Influence of slaking and disintegration effect on the stability of water tunnels for hydropower
Original version
ARMS10 10th Asian Rock Mechanics Symposium The ISRM International Symposium for 2018Abstract
The manuscript presents initial results of a potential linkage between the mineral composition and structural strength in geological samples from a hydropower tunnel currently under construction. Changes in rock properties due to processes of both chemical as well as mechanical weathering are very important issues for water tunnels constructed for hydropower. Weathered and weak rock mass have strong slaking and deterioration potential if in contact with water, which may result failures in the unlined / shotcrete lined water tunnels. The slake durability of intact rock is in many cases closely linked to the mineralogy, especially on the content of weak clay minerals. When the weak rock mass is exposed to water it may lead to the degradation caused by the destruction of the intact rock structure. Such phenomenon may also aggravate swelling possibility in the rock mass if clay-bearing rocks are constituted by swelling minerals like montmorillonite (smectite). The manuscript first evaluates the mineral composition of the rocks collected from the tunnel, and then the initial laboratory assessment on the extent of slaking is presented. Further, the slaking extent is linked to long-term stability issues in tunnels caused by slaking and disintegration. Influence of slaking and disintegration effect on the stability of water tunnels for hydropower