A large settlement and tilting of detached house have been often observed due to ground liquefaction. In order to reduce the damage of the detached house, we have to predict the amount of deformation precisely. Finite element analyses with comprehensive constitutive models have been widely used for this purpose. However, quite a few material parameters in the constitutive model should be determined before the analysis. That process sometimes takes a long time and requires a high cost. In order to solve these problems, the authors have proposed a new numerical scheme based on the Lagrangian mesh free particle method with a very simple constitutive model. Model shaking table tests, validation analyses of liquefaction damage at Urayasu city during the 2011 off the Pacific coast of Tohoku Earthquake and prediction analyses of virtual ground model were also carried out. Based on a series of analysis, it was confirmed that the performance of the proposed method was very promising. The following shows the summary in present paper.
1) In chapter 2, conventional analytical and numerical methods are outlined, such as Building Standards Law, guideline and finite element analysis. Building Standards Law is found that we are able to get the bearing capacity of non-liquefied ground without consideration of ground liquefaction. The guideline is found to be able to obtain the possibility of ground liquefaction. However, it does not predict settlement or tilting of detached house. The finite element analysis with a comprehensive constitutive model can predict the settlement or tilting of detached house by ground liquefaction. However, limited number of engineers can handle those programs. Furthermore the standard penetration test is usually necessary to determine constitutive model parameters and its process is expensive for detached house owners.
2) In chapter 3, a new numerical scheme based on the Lagrangian mesh free particle method with a very simple constitutive model is summarized. In new numerical scheme, the Smoothed Particle Hydrodynamics (SPH) method capable of simulating large deformation is used to discretize the numerical area concerned in space. Furthermore, it is emphasized that the simple constitutive model needs a small number of mechanical parameters.
3) In chapter 4, model shaking tests are carried out to capture the localized deformation pattern of the ground next to the detached house during liquefaction. Then, we try to reproduce the localized deformation of the ground by using the proposed SPH scheme. The proposed numerical scheme is found to succeed in reproducing the localized settlement pattern of the model detached house quantitatively.
4) In chapter 5, a detached house severely damaged during the 2011 off the Pacific coast of Tohoku Earthquake is also targeted for the verification of the performance of the proposed SPH scheme. The proposed SPH scheme is found to reproduce a large settlement of a real detached house observed qualitatively.
5) Finally, in chapter 6, we try to predict the settlement of a detached house on the virtual ground by liquefaction using the proposed SPH scheme. Based on the virtual ground model simulation using proposed SPH scheme, it is found that we are able to predict the liquefaction damage level of the detached house. Furthermore it is confirmed that settlement of detached house is affected by Dcy and H1 from results of previous liquefaction judgment and proposed method.
