Analysis of the Technical Characteristics of the Construction of Extra-long Tunnels under Complex Geological Conditions in the Event of Large-scale Water Surges and Blasting.

Abstract

2012-2022, China's investment ratio in the construction of basic transportation facilities gradually increased, the railroad and highway increased mileage of about 1.1 million kilometers; especially for the central and western regions of the continued investment in infrastructure and transportation, sichuan province as a large inland province in southwest China, "twelfth five-year plan" at the end of the total mileage of ordinary highways in the province amounted to 289,000 kilometers, the Regional development imbalance is prominent, the breadth of the road network is insufficient, the depth is obviously insufficient; ten years, the province through the reconstruction and expansion, now the province's total mileage of ordinary highway more than 390,000 kilometers, ranked first in the country, one year ahead of schedule to complete the goal of transportation out of poverty, "dense road network" aims to strengthen connectivity; do strong hubs, can improve transport efficiency! In addition, it can even promote the economic development of towns and cities, strongly guarantee the stability of economic operation, promote the level of regional coordinated development and continuously improve, but also to support the national strategic ability to continuously increase the basic ballast stone. Sichuan is surrounded by mountains on all sides, with large differences in landforms, complex and varied terrain, located in the transition zone between the first level of the three major terrain gradients of the Chinese mainland, the Tibetan Plateau and the third level of the middle and lower reaches of the Yangtze River Plain, consisting of mountainous terrain, hilly terrain, plains, basins and plateaus. As the saying goes, "the road to Shu is difficult, more difficult than the sky", in order to turn "the road to Shu is difficult" into "the road to Shu is smooth", the builders of the mountains and water bridges, and tunneling is essential to the main event. The construction of tunnels is the most important part of the project.