云南昭通膨胀土工程地质特征及路基处理

Engineering geological characteristic and roadbed treatment of the expansive soil in Zhaotong Basin,Yunnan Province

文章论述了云南昭通盆地膨胀土的工程地质特征、物理力学特征和膨胀性指标,对云南昭通盆地膨胀土地基进行了综合评价,分析了国道213线昭通-麻柳弯汽车专用二级公路膨胀土填土路堤及挡墙向外滑移和纵向开裂的产生原因,并结合具体的工程实践,对昭通地区公路工程的膨胀土灾害提出了采取设置土质台阶,放缓边坡;采用纵横向盲沟排水,采用地基帷幕隔绝沟水渗入地基,采用土工膜隔绝地表水;设置钢筋混凝土轻型挡墙,并采用土工格栅与路堤相连接,选用填料砂性土或碎石土等综合措施进行处理的路基处理方案,以及膨胀土地区进行公路路基施工的原则。该处理方法为云南省首次采用,对膨胀土地区公路的勘察、设计、施工有一定的参考价值。

The engineering geology characteristic, the physical and mechanical characteristic and the swellability index of expansive soil in Zhaotong Basin. Yunan are discussed in this paper. The author made on the comprehensive evaluation to the expansive soil foundation in Zhaotong Basin, Yunnan analyzed soil and the retaining wall slip outwards on the National automobile. The following measures are put forward： inte the reason that the filling road embankment of expansive Freeway 213 second class highway of appropriation of curved realating soil step, put slow slop for the expansive soil of road engineering in Zhaotong region with idiographic engineering practice. Draining in length and breadth, preventing water into , isolating surface water with geomembrane are adopted. The synthetized scheme of roadbed processings and the principle of roadbed constructing in Zhaotong expansive soil region are concluded, such as setting lightduty of reinforced concrete, connecting with geo-grid and road embankment, choosing sandy soil and broken stone. These transacting measures are adopted for the first time in Yunnan province, so this paper has a certain extent reference and instructional function for investigation, design and construction.