Core Recovery and RQD (Rock Quality Designation) The easiest way to characterize the amount of material recovered during rock coring is to calculate “core recovery” as the amount (i.e. length) of recovered material divided by the total length of the core run (presented as a percentage). Rock Quality Designation (RQD) is a modified core recovery … Read more
Strength and Modulus of Weathered Rock from SPT Values In the weathered rock it is difficult to drive the split sampler to the full specified depth as in soil. Hence we may estimate the strength and elastic modulus values of weathered rock by driving the spt apparatus for a fixed number of blows and find … Read more
This method of rock classification was introduced by Deer & Miller in the year 1996. Two parameters are considered while classifying rocks on this method, which are Uniaxial compressive strength Modulus of elasticity Step by Step Method to Classify Rock Based on Engineering Parameters) This method of rock classification consists of 3 steps, as given … Read more
Classification Based on Degree of Weathering of Rock Mass Rocks can be classified on the basis of its degree of wreathing. These type of rock classification gives the engineer qualitative idea of rock mass. This type of classification is generally done on site and only by a through visual inspection rocks can be classified. While … Read more
Modulus of Elasticity of Rock Modulus of elasticity of rocks depend upon several factors, such as, Type of rock Porosity Grain size Water content Value of modulus of elasticity can be determined by static or dynamic methods. Higher value of modulus of elasticity indicates good quality rock having sound composition. Typical values of modulus of … Read more
Rocks can be classified on site, on the basis of its physical appearance. By making a through visual inspection we can ascertain the engineering properties of rocks. Field classification of rocks gives us logical insight about the suitability of rocks for engineering purpose. This type of classification is known as geological or lithological classification of … Read more
Rock Classification On the basis of genesis or mode of origin, rocks are classified into following three major groups. Igneous Rocks Sedimentary Rocks Metamorphic Rocks 1. Igneous Rocks These types of rocks are formed by the solidification of molten magma in the interior of the earth. When a rock is formed by cooling and solidification … Read more
Aim To determine porosity and density of rock using saturation and buoyancy techniques as per IS-13030-1991. Apparatus Oven (capacity 105±30C) Balance (Accuracy of 0.01% of the sample weight) Non corrodible sample container Vacuum vessel for immersion of sample (capacity 0.8 kPa) Immersion bath, wire basket for determination of saturated-submerged weight) Procedure Take at least 10 … Read more
Aim To determine point load strength index of rock as per IS-8764 Equipments Point load strength test machine A 100 mm scale attached with the loading frame Pressure gauge (Capacity 25 kN or 50 kN) Depending upon the size and shape of test specimen, the point load strength index can be conducted by four different … Read more
Reference IS-10050-1981-Method for determination of slake durability index of rocks. Objective This test is done to find out the resistance offered by a rock sample to weakening and disintegration when subjected to two standard cycles of drying and wetting in a slaking fluid usually water. Apparatus used NAME OF EQUIPMENT CAPACITY LEAST COUNT/ACCURACY Balance As … Read more