Search

This work focuses on integrated stability assessment of rocky tunnel slopes along a planned railway, namely, the Dujiangyan City to Siguniang Mountain Railway (DS Railway), which is an important transportation corridor in Southwest China. Investigating the stability of slopes at the entrances and exits of tunnels represents the first step of railway construction. Based on detailed geological engineering studies, the stability of 32 tunnel slopes was measured and evaluated by means of the slope mass rating (SMR), Chinese slope mass rating (CSMR) and Chinese continuous slope mass rating (CCSMR) systems. Moreover, a kinematic analysis technique was also employed to identify the potential failure modes of the jointed rock masses in tunnel slopes. The results reveal that the CSMR, by considering the slope height and discontinuity condition coefficient, can more robustly assess the slope stability than the SMR. Similarly, the CCSMR, which is based on continuous functions and can identify potentially dangerous slopes that should be reinforced, can reduce subjectivity. Many slopes deemed unstable and completely unstable by the CSMR and CCSMR are located on the banks of the river from Longchi to Longtan and from Xindianzi to Siguniang Mountain. The potential failure modes of the 32 slopes determined by kinematic analysis are basically consistent with the results obtained by the slope mass classification systems. These research results pave the way for stability assessment and intervention decision-making during the construction of the DS Railway.

Study on the weathering characteristics of Niche of Sakyamuni Entering Nirvana at Dazu Rock Carvings is the first step of scientific conservation. Based on the in-depth investigation on the weathering characteristics of Niche of Sakyamuni Entering Nirvana, the weathering degree was measured and evaluated by means of the in-situ non-destructive surface hardness test and ultrasonic test. The results reveal that the weathering types of Niche of Sakyamuni Entering Nirvana consist of granular disintegration, salt efflorescence, scaling, blistering, cracking, missing parts, biological colonization, and water seepage. The weathering degree of the head and foot of the statues are higher than that of the chest and abdomen in the horizontal direction, and the weathering degree of the upper parts of the statues and the ground area are higher than that between them in the vertical direction. The results of surface hardness and ultrasonic velocity are in close accordance with the weathering degree of the statues. Sedimentary and structural characteristics of sandstone lay a material foundation for various weathering characteristics and degree. The research results pave the way for condition assessment, intervention decision-making, and preventative conservation of the studied statues.