65.9%桥隧比+多处重大地质风险段！这条高速解锁“地质迷宫”，破译高原筑路密码

Core Viewpoint - The construction of the Kangding (Kang) - Xinduqiao (Xin) Expressway faces significant geological challenges, including frozen ground, rock piles, and water-rich fault zones, which complicate the tunneling process [1][3]. Group 1: Geological Challenges - The Kangding Tunnel's surrounding rock is primarily medium-weathered granite, characterized by a fragmented structure and poor integrity, leading to a high risk of collapse during excavation [1]. - The Gongbuka Tunnel features heavily weathered granite with frequent geological changes and a high risk of collapse due to continuous groundwater erosion [1]. - The inflow of groundwater at the tunnel entrance can reach a peak of 140 cubic meters per hour, significantly compromising the stability of the surrounding rock [1]. Group 2: Construction Techniques - The project team employs a series of scientific and effective technical solutions, including the three-step method and principles of "advanced management, short advance, strong support, and frequent measurement" to ensure safety [3]. - Dynamic management and design are emphasized, with strict adherence to advanced horizontal drilling and geological survey methods to monitor the surrounding rock conditions [3]. - As of now, both the Kangding and Gongbuka tunnels have successfully navigated two major geological risk sections, with water inflow controlled within 70% of the design value [3]. Group 3: Project Significance - The Kangxin Expressway spans approximately 80 kilometers, with a bridge-tunnel ratio of 65.9%, enhancing transportation links between the Kangba region and the Chengdu Plain [3]. - The project is expected to provide robust support for highland railway construction and significantly boost the economic, social, and cultural development along the route [3].