石灰桩处理岛状多年冻土地基现场试验研究
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摘要
研究目的:作为一种较为成熟的地基处理方法,石灰桩主要应用于加固软土地基、湿陷性黄土地基、道路路基加固以及纠偏加固危房等方面,对其加固原理已开展了较多研究。但利用石灰桩的放热作用来处理高温岛状冻土地基,相关研究较少。本文通过现场试验,从地温、变形、承载力三个方面对石灰桩处理岛状多年冻土的应用效果进行评价,并对石灰桩处理高温岛状冻土地基的施工工艺进行总结。研究结论:(1)石灰桩处理冻土地基时,关键要注意控制配料的质量,确定合适的含水率,保证配料拌和夯填的连续性;(2)桩径40 cm、桩间距1.2 m条件下,生石灰含量50%的石灰桩能在施工后一周内完全融化桩周冻土且地基土达到最高温;(3)石灰桩复合地基变形在施工后一周内基本完成,试验测得地基土和桩的变形以竖向膨胀为主,石灰桩的膨胀挤密基本消除了冻土融化可能产生的融沉;(4)利用石灰桩处理岛状多年冻土地基能达到融化冻土、加固融土的效果,试验研究成果可为石灰桩处理岛状冻土的实际工程提供借鉴。
Research purposes:As a kind of common engineering resistance measures,lime pile mainly had been used to treat soft soil foundation,collapsibility loess foundation,and rectification of building.And the strengthening principle had been deeply studied on those fields.But few people study how to use lime pile to treat foundation in island-shaped frozen soil.In this paper,the results of lime pile in island-shaped frozen soil are proven by ground temperature,foundation deformation and bearing capacity of foundation and the construction technology is summarized for treating foundation in island-shaped frozen soil.Research conclusions:(1) When use lime pile to treat foundation in island-shaped frozen soil,the quality of lime must be controlled,the water content must be determined through test,and the mixture should be tamped quickly.(2) When the pile diameter is 40 cm,the pile spacing is 120 cm,and the lime content is 50%,the frozen soil has completely melted in a week.(3) The foundation deformation finishes also in a week and it is vertical expansion mainly,that means the settlements which caused by frozen soil thawing are offset by the expansive of lime pile.(4) Use lime pile can make permafrost thawed and improve foundation.The research results can further provide reference for lime pile in island-shaped frozen soil in the future.
Research purposes:As a kind of common engineering resistance measures,lime pile mainly had been used to treat soft soil foundation,collapsibility loess foundation,and rectification of building.And the strengthening principle had been deeply studied on those fields.But few people study how to use lime pile to treat foundation in island-shaped frozen soil.In this paper,the results of lime pile in island-shaped frozen soil are proven by ground temperature,foundation deformation and bearing capacity of foundation and the construction technology is summarized for treating foundation in island-shaped frozen soil.Research conclusions:(1) When use lime pile to treat foundation in island-shaped frozen soil,the quality of lime must be controlled,the water content must be determined through test,and the mixture should be tamped quickly.(2) When the pile diameter is 40 cm,the pile spacing is 120 cm,and the lime content is 50%,the frozen soil has completely melted in a week.(3) The foundation deformation finishes also in a week and it is vertical expansion mainly,that means the settlements which caused by frozen soil thawing are offset by the expansive of lime pile.(4) Use lime pile can make permafrost thawed and improve foundation.The research results can further provide reference for lime pile in island-shaped frozen soil in the future.
引文
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[4]丁靖康,韩龙武,徐兵魁,等.多年冻土与铁路工程[M].北京:中国铁道出版社,2011.Ding Jingkang, Han Longwu, Xu Bingkui, etc.Permafrost and Railway Engineering[M]. Beijing:China Railway Publishing House,2011.
[5]陈东丰,郑纯宇,钱劲松,等.用于岛状冻土地区路基换填的新型材料及其性能[J].公路交通科技,2016(6):40-45.Chen Dongfeng,Zheng Chunyu,Qian Jinsong,etc.New Subgrade Replacement Materials for Segregated Frozen Ground Area and Their Properties[J]. Journal of Highway and Transportation Research and Development,2016(6):40-45.
[6]顾世安,顾长青.热棒在岛状冻土路基中的应用[J].低温建筑技术,2009(8):100-102.Gu Shian, Gu Changqing. Heat Pipes Applied in Subgrade in Patchy Permafrost[J]. Low Temperature Architecture Technology,2009(8):100-102.
[7]韩皓,蔡力,侯芸,等.高寒地区岛状冻土软土地基处理研究[J].内蒙古公路与运输,2001(67):7-10.Han Hao,Cai Li,Hou Yun,etc. Study on Theory and Methods for the Treatment of Soft Ground for Islandtype Frozen Soil in High and Cold Area[J]. Highways and Transportation in Inner Mongolia,2001(67):7-10.
[8]赵福宁,赵雨军.强夯置换法在岛状冻土特殊路基处理中的应用[J].铁道建筑,2014(10):85-87.Zhao Funing, Zhao Yujun. Application of Dynamic Compaction Replacement Method to Treat Special Subgrade in Island-shaped Frozen Soil[J]. Railway Engineering,2014(10):85-87.
[9]曹玉新,魏庆朝.青藏铁路多年冻土地区桩基础设计研究[J].铁道工程学报,2004(2):127-133.Cao Yuxin,Wei Qingchao. Study on Design of Pile Foundation in Permafrost Area on Qinghai-Tibet Railway Line[J]. Journal of Railway Engineering Society,2004(2):127-133.
[10]金兰,程佳,孟进宝,等.石灰桩融化岛状多年冻土的试验研究[J].铁道标准设计,2017(12):1-5.Jin Lan,Cheng Jia,Meng Jinbao,etc. Experimental Study on the Lime Pile Thawing the Patchy Permafrost[J]. Railway Standard Design,2017(12):1-5.
[11]王兴,熊治文,程佳,等.石灰桩对冻土地基预融效果模型试验研究[J].铁道标准设计,2018(4):22-26.Wang Xing, Xiong Zhiwen, Cheng Jia, etc.Experimental Research on Effect of Lime Pile on Prethawing of Permafrost Foundation[J]. Railway Standard Design,2018(4):22-26.
[2]宋新生.岛状多年冻土路基差异沉降影响因素研究[J].施工技术,2011(36):85-89.Song Xinsheng. Influence Factors on Differential Settlement of Island Permafrost Subgrade[J].Construction Technology,2011(36):85-89.
[3]张玉强.内蒙古岛状冻土地区公路路基施工技术研究[D].天津:天津大学,2008.Zhang Yuqiang. Study of Highway Subgrade Construction Technology in the Segregated Frozen Ground Area in Inner Mongolia[D]. Tianjin:Tianjin University,2008.
[4]丁靖康,韩龙武,徐兵魁,等.多年冻土与铁路工程[M].北京:中国铁道出版社,2011.Ding Jingkang, Han Longwu, Xu Bingkui, etc.Permafrost and Railway Engineering[M]. Beijing:China Railway Publishing House,2011.
[5]陈东丰,郑纯宇,钱劲松,等.用于岛状冻土地区路基换填的新型材料及其性能[J].公路交通科技,2016(6):40-45.Chen Dongfeng,Zheng Chunyu,Qian Jinsong,etc.New Subgrade Replacement Materials for Segregated Frozen Ground Area and Their Properties[J]. Journal of Highway and Transportation Research and Development,2016(6):40-45.
[6]顾世安,顾长青.热棒在岛状冻土路基中的应用[J].低温建筑技术,2009(8):100-102.Gu Shian, Gu Changqing. Heat Pipes Applied in Subgrade in Patchy Permafrost[J]. Low Temperature Architecture Technology,2009(8):100-102.
[7]韩皓,蔡力,侯芸,等.高寒地区岛状冻土软土地基处理研究[J].内蒙古公路与运输,2001(67):7-10.Han Hao,Cai Li,Hou Yun,etc. Study on Theory and Methods for the Treatment of Soft Ground for Islandtype Frozen Soil in High and Cold Area[J]. Highways and Transportation in Inner Mongolia,2001(67):7-10.
[8]赵福宁,赵雨军.强夯置换法在岛状冻土特殊路基处理中的应用[J].铁道建筑,2014(10):85-87.Zhao Funing, Zhao Yujun. Application of Dynamic Compaction Replacement Method to Treat Special Subgrade in Island-shaped Frozen Soil[J]. Railway Engineering,2014(10):85-87.
[9]曹玉新,魏庆朝.青藏铁路多年冻土地区桩基础设计研究[J].铁道工程学报,2004(2):127-133.Cao Yuxin,Wei Qingchao. Study on Design of Pile Foundation in Permafrost Area on Qinghai-Tibet Railway Line[J]. Journal of Railway Engineering Society,2004(2):127-133.
[10]金兰,程佳,孟进宝,等.石灰桩融化岛状多年冻土的试验研究[J].铁道标准设计,2017(12):1-5.Jin Lan,Cheng Jia,Meng Jinbao,etc. Experimental Study on the Lime Pile Thawing the Patchy Permafrost[J]. Railway Standard Design,2017(12):1-5.
[11]王兴,熊治文,程佳,等.石灰桩对冻土地基预融效果模型试验研究[J].铁道标准设计,2018(4):22-26.Wang Xing, Xiong Zhiwen, Cheng Jia, etc.Experimental Research on Effect of Lime Pile on Prethawing of Permafrost Foundation[J]. Railway Standard Design,2018(4):22-26.