發送短信 : Stability analysis of underground excavation

 ______    _    _    _    _     ______    _____   
|      \\ | || | || | || | ||  /_   _//  |__  //  
|  --  // | || | || | || | ||   -| ||-     / //   
|  --  \\ | \\_/ || | \\_/ ||   _| ||_    / //__  
|______//  \____//   \____//   /_____//  /_____|| 
`------`    `---`     `---`    `-----`   `-----`