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Dams are considered to be very important structures as they play an important role in the economic and social development of the area in which it is being constructed as well as utilized for hydropower generation. The concrete gravity dam is a solid structure that retains its stability against the design loads through its self-weight alone. The dam considered in this study is a structure of the Indirasagar polavaram gravity dam which is located in the village called Ramayyapeta comes under the West Godavari District, Andhra Pradesh. In this study, the finite element (FE) method is employed to numerically analyze the 2-D concrete gravity dam. The main objective of this study is to perform a linear FE analysis of the Indirasagar Polavaram gravity dam by varying the upstream hydrostatic pressure with constant downstream tailwater pressure. In the static analysis parameters like displacements, stresses and strains are assessed at each node, and their corresponding distributions are noticed. Subsequently, in the dynamic analysis approach, only free vibration analysis (Modal analysis) is done by considering only the dam's weight, the first five-mode shapes and their respective natural frequencies are extracted using ANSYS. The linear material behavior of the dam is modeled using the quadrilateral 4 node PLANE182 elements and the hydrostatic pressure is applied as triangular distribution. From the numerical analysis, it is concluded that the maximum tensile stresses are accumulated at the heel portion of the dam for cases 1 to 4, whereas it is observed distributed along the dam base for the rest of the cases. The lateral displacement and strain are observed maximum for case 1. The First mode's natural frequency of 5.81 Hz is ascertained and the maximum frequency and displacement are produced under the fifth mode.

The objective of this study is to ensure the convincing use and perfect positioning of connecting beams in between twin tower structure subjected to lateral loads. For this, a three dimensional analysis was performed for the twin towers considered without associating connecting beams and in-contrast introducing connecting beams between the two towers at different floor levels. Accordingly, eight alternatives were investigated including the one without connecting beams subjected to wind and earthquake. The wind analysis including P-Δ effect with a basic wind speed of 50 m/sec and earthquake analysis in Zone II were performed for both static and dynamic conditions. The structure considered for investigation is consisting of four residential units in each floor, with dimensions 20 m × 40 m × 54 m. The study reveals that the ‘lateral sway’ at the top of structure against wind is within the permissible limit only in case of all floors joined with connecting beams. Similarly, the ‘storey drift’ is also satisfied as per the code requirements against earthquake. Hence, it is recommended that all the tall structures proposed should be investigated for both wind and earthquake. The isolated towers can be joined with connecting beams as appropriate in order to satisfy the serviceability criteria, i.e. lateral sway and storey drift of the current codes of practice.

Lateral load is believed to be acted at the centre of mass (CM) of elevated water tank whenever ground motion takes place. Lateral load induces axial force and horizontal shear force in all the columns and vertical shear force in all the braces of the tank staging which are associated with rigid link mechanism between CM and top nodal points of the staging frame. These forces in turn develop column moment and beam moments. Lateral load analysis and staging stiffness of elevated water tanks were found by earlier investigators through analytical methods of those having approximations. The present study aims at proposing a more realistic and simple analytical method to determine stiffness and member force owing to lateral load for any given configuration of elevated tank. The nodal displacements obtained from the proposed method were in line with existing methods. Furthermore, this study attempts to carry detailed analysis of tank staging configuration which consists of columns arranged in two concentric circles. The results of the lateral load analysis show that size of the radial beam has significant influence on the responses of the tank staging.

The technology of prestressing steel structures is relatively an old frontier in the field of structural engineering. In spite of having many advantages over prestressed concrete, prestressed steel has not been popular in academics as well as in industry. This paper is an attempt to study the variation of Load carrying capacity for same Force Factor (FF), same Eccentricity Ratio (ER), same span and same cross-section strengthened in compression and tension.ISWB600@145 was considered for study for a span of 8m to 16m. Four types of cross-sections are considered for comparison, namely 1) I-section, 2) I-section laterally strengthened in compression and tension by welding four angle sections, 3) I-section laterally strengthened in compression alone by welding two angle sections, 4) compound girder formed by welding a plate to the top flange of an I-section. A straight tendon configuration over the whole span is considered for study. The non-dimensional design parameters like FF and ER were considered as 0.4 and 0.5 respectively.The % increase in the load carrying capacity for each case was calculated with respect to the beam without prestressing. It has been observed that welding a plate to the top flange of an I-section can increase the load carrying capacity of the I-section up to 80% when prestressed. In other words, the material of the cross-section is effectively utilized when an unsymmetrical I-section is prestressed.

The economy of a prestressed steel beam can be realized only when relevant parameters of optimum magnitude are chosen. The present work aims at finding out the optimum dimensions of a simply supported, laterally unsupported, prestressed steel I-beam for a given span and load carrying capacity. The span of the beam was limited to 12 m while the load carrying capacity was limited to 100 kN/m for this study. A straight tendon configuration over the whole span is considered and the losses occurring in the tendon are neglected. The safety of various sets of dimensions ranging from the minimum dimensions of I-section in IS-Hand Book-1 to their maximum dimensions for different pre-stressing forces and eccentricities are checked. The set with minimum cross sectional area is chosen. Iterative calculations involved in analysis were performed with the help of a ‘C’ program developed by the authors in Turbo ‘C’ Environment. It was observed that the ratio of top fiber stress at working loads to the permissible stress is more than 0.9 for all the spans for the finalized cross-sections. This means that the cross-section is being effectively utilized. For a given load carrying capacity and span, eccentricity to depth ratio has to be in between 0.45 to 0.7 for optimum utilization of the available cross section. It is also observed that the maximum pre-stressing force equal to 0.25 times the permissible bending compressive stress can be applied.