Table 1 Comparison of two construction methods.
From: Damage and reliability analysis of double-arch tunnel without a middle pilot tunnel under blast load
Construction method | Advantages | Disadvantages |
|---|---|---|
Traditional method | (1) The excavation of subsequent tunnels has minimal impact on preceding tunnels (2) Construction techniques are well-established (3) Smaller excavation cross-section, thus less disturbance to the surrounding rock mass | (1) The construction process is more complex (2) Longer construction period (3) Higher construction costs |
Continuous arch tunnel without intermediate adit | (1) The construction process is simpler (2) Shorter construction period | (1) The absence of an intermediate adit reduces the distance between preceding and subsequent tunnel excavations, increasing mutual interference (2) The steel arch frames for subsequent tunnels are overlapped on reserved interfaces of preceding tunnels, which imposes higher requirements on the steel arch frames |
