一間幅全面土壁の静的繰り返し載荷実験の統計的検討に基づく土壁の荷重－変形角包絡曲線の推定方法

Abstract

Based on many reports that have been already published for experiments of mud wall subjected to cyclic loading, a method to make envelope curve is proposed here by statistical studies. The walls for the examination are full-scale mud walls of about 1.8m width and all of both sides of the wall are plastered without final coat. The main observation from this statistical investigation of the database is as follows. (1) The average of maximum strength is about 15kN at 1/52rad. The average of strength reduction is about 41% of the maximum strength at 1/15rad and about 47% in 1/10rad. The average of ultimate strength of Elasto-Plastic Model is approximately 88% for the maximum strength. (2) In this data, we found a gradient of secant in a specific shear deformation angle of wall has a considerably strong correlation with the gradient in the next specific angle. (3) We suggest an estimation method of the envelope curve of the mud wall by statistical studies. After the strength of the wall in a small deformation is evaluated by using the compressive strength of wall clay, the envelope curve is predicted by a specific gradient of secant and the above correlation coefficients. Finally, the estimated envelope curve of the mud wall predicts in large deformation until 1/10rad. This envelope curve has the deteriorate state. The same procedure enables to make envelope curve in Kyoto. As a result of having estimated the envelope curve of the Kyoto mud wall, it is as follows. (4) The envelope curve of the Kyoto mud wall can be estimated by applying the correlation coefficients of the experimental data of the Kyoto mud walls. The estimated curve of the Kyoto mud wall gives a considerably good approximation of experimental curves that force deteriorates in large deformations. (5) When the envelope curve of the mud wall which have the local specification is estimated, it is enabled even to gather up more than three experimental data, but it may be estimated result more than the experimental value in large deformations. The envelope curve of the local mud wall could be more appropriate by increasing experimental results in the database. (6) The strength difference is about 40% between experimental results and the estimated results.