Showing papers on "Shear wall published in 1988"

Softened truss model theory for shear and torsion

Abstract: The softened truss model theory, which has recently been developed for shear and torsion of reinforced concrete members, is summarized in a systematic and unified manner. Eleven equations involving fourteen variables are derived from equilibrium, compatibility, and materials conditions to solve the shear problem. An additional six equations involving six more variables are required to treat the torsion problem. The theory was successfully applied to structures where shear behavior predominates, such as low-rise shearwalls, framed wall panels, deep beams, and shear transfer strengths. It also worked very well for members subjected to torsion. Efficient algorithms are proposed to solve the simultaneous equations for different types of structures. The theoretical predictions are in good agreement with the test results in all cases. The prediction includes not only the shear and torsional strengths, but also the deformations of structures throughout their post-cracking loading history.

Reinforced Concrete Fundamentals

Abstract: Introduction. Materials. Flexural Analysis and Serviceability of Beams. Design for Flexure. Shear and Torsion. Axial Load Plus Bending--Short Columns. Slender Columns. Development and Slicing of Reinforcement. Continuous Beams and One-Way Slabs. Detailing of Joints. Limit Design. Two-Way Slabs on Stiff Beams. Yield Line Theory for Slabs. Strip Method for Slab Design. Flat Plates and Flat Slabs. Interaction of Two-Way Slab Systems with Beams and Columns. Distribution of Concentrated Loads and Other Special Problems. Cantilever Retaining Wall Design. Footings. Prestressed Concrete Analysis. Composite Beams. Shear Walls. Detailing for Seismic Resistance. Appendices. Index.

Stiffness identification of a tall building during construction period using ambient tests

Abstract: Ambient response measurements were made on an eighteen-storey building at three different stages of construction to detect any changes in the frequencies, mode shapes and stiffness with construction. The first nine frequencies and corresponding mode shapes for each stage of construction are found. A comparison is made among these mode shapes and frequencies and with the mode shapes and frequencies of an analytical model incorporating beams, columns, shear walls, panels and diagonal elements. The added effects, on frequencies and mode shapes, of non-structural elements such as stairs, elevators, claddings and partition walls are studied. Using Improved Statistical Structural Identification, an attempt is made to study the stiffening effect of non-structural elements by updating the stiffness matrix of the building.

Single‐ and Double‐Sheathed Wood Shear Wall Study

Abstract: A mathematical model for the analysis of partially composite wood light‐frame shear walls loaded in plane is presented. Shear walls consisting of a stud frame with sheathing placed either on one side or both sides are investigated. Nonlinear behavior due to sheathing gaps is modeled. Nonlinear interlayer slip between the frame and sheathing is included by a developed step‐wise procedure. Experimental results are used to verify the mathematical model.

An Efficient Element for Analysis of Frames with Shear Walls

Abstract: A rectangular plane stress element (W12 element) with 12 degrees of freedom is introduced for the analysis of building frames with shear walls. The W12 element has four nodes and each node has degree of freedoms for two translation and one rotation.

Nonlinear modeling and seismic analysis of masonry shear walls

Abstract: Empirical hysteretic models are developed for masonry shear walls using the results of cyclic tests performed by different investigators on 37 single-story walls. The models account for the deteriorating nature of the response of masonry shear walls to cyclic loads, and distinguish between the hysteretic characteristics of walls with shear or flexural modes of failure. These models are used to compute the nonlinear response of single-story reinforced masonry shear walls to 16 recorded earthquake ground motions with different intensities and frequency contents. The effects of the deteriorating nature of masonry shear wall hysteretic behavior on its nonlinear seismic response characgeristics are investigated by comparing the computed responses of masonry walls and some hysteretically stable (e.g., elastoplastic) systems. The effects of the wall dominant failure mode (shear or flexure) on its response to earthquakes are also evaluated. Suggestions are made for the required strength of masonry shear walls located in regions with different seismic risks.

Stability of Shear‐Wall Structures

Abstract: A simple approximate lower bound formula is proposed for the gravity buckling loads of coupled shear‐wall structures using continuous medium assumptions. The deflected shape of the system is decomposed into those of flexural and shear‐flexure cantilevers. For the latter, an accurate approximate buckling load formula is also presented. Inserting the buckling loads of the two systems in Dunkerley's formula yields the required buckling load. The formula is compared with exact results computed by finite differences and good agreement is demonstrated.

Theory and calculation of frame structures with stiffening walls

Abstract: 1 Structural frame systems with fillers and walls 2 Frame fillers 3 Theories of wall fillers 4 Frame wall filler simulated as a storey girder 5 Wall filler for Type 3 frames 6 Stability of Type 3 wall fillers 7 Column structural systems stiffened with walls 8 Theory of frames with Type 1 wall fillers subjected to horizontal loads 9 Theoretical analysis of frames with Type 2 wall fillers subjected to horizontal loading 10 Calculation of multistorey frames with Type 3 wall fillers subjected to horizontal loads 11 Theory of column systems with bar members 12 Theory of frames with filling panels subjected to vertical loads 13 Theory of frames with wall fillers assuming settlement of foundations 14 Solution of stability problems of hinged frames 15 Consideration of volume change in the calculation of frames with walls or wall fillers 16 Consideration of physical and geometrical nonlinearities in the theory of calculation of frames with fillers and walls 17 Numerical solution of frame structures with wall and bar fillers References

Analytical modelling of large panel coupled walls for seismic loading

Abstract: Modelling techniques for analysis of large panel wall systems with coupling beams, subjected to earthquake loading, are described. The models, implemented in an existing general purpose computer program, are evaluated through a series of analyses involving comparisons with other reported analytical results and with limited available experimental data. The sensitivity of analytical results to assumed structural parameters is highlighted. Key words: beams, earthquake engineering, finite element method, joints, precast concrete, seismic, structural analysis, structural walls.

Structural connection system

Abstract: STRUCTURAL CONNECTION SYSTEM A structural connection system for resisting uplift loads on the shear walls for each level of a wood framed structure includes anchors for each level. The system, employed at least at the lateral ends of the shear walls, compressively restrains the shear walls against upward movement. The anchors, which are vertically aligned, are coupled to one another through tie rods. A tie rod connects the anchor for the bottom floor to a foundation anchor embedded in the foundation. The anchors and tie rods are positioned between pairs of closely spaced vertical framing elements, such as studs. Uplift loads for each level are transferred to the foundation through the connection system. This eliminates any accumulation of uplift loads from level to level.

Structural Behavior of Prefabricated Shear Walls

Abstract: In precast large-panel multistory buildings, prefabricated jointed panels form the shear wall to carry the lateral loads due to wind, etc. The in situ vertical and horizontal joints form slip surfaces and the interaction between the precast panels are provided by shearing action at the joints. In this paper, plane stress and interfacial finite elements have been used to represent the precast wall panels and the in situ joints. The effect of the in situ joint properties has been studied in depth as regards the overall flexibility and stresses in the prefabricated shear wall. It was observed that very stiff vertical joints between the panels makes the shear wall stiff like monolithic cantilever walls, whereas loosely jointed prefabricated walls are more flexible. It was also observed that the effect of horizontal joints at the floor levels is only marginal under normal circumstances. Failure load of a typical prefabricated shear wall has been determined from the nonlinear analysis of the wall assembly assum...

The Whittier Narrows, California Earthquake of October 1, 1987—Ticor Title Insurance Building Damage

Abstract: The Ticor Title Insurance Building was a recently designed building that was significantly damaged by the recent October 1, 1987 Whittier Narrows Earthquake. The building experienced shear wall failures, floor and roof diaphragm failures, as well as failures of spandrel panel anchorages. The damage is chronicled by photographs in this article. This building, which is constructed chiefly of precast elements, shows the importance of tying together adequately different parts of a building. Special attention to building configuration, building deflection, connection and anchorage details is recommended.

Ultimate load capacity of square shear plates with circular perforations

Abstract: Working platforms and support caissons of offshore steel structures are often designed with plate boxes or plate girders. The important shear walls or shear webs must often be perforated to allow utilities, etc., to pass through. The failure mode of these large perforated shear panels is typically shear buckling, usually in the plastic range. The paperpresents results of a finite element buckling analysis with inelastic material behaviour and gives general guidelines for the ultimate capacity design of perforated shear plates. The parameters affecting the ultimate capacity of square plates with circular perforations under uniform shear stress were investigated using the incremental structural analysis program NISA83. Nonlinearities in material properties and geometry were taken into account in the calculation of ultimate capacities of each perforated shear plate.The parameters investigated in the study were hole size for a concentric hole and hole location for a constant hole size. Only single unreinforce...

FEM Analysis of RC Shear Walls and its Application to a Theoretical Model

Abstract: In order to calculate the shear capacity of a reinforced concrete (RC) shear wall, some models based on the theory of limit analysis (called “Macro model”) are proposed. These models contains many assumptions which need to be certified, and FEM analysis is considered to be a useful method to examine these assumptions. So, in this study, a nonlinear FEM program to analyze RC shear walls was developed, and the correctness of the macro models was examined by using the FEM analysis.

A Two Stage Identification Approach in Updating the Analytical Model of Buildings

Abstract: Ambient response measurements were made on an eighteen-story building at three different stages of construction to detect any changes in the frequencies, mode shapes, and stiffness with construction. The first nine frequencies and corresponding mode shapes, for each stage of construction, are found. A comparison is made among these mode shapes and frequencies and with the mode shapes and frequencies of an analytical model incorporating beams, columns, shear walls, panels and diagonal elements. The added effects, on frequencies and mode shapes, of nonstructural elements such as stairs, elevators, claddings, and partition walls are studied. Using Improved Statistical Structural Identification, an attempt is made to study the stiffening effect of non-structural elements by updating the stiffness matrix of the building.