预应力锚索对大跨度扁平地下洞库开挖稳定的影响研究

为研究预应力锚索对大跨地下工程开挖稳定的影响,以大跨度扁平地下洞库开挖稳定为例,采用数值模拟的方法对锚索预应力值和间距两个因素进行分析研究,获得不同锚索预应力值和间距下地下工程的拱顶位移、衬砌最大主应力的分布规律,结果表明:随着锚索预应力值的增加,拱顶位移、衬砌最大主应力在逐渐降低,而锚索最大应力呈现先增加后减小的趋势;随着锚索间距的增加,拱顶位移、衬砌最大主应力在逐渐升高,而锚索最大应力同样呈现先增加后减小的趋势;建议锚索预应力值取200 t、间距取5 m较为适宜。

Research on the effect of prestressed cable on excavation stability of large-span underground engineering

In order to analyze the effect of prestressed cable on the excavation stability of super-span underground engineering, taking a large span underground engineering as the example, the prestress value and space of prestressed cable were analyzed by numerical simulation. The principle of vault displacement and liner maximum principal stress under different prestress value and space of prestressed cable were obtained. The results show that with the increase of the anchor cable prestress the vault displacement and liner maximum principal stress decrease gradually, however, the maximum stress of the anchor cable shows a trend of increasing at first and then decreasing. With the increase of the space of anchor cable, the vault displacement and liner maximum principal stress increase gradually, the maximum stress of the anchor cable shows a trend of increasing at first and then decreasing. It is recommended that the prestress value of the anchor cable should be 200 tons and the space should be 5 m.