Research On Effect Of Dynamic Compaction On Enrockment Foundation

As an economical and effective method in the consolidation of soil, dynamic compaction is been applied more and more effectively in capital construction which has been created by L.Menard in 1969. Its working principle is to make at a given distance the heavy hammerfalls licedown to the foundation where the impacts and vibration are formed to make the powerfulstress wave, cause the variation of internal stress in soil mass and pressure of void water, etc.and achieve the improvement of foundation strength . Mnrockment ground improved by dynamic compaction is the method that developing the ground which is filled by Mnrockment with the way metioned in the former. The range of application which comes down to the enrockment ground improved by dynamic compaction is larger and larger. At the same time, theoretical and experimental researches have been done gradually. Although there are comparatively some researches on it, the design of dynamic compaction is highly empirical and qualitative because of the complicated parameter of the ground. In addition, the degree of improvement for dynamic compaction and strengthening the quality of detection is also needed to explore in depth. By now, there have been many successful practices and experiences in consolidation of the enrockment ground by dynamic compaction method, but the theory study lag the engineering practices at all times. From the above mentioned, to develop the theory and application study of the Dynamic Compaction on enrockment foundation has the extremely important theoretical value and the project application value.This paper discussed the strengthening principle for dynamic compaction at first, and then introduces the method to ascertain the deep of dynamic compaction effective reinforcement on enrockment ground detailedly on basis of typical engineering in Shenzhen. The Gray system theory then is deployed to analyze the various factors that affect the settlement of dynamic compaction, and also real on-site data is analyzed and results presented the facts that concerning to the influences all the factors imposed on accumulated settlement sequence in the order of influential power is as follows: height of hammer >energy of tamp > times of tamp> diameter of hammer > weight of hammer. An empirical formula of dynamic compaction accumulated settlement of throwing stone ground can then be presented by comparing the actual results of further real on-site dynamic compaction with simulated results derived from former data . Meanwhile, the paper analyzed the date to monitor the enrockment ground improved by dynamic compaction , then figured out the percent consolidation and settlement of the ground by the exponential curve fitting method .Finally, the paper studied testing method after dynamic compaction and combined with engineering analysis of such in-situ testing method as Rayleigh wave and plate loading test used in the enrockment ground engineering. It also summarized the technological process of enrockment ground improved by dynamic compaction based on the coherent engineering. Through such study, the heavy tamping foundation treatment technique has been supplemented and consummated or improved.