土钉墙中土压力探究
|
摘要
土钉墙喷射混凝土面层上受到的土压力大多假设为Rankine主动土压力,但在实际方案中面层却设计很薄,似乎无法承受假定的土压力,这里存在矛盾。文章采用数值实验方法,结合实际工程,对土钉墙面层上受到的土压力、土体内应力在基坑开挖过程的变化进行了评估。分析结果表明,土钉墙面层受到的计算土压力远小于Rankine主动土压力,面层的挡土作用很小。文中提出了在基坑工程等临时性工程中,建议钢筋网加喷射混凝土这样的传统面层改用防水牛津布或彩条帆布等柔性材料来替代,这将一方面发挥面层的作用,另一方面节约投资和减少土钉墙对地下空间产生的不利影响。
The shotcrete facing of soil nailing walls is often assumed to be imposed on by the Rankine's active pressure,but its thickness tends to be designed almost too thin to bear such a big pressure,so the assumed condition is inconsistent with that of the facing in design.By the numerical experiments in deep excavation as well as case studies,the pressure imposed on the facing of soil nailing walls and soil stresses during excavation are explored and estimated in this paper.The analytical results indicate that the lateral earth pressure is the facing subjected to much less than the value determined by Rankine's theory.Its earth-retaining function could be very limited and even neglected.It is recommended that in the provisional engineering such as deep excavation,the flexible waterproof material,for example,canvas,should substitute for the conventional facing layer of steel net plus shotcrete in soil nailing walls to save money and to avoid the side effects on underground space while the functions of the facing layer are still kept.
The shotcrete facing of soil nailing walls is often assumed to be imposed on by the Rankine's active pressure,but its thickness tends to be designed almost too thin to bear such a big pressure,so the assumed condition is inconsistent with that of the facing in design.By the numerical experiments in deep excavation as well as case studies,the pressure imposed on the facing of soil nailing walls and soil stresses during excavation are explored and estimated in this paper.The analytical results indicate that the lateral earth pressure is the facing subjected to much less than the value determined by Rankine's theory.Its earth-retaining function could be very limited and even neglected.It is recommended that in the provisional engineering such as deep excavation,the flexible waterproof material,for example,canvas,should substitute for the conventional facing layer of steel net plus shotcrete in soil nailing walls to save money and to avoid the side effects on underground space while the functions of the facing layer are still kept.
引文
[1]Shen C.K.et al.An in site earth reinforcement lateralsupport system,dept.of civil engineering,University ofCalifornia,Davis,March 1991.
[2]Bridle R.J.Soil Nailing-analysis and design[J].Ground engineering,1989,22(6):52-56.
[3]林宗元主编.岩土工程治理手册[M].辽宁科学技术出版社,1993.(Lin Zongyuan.Handbook ofgeotechnical engineering treatment[M].LiaoningSciencl 8 Technology Press,1993.(in Chinese))
[4]杨育文,袁建新.深基坑开挖中土钉支护极限平衡分析[J].工程勘察,1998,(6):9-15.(Yang Yuwen,Yuan Jianxin.Limit equilibrium method of soil nailingwalls in deep excavation[J].Geotechnical Investigationand Surveying,1998,(6):9-15.(in Chinese))
[5]杨育文.土钉墙空间效应和平滑破坏模式的三维分析[J].岩土力学,2004,25(增2):227-230.(YangYuwen.Analysis and discussion on space effect andtranslational failure of 3D soil nailed walls[J].Rockand Soil Mechanics,2004,25(Suppl.2):227-230.(inChinese))
[6]建筑基坑支护技术规程(JGJ 120-99)[S].北京:中国建筑工业出版社,1999.Technical Specification forRetaining and Protection of Buiding FoundationExcavations(JGJ 120-99)[S].Beijing:ChinaArchitecture and Buiding Press,1999.(in Chinese))
[7]莫暖娇.土钉墙侧向土压力分布研究[J].隧道建设,2006,26(3):1-4(Mo Nuan-jiao,Research ondistribution of lateral soil-pressure in soil-nailed wall[J].Tunnel Construction,2006,26(3):1-4.(inChinese))
[8]Craig R.F.Soil mechanics(6thedition)[M].Sponpress,2002.
[9]赵其华,等.四川汶川县大地震引发的次生地质灾害[J].中国地质灾害与防治学报,2008,19(2):封面3(Zhao Qihua,et al,The secondary geological hazardinduced by the violent earthquake in Wenchuan,Sichuan[J].The Chinese Journal of Geological Hazardand Control,Vol.19,No.2,Cover 3.(in Chinese))
[2]Bridle R.J.Soil Nailing-analysis and design[J].Ground engineering,1989,22(6):52-56.
[3]林宗元主编.岩土工程治理手册[M].辽宁科学技术出版社,1993.(Lin Zongyuan.Handbook ofgeotechnical engineering treatment[M].LiaoningSciencl 8 Technology Press,1993.(in Chinese))
[4]杨育文,袁建新.深基坑开挖中土钉支护极限平衡分析[J].工程勘察,1998,(6):9-15.(Yang Yuwen,Yuan Jianxin.Limit equilibrium method of soil nailingwalls in deep excavation[J].Geotechnical Investigationand Surveying,1998,(6):9-15.(in Chinese))
[5]杨育文.土钉墙空间效应和平滑破坏模式的三维分析[J].岩土力学,2004,25(增2):227-230.(YangYuwen.Analysis and discussion on space effect andtranslational failure of 3D soil nailed walls[J].Rockand Soil Mechanics,2004,25(Suppl.2):227-230.(inChinese))
[6]建筑基坑支护技术规程(JGJ 120-99)[S].北京:中国建筑工业出版社,1999.Technical Specification forRetaining and Protection of Buiding FoundationExcavations(JGJ 120-99)[S].Beijing:ChinaArchitecture and Buiding Press,1999.(in Chinese))
[7]莫暖娇.土钉墙侧向土压力分布研究[J].隧道建设,2006,26(3):1-4(Mo Nuan-jiao,Research ondistribution of lateral soil-pressure in soil-nailed wall[J].Tunnel Construction,2006,26(3):1-4.(inChinese))
[8]Craig R.F.Soil mechanics(6thedition)[M].Sponpress,2002.
[9]赵其华,等.四川汶川县大地震引发的次生地质灾害[J].中国地质灾害与防治学报,2008,19(2):封面3(Zhao Qihua,et al,The secondary geological hazardinduced by the violent earthquake in Wenchuan,Sichuan[J].The Chinese Journal of Geological Hazardand Control,Vol.19,No.2,Cover 3.(in Chinese))
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心