国家自然科学基金项目51005068,中央高校基本科研业务专项资金项目 2682013CX030和高速铁路基础研究联合基金重点项目U1234208资助;Supported by National Natural Science Foundation of China No.51005068,Fundamental Research Fund for the Central Universities No.2682013CX030 and Fundamental Joint Research Fund for the High Speed Railway of China No.U1234208