兰州新区湿陷性黄土地基处理

中铁第一勘察设计院集团有限公司,陕西 西安 710043

湿陷性黄土; 地基处理; 换填; 冲击碾压

Loess foundation treatment for Lanzhou new district
CHEN Hai-jun

(China Railway First Survey and Design Institute Group Ltd,Xi'an 710043,China)

collapsible loess; ground treatment; filling; impact rolling

备注

工程界对于黄土湿陷性的研究和应用日趋完善,不仅对其影响因素进行分析,并且对其进行二元结构本构模型分析和采动厚湿陷性黄土破坏数值模拟研究。主要探讨了湿陷性黄土的工程处理措施。根据黄土湿陷性的特点,依托兰州新区市政道路的工程地质情况,分析判定了黄土的湿陷等级和处理深度,总结归纳了本地区湿陷性黄土地基处理的各种方案,即在一般黄土地区路段,预防为主,防止路基俩侧积水,对积水洼地和地表裂缝进行填平、夯实,道路两侧排水沟渠进行防渗加固。在重要路段,采取以下几种处理方案加以处理:换填灰土垫层法、重锤夯实法、冲击碾压法、强夯法以及孔内深层强夯法,详细介绍了这几种方法的加固机理、适用的情况、检测方法以及优缺点进行了讲述,并对灰土换填法灰土衰减机理的分析引申到工程的检测评定指标以及湿陷性黄土地基处理方案的有机合理叠加。根据拟建工程的实际情况,新区市政道路工程对各级湿陷性黄土采用了路床灰土换填及灰土底面以下翻挖重新压实或冲击碾压的有机结合的地基处理方案,达到了资源整合经济合理有效利用的目的 ,收到了预期的经济效益、环境效益和社会效益,并对湿陷性黄土地区的地基处理具有一定的借鉴意义。

This paper discusses the loess treatment measures.According to the characteristics of loess collapsibility,relying on the Lanzhou New District road engineering geology,analytically determined the collapsibility grade and depth of treatment,summarized the various programs for the region's collapsible loess foundation treatment,that is, in the general section of the loess region,focusing on prevention,to prevent water roadbed both sides, the water surface depressions and cracks filled,compacted,and both sides of the road drainage ditches be imperviously reinforce.In the important sections,take the following treatment options:Replacement lime cushion method,tamping method,impact rolling method,dynamic compaction and hole dynamic compaction Details of the reinforcement mechanism of these methods,the detection methods and the advantages and disadvantages were elaborated,analysis of the dust attenuation mechanism replacement method extended to the detection assessment indicators and organic reasonable superposition of loess foundation treatment programs.According to the actual situation of the proposed project,the district road works on all levels of collapsible loess wet road bed adoptedthe organic combination of foundation treatment program of lime soil and dust filled and the underside re-rolling compaction or impact,achieving a rational and efficient use of economic resources,receiving the anticipated economic,environmental and social benefits,with a certain significance for the collapsible loess foundation treatment treatment.