【作者】 魏松涛；

【导师】 郝培文；

【作者基本信息】 长安大学 ， 道路与铁道工程， 2007， 硕士

【摘要】 由于沿黄冲湖积平原地区地质的特殊性,沿线路基下经常存在不同厚度的软弱土层,这极大地影响了道路的长期稳定和安全使用。因此,冲湖积平原软弱地基处治措施及沉降问题的研究对沿黄地区道路的建设十分重要。本文在对银川绕城高速公路沿线软弱地基进行地质、水文调查和室内土工试验的基础上,研究并总结了冲湖积平原软弱土的结构性状及工程特性;结合工程实践,对换填砂砾垫层、袋装砂井、挤密砾石桩三种处治措施进行了深入、细致的分析,总结了不同处治措施的适用范围、加固机理、设计方法、施工工艺及相关施工参数;然后采用土工离心模型试验,研究了三种不同处治措施地基的沉降变形规律,分析了处治效果,优化了设计参数,预测了软弱地基的最终沉降;并通过施工监测的沉降、地基土体水平位移、孔隙水压力等资料,对银川绕城高速公路软弱地基的处治效果进行了经济性分析。最后,研究结果表明:采用换填砂砾垫层、袋装砂井、挤密砾石桩三种技术能有效加固冲湖积平原的软弱地基并减小沉降,是合理有效的地基处理措施。同时也对冲湖积平原软弱地基处治提出了建议,为今后该地区的高速公路建设积累了经验。更多还原

【Abstract】 As the special geology property of alluvial-lacustrine deposits plain along the Yellow River, there often exists the different thickness soft-weak soil layer under the roadbed along the road, which affect the highway’s long-term stability and safety usage. Study on the foundation treatment technique and settlement problem of alluvial-lacustrine deposits plain’s soft-weak soil is essential to the road way construction of area along the Yellow River.On the base of extensive geological, hydrological survey and soil experiment for the soft-weak soil along the Yin Chuan Ring Expressway, the paper studies and summarize the structure property and engineering property of alluvial - lacustrine deposits plain’s soft-weak soil; And analyses and studies the applicability, reinforce mechanism, design method, construction technology and related construction parameters of three treatment methods, such as, Replacement of the Gravel Cushion, Sand-wick, Gravel Compaction Pile; Then, through the geotechnical centrifuge model tests, the paper studies the settlement rules of the foundation treated by three treatment methods, analyses the treatment effect, optimizes the design parameters, predicts the final settlement of the soft-weak foundation; And through monitoring construction settlement, soil horizontal displacement, pore water pressure etc., the paper gives a economical analysis of the Yin Chuan Ring Expressway’s soft-weak foundation treatment effect.Finally, the results shows: three treatment methods, Replacement of the Gravel Cushion, Sand-wick, Gravel Compaction Pile have been adopted, which can reinforce alluvial -lacustrine deposits plain’s soft-weak foundation and reduce settlement, they are reasonable and effective methods to deal with the foundation.At the same time, the treatment methods of alluvial-lacustrine deposits plain’s soft-weak foundation is put forward and it can guide expressway construction on this area for later.更多还原