The current Federal Aviation Administration design procedures for airport concrete pavements do not directly consider top-down cracking. However, this distress has been repeatedly observed in full-scale tests conducted at FAA’s National Airport Pavement Test Facility (NAPTF) and AIRBUS in Europe. Generally, the maximum load stress related strain near the slab bottom is mostly higher than the …
LOKASI: Ruang Koleksi Umum Rak: 2
The filter cake on the tunnel face has a significant influence on project of the slurry-driven shield. During the excavation, only permeable filter cake is allowed to form because the rotating speed of cutter wheel is fast. Through the filter cake, the water of slurry will infiltrate into the soil. The water enhances the hydraulic head and the risk the failure of tunnel face. In order to determ…
The tunnel leakage in sand layer plays an important role in the evolution of the lining stresses and the ground movement. The phenomenon of internal erosion occurs when underground water leaks into the tunnel from the damaged joints or the cracks of the linings. Fines in sand are pulled off by seepage forces and transported throughout the soil matrix into the tunnel. The loss of fines due to se…