This paper deals with in-situ shear strength parameters of rock mass determined by conducting a set of five shear tests in the right abutment drift (Reasi end) and a set of six blocks on the left abutment drift (Katra end) of proposed bridge for Udhampur Srinagar Baramulla Rail Link (USBRL), across Anji, a seasonal tributary of Chenab River, near Reasi. The proposed Anji Bridge is 186m high and 657m long. The shear strength parameter values of cohesion (c) and friction angle (φ) were interpreted by conducting in-situ shear tests for rock to rock interface from five blocks at right abutment and six blocks at left abutment. As the rock mass was jointed and fractured with few shear zones, the shear strength parameters were evaluated only for residual values and peak value could not be differentiated, which was clear from the shear stress versus shear displacement curve. The results of in-situ testing confirmed the rock mass with almost similar shear strength parameters at both the bridge abutments.
It is proposed to construct an arc bridge for Udhampur Srinagar Baramulla Rail Link (USBRL), across Anji, a seasonal tributary of Chenab River, near Reasi district, Jammu & Kashmir, India. The proposed Anji bridge is 186m high and 657m long. The Schematic view of proposed Anji Khad Bridge is shown in Fig. 1. The Central Soil and materials Research Station (CSMRS) undertook the investigation works of determining the deformability and shear strength characteristics of rock mass required for the design of bridge foundation at Anji Khad (CSMRS 2009). This paper deals with in-situ shear strength parameters of jointed rock mass determined by conducting in-situ shear tests in both right and left abutment drifts of Anji Khad bridge.
Massive to blocky dolomite is exposed along both the banks of Anji Khad below the proposed arch foundation up to a height of 50m with wide range of colours (white, light grey, dark grey and pale brown) and different degrees of weathering (fresh, slightly and moderately) and fracturing (moderately and intensely); rolled-down boulders and chips of dolomitic limestone and limestone with silt and clay material and siliceous limestone. The strata in the area are characterized by prominent one sub-horizontal foliation joint and two sub-vertical joints. The foliation joint strikes roughly N-S and dips 200 to 300 in East direction as shown in Fig. 2. The first joint strikes roughly NE-SW and dips 800 to 850 in NW direction and the second joint strikes SE-NW and dips 600 to 700 in SW direction. A few sub-vertical random joints are also present. The strata have major three sets of discontinuities, which are continuous and persistent. At most of the places, the foliation joint and the other two joints intersect each other forming cubical structure. In weathered and fractured dolomitic limestone and limestone, the average spacing of the foliation joint is 5 to 10 cm and of the other joints is 10 to 15 cm.
