This issue consists of four papers. The first paper, �Evaluation of Amplification Factor for Open Ground Storey RC Structures with Infill Openings in Upper Storeys�, by Pooja A Kuntanavar and Hemant Sonawadekar, studies the amplification effect of multistorey structures with opening in infill walls in upper storey. The authors have analyzed the seismic response of fully infilled and open ground storey models and also having different percentages of wall openings. The analysis considers with and without soil interaction effects. The study considers micro modeling (also called finite element method) and macro modeling (commonly called diagonal struct method). The macro modelling could be one, two or three diagonal struct considerations. Here three diagonal struts have been taken. Four different cases of infill openings have been investigated. For comparison of results, bare frame is also analyzed. The study uses ETABS2009 software. Natural period, displacement and drift for bare frame will be higher as compared to infilled wall frames. Further, open ground storey structure is also flexible with high natural period. Base shear decreases when openings in walls increase. Storey drift decreases with increase in elevation of the buildings for both fixed base and flexible base and for different opening percentage in infill. Further, consideration of soil effects in analysis enhances the flexibility of the structure, thus reducing the base shear. Amplification factor decreases with increase in opening percentage of infills.

The second paper, �An Experimental Investigation on the Mechanical Properties of Glass Fiber Reinforced Concrete�, by K Vasu, P Murahari Krishna, J Siva Rupa, A Vinodh Kumar and N Janardhan, investigates the properties of glass fiber. The study is undertaken in order to find an alternative construction material. The study aims at reducing the impact of waste material on environment and also find out the percentge use of admixtures feasible for construction. Concrete has good strength in compression but is very low in tensile strength. Thus, under low loads, it starts cracking. To arrest the cracking, various items are tried and glass fiber is one of them. Fiber glass is a lightweight, very strong and robust material. The study uses type E glass with 50 mm fiber length and 0.1 mm diameter. The aspect ratio is 500. The concrete mix is prepared using cement, aggregate, sand, water, fiber glass in different proportions and admixtures. After casting of concrete specimen tests such as slump, compression, tension, ultrasonic pulse velocity, impact resistance and rebound hammer were done on various samples. The results conclude that 0.3% of glass fiber by volume can be taken as optimum dosage which could give higher compressive strength of concrete. The increase in split tensile strength at 28 days of 0.35 fiber volume to the concrete is taken as optimum. The nondestructive tests like rebound hammer test and ultrapulse velocity test indicate less value for compressive strength when fiber glass is added. The impact energy tests gave a good result in fiber glass concrete.

The third paper, �An Experimental and Analytical Investigation of Mixed Mode Fracture on RCC Beams�, by Sushrut Pawar and Kiran M Malipatil, investigates the fracture pattern of RCC beams under loading. It is believed that fracture mechanics be considered in the design of important structures like bridges, off shore oil rigs, dams, etc. The study chose four RCC beams with creation of notches at different locations in the beams and studied its fracture pattern both analytically and experimentally. The study chose linear elastic fracture mechanics principles to determine the effect of mixed mode fracture. The fracture patterns are divided into three different modes, viz., crack opening mode, in-plane shearing mode and anti-plane shearing mode. Depending on the cracks observed during tests, a fracture mode is defined. The concrete beam is cast using M20 concrete and with design of mix following IS 10262(1982). The mix proportion arrived at for the study was 1:1.54:2.53. Reinforcement in the test specimens was also provided. Three-point loading for bending test was carried out in a universal testing machine. The loads and deflections were measured and cracks observed. For the analytical study, ANSYS16.0 software is used to determine the effect of mixed mode fracture on reinforced concrete beam with notches at various locations along the span of the beam. A beam with a notch created at the bottom face of beam at a marked length called critical beam is considered for comparison as the cracks will appear in the center as well as at this notch point. Any beam with notch provided at greater length than critical beam will experience only cracking at center. If the notch is provided at length less than the critical beam, it will experience mixed mode fracture, i.e., cracking will appear either at notch tip or both at notch tip and center of the beam. It is also observed that stiffness of the beam specimen will decrease with increase in the depth of cracks and loading.

The last paper, �A Comparative Study of Finite Element Formulation and Numerical Experiment for the Large Deflections of Compound Tapered Cantilever Columns�, by K Durga Rao, N V Swamy Naidu and G Venkateswara Rao, studies the post-buckling behavior of tapered column. The cantilever usually has large deflection at the end. The authors have chosen a compound tapered cantilever having materials of two different Young�s modulus. Galerkin finite element formulation is used to obtain the ratio of post-buckling to buckling loads. As results on such columns are not available for comparison, the obtained results in the study are compared with results obtained on uniform column. The compound tapered columns are used in various structural members, and thus its study draws importance. To solve the problem, Galerkin finite element formulation is used. The final matrix equilibrium equation containing global stiffness and geometric stiffness matrices is arrived at. The large deflection equation has Eigenvalues, i.e., large deflection buckling load parameters and Eigenvectors, i.e., normalized physical degree of freedom in axial direction of the buckled compound tapered column. The model uses concentrated axial compressive load at the free end and in another case, uniformly distributed load along the axis. It is claimed that Galerkin finite element method could be successfully applied to study the post-buckling behavior of compound tapered column.