The large terrain undulations and strong regional geological structures are the typical characteristics along the Sichuan-Tibet Railway. The high ground stress problem in tunnel construction is extremely complex. especially the rockburst problem in deep-lying and hard rock tunnels. which restricts route selection schemes and becomes a major difficult problem of construction. https://www.ealisboa.com/flash-sale-Santa-Cruz-Surfboard-Recycled-Cotton-great-price/