强夯技术处理饱和土地基的试验研究

Experimental Study on the Dynamic Compaction to Improve Saturated Clay

根据强夯加固饱和土地基的机理 ,依托一工程实例 ,以及强夯效果检测的实测数据 ,系统研究了饱和粘性土地基强夯后的强度特征 .在强夯检验中 ,采用了原位和室内试验测定强夯后土的强度和压缩性 ,并对试验数据进行了统计分析 .原位试验指标的随机特性采用左截尾正态分布的概率密度函数来描述 .根据结构可靠性分析原理成功地提出了地基土失效点概率的概念 ,并将其应用于强夯加固效果的综合评定 .最后 ,对强夯加固饱和土地基失败的原因进行了分析 ,并对强夯地基强度随时间的增长而增长 ,即时效性这一新的领域进行了初步探讨 .

On the basis of the mechanical theory of dynamic compaction to improve saturated clay, the strength characters of the clay improved by dynamic compaction are discussed systematically from one case history and the results of verification test. Both in situ tests and laboratory tests were used to measure properties of the soils such as the strength and compressibility improved by dynamic compaction, and the values of the tests are analyzed statistically. The indexes of field tests were represented by the normal distribution probability density function for its values to truncate it below zero. The probability of failure spots in the ground is successfully proposed based on the principle of structure reliability analysis to estimate synthetically the quality of the soft soils improved by dynamic compaction. Finally, the cause responsible for the failure in the saturated clay improved by dynamic compaction is presented, and the strength gain of dynamically compacted soils with time, called the aging effects, as a new problem is discussed primarily.