| Dynamic consolidation is initiated in Mcnard Technical Company. French. 1969. Its working principle is to make at a given distance the heavy hammer falls free down to the foundation where the impacts and vibration are formed to make the powerful stress wave, cause the variation of internal stress in soil mass and pressure of void water, etc. and achieve the improvement of foundation strength. This method has the merits of remarkable effect for strengthening, simple equipment for construction, fast construction and less construction cost, etc. so it has been widely used. At present, most of the studies on this Dynamic Consolidation technique at home and abroad are mainly centralized for use of great energy level-heavy tamping technique and saturated soft soil complex foundation while for less use of puddingstone soil, pebble soil, high filling foundation in the mountain area, so a further study in this aspects is necessary.This paper has gone deeply into study on the heavy Tamping-strengtherung principle, applicable range, great energy level- heavy tamping technique, mechanics of uneven settlement of heavy tamping-dynamic consolidation foundation and test and check of heavy tamping-strengthening foundation on basis of comprehending the recent development and study of dynamic consolidation technique in the literature of science and technology at home and abroad in combination with the living example of foundation-heavy tamped in landing area at Mianyang Nanjiao Air Port and presented the technical parameters for strengthening of foundation highly filled with pebble soil in mountain area, lower-energy tamping-compacting density for improvement of high-filled foundation, the total settlement reduction of foundation, settlement control principle; in order to accelerate the consolidated and compacted density in the filling layers and reduce the pre-compacting strengthening time presented the heavy tampering -compacting methods. In this way the final control settlement time has been achieved largely in the filling layers. The empirical formula for the effective strengthening depth and impact depth under the single impacting capacity in heavy lamping-strengthening of pebble-soil foundation has been presented on basis of the study of outcome which the dynamic stress under heavy tamping and impacting attenuates with depth and index.Through such study, the heavy tamping foundation treatment technique has been supplemented and consummated or perfected. |
