In-situ Test And Study On Influence Of Surroundings Around Foundation Pit Owing To Lateral Displacement Of Soil Nailing Support

This dissertation analyses influence on surrounding soil body's deformation owing to deep excavation in detail, adopting field test method mainly and numerical analysis method. It put forward a method so that we can calculate settlement of vary depth soil body behind the slope and confirm remarkable influence area produced among the near building of the body behind the slope owing to pit excavation based on the field measurement's soil body horizontal displacement and the surface settlement. The achievement that this dissertation makes is concrete as follows:1. Soil body settlement and horizontal displacement have dependence behind the slope. It shows firstly that the earth's surface settlement after the wall is correlated with the whole horizontal displacement of wall. When the horizontal displacement distribution forms is different along the depth, by which the surface settlement and the influence area caused are different. So, estimating the settlement amount of the soil body after slopes is not merely relate to the amount of displacement of the wall and is still affected by whole horizontal displacement of the wall. Secondly, under this text experimental condition, the relation between the moving area in corresponding stratum owing to the soil body's lateral deformation and the earth's surface settlement stratum's moving area can be expressed by ration as follows: A _{surface settlement}= (0.70 0.85) A_{horizontal displacement}. We can calculate settlement of vary depth soil body behind the slope according to this ratio relation by the field test's soil body horizontal displacement.2. When confirming the influence area of around buildings owing to the foundation pit's excavation after the slope we can analyze by soil body's settlement and settlement curve's slope. Two differentiation's solution is similar. When applying different settlement criterion we confirm differentiation's criterion based on buildings' practical adapt case owing to different influence area. Confirming the influence area only based on relative foundation pit depth's ratio (b/H) is not veracious. We must consider foundation's embedment depth and settlement distributing curve's figure.3. This dissertation proposes that confirming the remarkable influence area produced among the near building of the body owing to pit excavation should consider the settlement amount of the soil body and the develop tendency of settlement at the same time. It can confirm by proportionate relationship between body settlement area A_b among the different level distance b and A_total.Under the experimental condition of this dissertation, we regard corresponding b value as the remarkable coverage of the soil body when A_b / A_total is 70%.