松软倾斜地基填方工程安全性评价方法

松软倾斜地基，有两个特征：一是地基土地松散，具有低强度和可压缩性；二是地基表面或松软层底部，有一定的向外的斜坡。在西南山区铁路公路建设中，多见两类典型的松软倾斜地基；一是斜坡软土，二是松散的岩堆坡地。在松软倾斜地基上填方，随填土荷载增加，土体产生竖向压密变形；在产生竖向压密变形的同时，土体产生横向变形，且变形 范围随填土荷载应力增加而加大，当土体抗剪强度小于填土附加应力产生的横向剪应力时，土体发生剪切破坏，随剪切范围加大地基发生破坏。对于松软倾斜地基，当填土附加应力产生的剪应力大于土体容许剪应力时，应首先考虑采取限制土体侧向变形的侧向约束措施，如锚固桩。

AN DISQUISITION FOR THE SAFETY OF EARTHWORK IN THE FLOOPY - TIP GROUND

The floppy tip ground have two characters,one is that the soil is floppy and the other is that there is a slope on the surface or in the base of the soil.There are two floppy tip ground in the railway and highway construction of China in southwest,one is the slope of soft soil,the other is the slope of rock fill.In the earthwork on a floppy tip ground,the vertical compaction deformation takes place,and as the fill load increase,the transverse compaction deformation will take place in the soil at the same time.For the floppy tip ground,when the shear stress caused by additional stress is bigger than the allowable shear stress,some measures like as anchor piles for restricting transverse compaction distortion are required.