Experimental Study Of Spread Foundation Uplift Characteristic On Swelling Soil

Soil anti-pulling mechanics is complex, studied not for a long time and is not as deeply investigated as soil load-bearing mechanics, domestic and overseas researches there currently is not a logical expatiation to it in theory. At present, concentrate on dealing with anti-pulling mechanics of non-cohesive soil. Since there are less influencing factors and relative definite theoretic of soil up-pulling destruction for non-cohesivesoil than for cohesive soil, the latter is few researched. However it is hardly explored in swelling soil.Swelling soil is multi-crevasse earth with swell-shrink characteristics forming in the natural geological transportation, its characteristic is that soil expands in absorption but shrinks in dehydration. In other words, cracks easily appears in dehydrated swelling soil leading to higher intensity, contrarily, hydrated swelling soil turns into disintegration and argillization so that its body-soil structure is destructed and its intensity gets lower. There is less data of anti-up-pulling test of soaking or non-soaking swelling soil and no concrete stipulation in standard. It is of great importance to research anti-pulling mechanics for the wide distribution of swelling soil in our country.In this paper, we present the load-foundation experiments of swelling soil of 500KV high voltage transmission line from Handan to Shijiazhuang. Those tests include anti-pulling destruction mechanics, up-pulling displacement, and anti-pulling bearing capacity, the change of bearing capacity with or without soaking or not condition and so on. Our main work and important results are as follows:1. Comparing with its load-bearing mechanics, anti-pulling mechanics of swelling soil is much more complicated because of it structures with multi-crevasse and distinct swell-shrink attribute, and for it is sensitive to water, and will disintegrate with the non-existent extra-pressure. Even when its water quantity reaches a certain percentage, it will be in argillization causing its cohesive strength and friction angle become much smaller. Thus there are so many influence factors of swelling soil that anti-pulling mechanics is much more complicated. In this paper, a large-scale test model was introduced as prototype test in order to reduce the influence of its dimensional effect. At the same time, we studied the anti-pulling...