软弱地层锚索预应力蠕变损失研究

Creep Loss Research of Anchor Prestressing in Soft Ground

多个工程实例表明:岩土体蠕变易引起锚固工程支护结构加固频繁、锚索重新张拉等工程病害,严重者导致锚固力失效,锚固工程失稳,如若处理不当,将直接危及施工人员的生命财产安全;本文以济南市某深基坑工程案例为依托,将岩土体由经典的广义Kelvin体代替,推导了其本构方程、蠕变方程、松弛方程,从理论上分析了锚索蠕变变形对预应力损失的贡献大小;并结合现场测试数据对比可知:该模型能够较好的反映蠕变变形引起的损失趋势,由数据软件拟合公式可知,理论计算结果与测试数据偏差不大,论证了上述分析的可靠性,为今后锚固工程的设计、施工提供了理论依据和技术支持。

Through collating and analyzing the existing data of engineering examples,rock creep can lead the anchorage support re-tensioned and repaired frequently,which could further result in the failure of the anchoring force and the instability of the anchor project; If it should not be handled properly,the life and property safety of construction workers were endangered; One deep pit of Jinan City was taken as an example,the creep calculation model was replaced as general Kelvin,the corresponding constitutive equations,creep equation,relaxation equation were deduced; The theoretical calculation of the anchor prestressing loss which result of creep deformation was analyzed; Comparison of theoretical calculation result and field test data shows that： the creep calculation model can better reflect the cable prestressing loss trends;the fitting formula demonstrated the reliability of the above analysis; it provided a theoretical basic and technical support for the design and construction of similar anchor project in the future.