| Summary: | 碩士 === 中華大學 === 土木與工程資訊學系碩士班 === 95 === Practically, all retaining walls may rotate under working conditions. This phase will raises the redistribution of earth pressure acting on the retaining wall. The method for estimating the mobilized shear strength of backfill behind the retaining wall and the earth pressure redistribution at any wall movement plays an essential role in the “earth pressure filed” of soil mechanics. Therefore, this paper studies 25 sets of tests (five relative densities of specimens × five initial stress states) for analyzing the lateral extension behaviors of saturated Ottawa sand, in order to predict the redistribution of earth pressure for different wall movement.
It is found that the effective mobilized friction angle φ’m is increase with the increasing of radial strain εr . The effective radial stress σ’r is decrease quickly with the development of radial strain. The relationship between σ’r and εr can be simulated by using the formula of hyperbola. The radial strain of specimen occurring at active state εrp can be determined with (q’)max method. The values of εrp range from -1.18% to -2.99% for 25 sets of tests. We can use the magnitudes of εrp to calculate the allowable displacement of retaining wall practically.
Then, the hyperbola model of σ’r - εr relationship were suggested to predict the redistribution of earth pressure acting on a retaining wall. Thus, we can employed the model to solve the thrust F and the point of the thrust on retaining wall h/H ( h: the distance of F from retaining wall base, H : the high of retaining wall) by AutoCAD soft ware. It is found that φ’m behavior inversely with the changes of F and h/H .
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