚索预应力的自回归分布滞后(ARDL)模型,模拟锚索预应力波动变化的过程。回归结果证实,温度对锚索预应力存在显著影响。最后通过预测值与实测值的对比验证模型的有效性,并分析讨论预应力随温度变化的长期过程。

For the anchor cables of operation period in engineering,periodic fluctuation of cable load is closely related to temperature and other seasonal factors. The monitoring data of anchor cables in the high slope of permanent shiplock is uesd to build an ARDL model and simulate the fluctuation of cable load after the steps of using temperature as a main variable,analyzing the reasons for prestress change caused by temperature,finding the logs and using PCA to eliminate multicollinearity between lagged variables. The results show that temperature has a significant effect on anchor cable prestress. Finally,the validity of this model is verified by comparing predicted values with measured values. The long-termed process of prestress change caused by temperature has also been discussed.