Study On The Weak Ground Treatment With Dynamic Compaction

Dynamic compaction is a kind of deep compaction, it is a kind of method that tens tons of heavy hammers from tens of metres to consolidate soil. This kind of method develops on heavy hammer, but the mechanism of dynamic compaction is different from it, it is a new method of ground treatment. Dynamic compaction consolidate weak foundation develops very rapid in recent years, its application is very broad, not only extensive to be used in sandy soil and crushed stone, also applying extensively in fill, saturation silt and silty clay consolidated. Nowadays, dynamic compaction is extensive applied in many areas, such as industrial and civil building, storehouse, oil tank, highway and railway bed, airplane runway, pier and so on. In last few years, dynamic compaction has gotten relatively extensive application in Shandong area, and accumulated a lot of valuable experiences, but does not systematic summary and exposition. In actual project, the dynamic compaction parameter often get through tamping, it has wasted plenty of times in this way. The purpose of this paper is to summary the consolidating mechanism, the efficient consolidating depth, the chosen of technical parameter and the detection of consolidating effect of treating some kinds of Shandong area foundation soils, on the research foundation of forefathers combining with project practice, and reach related conclusion in order to guide in the future similar project construction. This paper divides into 7 parts totally: parti: the research present situation of weak foundation treating with dynamic compaction, in this part discussing dynamic compaction consolidate mechanism, the calculation and analysis of efficient consolidating depth and detection of consolidating effect. Part2: the influences factor analysis of dynamic compaction consolidating depth, in this part discussing the influencing factor of dynamic compaction consolidating depth and the influences of each factor to consolidating depth. Part3: dynamic compaction treating collapsibility loess foundation and the appraisement of consolidate effect. Part4: dynamic compaction treating fill foundation and the appraisement of consolidate effect. Part5: dynamic compaction treating soft organic clay foundation (compound foundation technology) and the appraisement of consolidate effect. Part6: dynamic compaction treating Yellow River alluvial foundation and the appraisement of consolidate effect. Part7: conclusions.In the few years, the author of this paper has made a lot of contrasting test in specific project practice, it includes the technical parameter, the method of detection and the contrasting of the efficient consolidate depth. These contrasts are completed through thein-site experiments, such as load test, standard penetration test, cone penetration test, dynamic penetration test, vane shear test, the hole force experiment of hydraulic pressure, ground acceleration experiment and earth worktest and etc, and gotten the plenty of indoor and on-the-site test information, gotten a lot of experience formulas through information arranging and analysising, for example the experience formula between the bear capacity and tamping energy. Along with the development of the technology of engineering geophysical prospecting, the author emphasizes the application of engineering geophysical prospecting in detection, and establishes the experience formula between Rui-lei wave and SPT number, the experience formula between Rui-lei wave and bear capacity, so not only can solve the problem of high cost and big area detection, at the same time, have also embodied the characteristic of combining with point and surface, fast and efficiency.There are many kinds of methods to calculate the efficient consolidating depth, the methods can divide into 3 kinds: experience calculation method, easier theoretical analysis method as well as value analysis methods, no matter which method or attempting to concern as far as all influencing factors, but making effort to avoid them into calculation formula, or suming up only...