新疆下坂地水库大坝上游围堰基础振冲加固处理

饱和软土具有高压缩性、高灵敏度、高流变性和低强度、低渗透系数的工程特性，因此在软基上施工而临着孔压高、变形大、承载力低的难题。针对新疆下坂地工程上游围堰基础下伏地层中的软饱和层的特点，介绍了对基础淤泥质粘土层进行振冲处理的方法，以及振冲碎石桩的设计、施工和质量检测的过程。振冲碎石桩在下坂地围堰基础处理上的成功应用，打破了认为振冲碎石桩不适宜加固不排水抗剪强度小于20kPa的软弱粘土的一般看法，为振冲法在软基筑坝领域更为广泛的推广应用提供了成功的工程实例。

Reinforce Treatment of Vibration for Upstream Cofferdam of Xinjiang Xiabandi Reservoir Dam

Soft saturated soil has a practical characteristics of high-compression, high sensitivity, high flow variability and low-intensity, low-permeability coefficient. So the construction on soft ground is faced with the problem of high-pore pressure, high-deformation, low capacity. The paper elaborates the vibro-method which is used as the treatment of muddy-clay layer, the design, construction and quality inspection process of the vibroflotation crushed stone pile in the upstream cofferdam foundation of Xiabandi project whose underlying strata has the characteristics of soft saturated soil. The successful application of the vibroflotation crushed stone pile in Xiabandi project challenges the typical opinion that the vibroflotation crushed stone pile is not suitable for the soft clay whose undrained shear strength is less than 20 kPa,has provided examples of successful projects for more extensive application of vibro-method in the field of building dam on soft basis.