软弱围岩隧道预衬砌支护参数研究  

A Study of the Parameters of the Pre-Lining of a Tunnel in Soft Surrounding Rock

作　　者：杜林林[1] 王秀英 刘维宁[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《现代隧道技术》2013年第5期80-86,共7页Modern Tunnelling Technology

基　　金：国家自然科学基金(51178026)

摘　　要：软弱同岩变形控制是隧道施工中的难题，预衬砌支护在控制软弱围岩变形方面具有显著的优势。采用荷载一结构模型，通过ANSYS计算分析得出了埋深对于预衬砌安全系数具有决定性的影响。为研究合理的预衬砌支护参数，文章分析了30m埋深条件下不同预衬砌厚度、不同钢拱架支撑间距及不同混凝土强度下预衬砌安全系数的变化情况，得出了以下结论：（1）增加预衬砌支护厚度能够有效地提高预衬砌安全系数；（2）预衬砌厚度为30～40cm时，钢拱架对提高预衬砌安全系数作用明显；预衬砌厚度为40～50cm时，钢拱架在提高预衬砌安全系数方面作用较小；（3）混凝土早期强度对预衬砌安全系数影响较大，为获得较高的安全系数，应使用早强混凝土；（4）传统隧道设计方法中围岩荷载不适用于预衬砌工法，预衬砌工法下同岩荷载作用机理有待于进一步研究。Controlling soft surrounding rock deformation has been a challenge in tunneling, but pre-lining support has significant advantages in this situation. By means of a load-structure model, ANSYS ealculations and analysis show that the buried depth has a decisive influence on the safety factor of the pre-lining. To obtain reasonable parameters of pre-lining, the safety factor of pre-linings with different thieknesses, different steel arch spacings, and different eoncrete strengths are analyzed under the eondition of a 30 in buried depth. The results show that （1） thickening the pre-lining can effeetively increase its safety factor; （2） for a pre-lining of 30-40 cm thick, the effect of steel arches on the safety factor is signifieant, while for a 40-50 cm thiek pre-lining, the effect of steel arches on the safety factor is less; （3） the effect of early eoncrete strength on the safety faetor of the pre-lining is rather signifieant, therefore, the early strength eoncrete shall be used to achieve a higher safety faetor; and （4） the load of the surrounding roek in conventional tunnel design methods is not applicable for the pre-lining method and the loading mechanism of surrounding rock in the pre-lining method is pending for further study.

关 键 词：软岩隧道 预衬砌安全系数荷载-结构模型 

分 类 号：U451.4[建筑科学—桥梁与隧道工程]