The application of rock mass rating and slope mass rating systems on rock slopes of al-Salman depression, south Iraq

Abstract EN

An empirical method using Rock Mass Rating (RMR) and Slope Mass Rating (SMR) has been applied based on field observations and measurements, and laboratory tests to estimate the strength of rock mass and to assess the stability of rock masses on slopes forming the edges of Al-Salman Depression, located 130 Km southwest of Samawa city, South of Iraq.

This procedure is beneficial for acquiring better understanding for the influence of the geological and rock strength parameters, and the mechanism of rock failure on slope stability analyses and processes of open cast mining and quarrying.

Field observations and measurements were carried out at seven sites along the edges of Al-Salman Depression, where some rock slope failures have occurred.

The seven studied sites comprise the rock slopes of the Middle Member of the Dammam Formation (Middle Eocene), which consists of alternation of white, grey and yellowish grey, dolomitic limestone, occasionally, nummulitic and chalky limestone.

Slope mass rating is calculated based on values of Rock Mass Rating and joint and slope orientations.

The calculated RMR values involve Class C of Fair Rock Mass and Class B of Good Rock Mass.

The calculated values of SMR are within Class II of Good and Stable; in most of the studied slopes, but only one site (site 4) is within Class III of Normal, Partially Stable.

The calculated results match some of the site conditions.