安康膨胀土地区基坑边坡失稳特点分析及防治措施研究

ANALYSIS OF INSTABILITY CHARACTERISTICS OF FOUNDATION PIT SLOPE AND DISCUSSION ON PREVENTION AND CONTROL MEASURES IN ANKANG EXPANSIVE SOIL AREA

安康地区膨胀土具有保水性强、吸水膨胀、吸水抗剪强度变小、失水收缩等特点。本研究对安康膨胀土地区某项目基坑边坡破坏特征进行了分析,进一步印证了膨胀土受水膨胀是基坑边坡破坏的根本原因,在雨天条件下边坡坡脚防护不严、坡顶支护和硬化路面裂缝形成的渗水通道是膨胀土基坑边坡破坏的直接原因,其中坡脚封闭不严是基坑边坡破坏的首要原因。本研究提出预防水对坡体造成破坏的施工措施及出现坡体失稳后的治理措施。

From the composition of expansive soil in Ankang area,it has the characteristics of strong water retention,water swelling,water absorption and shear strength greatly reduced,water loss and shrinkage.Based on the analysis of the failure characteristics of the foundation pit slope of a project in the expansive soil area of Ankang,it is further proved that the expansion of expansive soil by water is the fundamental reason for the failure of the foundation pit slope,under the condition of rainy day,the seepage passage formed by the weak protection of the slope foot,the support of the slope top and the crack of the hardened road surface is the direct cause of the slope failure of the expansive soil foundation pit,and the primary cause of the slope failure is the weak closure of the slope foot.The construction measures to prevent the destruction of slope caused by water and the treatment measures after the failure of slope are put forward.