tailieunhanh - Underground works in soils and soft rock tunnnelling

Nhu cầu gia tăng về giao thông hiện đại, mạng lưới điện đã tăng nhu cầu về một nhiều hơn mở rộng và xây dựng sử dụng không gian ngầm. Kết quả là, nhiều dự án ngầm đã được hoàn tất trong một loạt các điều kiện mặt bằng, bao gồm cả đất ít nước và đá mềm. Công nghệ tiến bộ nhưng cũng đã làm tăng những thách thức mới như nhiều của các dự án phải được hoàn thành trong điều kiện khó khăn, với sự nghiêm ngặt hạn chế môi trường, đặc biệt là ở khu vực thành thị,. | UNDERGROUND WORKS IN SOILS AND SOFT ROCK TUNNELING Eric Leca1 Yann Leblais2 and Karl Kuhnhenn3 ABSTRACT Growing needs for modern transportation and utility networks have increased the demand for a more extensive and elaborate use of underground space. As a result more underground projects have to be completed in a variety of ground conditions including weak water bearing soils and soft rocks. Significant technological advances have rendered these projects possible but have also given rise to new challenges as many of these projects have to be completed in difficult conditions with very strict environmental constraints particularly in urban areas where the potential impact of tunneling on existing structures is a major concern. This report addresses the main aspects of tunneling and underground works performed in soils and soft rocks. A summary is presented of the main features related to construction techniques ground investigations design methods and instrumentation and monitoring practices as well as of some of the more recent advances in these fields. Significant progress has been made in the area of soft ground tunneling over the past thirty years partly because of advances in computer technologies. The scope of increasing difficult project conditions to be addressed requires that the best use be made of these technologies as well as of lessons gained from past experience and current observational records. INTRODUCTION Growing needs for modern transportation and utility networks have given rise to an increased demand for a more extensive and elaborate use of underground space. Some of these projects are related to urban development which requires the construction of more metro systems underground water mains gas pipes telecommunication and electric power networks as well as underground parking facilities. Other applications of underground construction include the crossing of natural barriers such as rivers and mountains that are found across the alignment .