Structural load

Abstract: Minimum Design Loads for Buildings and Other Structures provides requirements for general structural design and includes means for determining dead, live, soil, flood, wind, snow, rain, atmospheric ice, and earthquake loads, as well as their combinations, which are suitable for inclusion in building codes and other documents. This Standard, a revision of ASCE/SEI 7-05, offers a complete update and reorganization of the wind load provisions, expanding them from one chapter into six. The Standard contains new ultimate event wind maps with corresponding reductions in load factors, so that the loads are not affected, and updates the seismic loads with new risk-targeted seismic maps. The snow, live, and atmospheric icing provisions are updated as well. In addition, the Standard includes a detailed Commentary with explanatory and supplementary information designed to assist building code committees and regulatory authorities. Standard ASCE/SEI 7 is an integral part of building codes in the United States. Many of the load provisions are substantially adopted by reference in the International Building Code and the NFPA 5000 Building Construction and Safety Code. Structural engineers, architects, and those engaged in preparing and administering local building codes will find this Standard an essential reference in their practice. Note: New orders are fulfilled from the second printing, which incorporates the errata to the first printing.

Abstract: This review article provides an overview of the problems pertaining to structural dynamics with bolted joints. These problems are complex in nature because every joint involves different sources of uncertainty and non-smooth non-linear characteristics. For example, the contact forces are not ideally plane due to manufacturing tolerances of contact surfaces. Furthermore, the initial forces will be redistributed non-uniformly in the presence of lateral loads. This is in addition to the prying loading, which is non-linear tension in the bolt and non-linear compression in the joint. Under environmental dynamic loading, the joint preload experiences some relaxation that results in time variation of the structure's dynamic properties. Most of the reported studies focused on the energy dissipation of bolted joints, linear and non-linear identification of the dynamic properties of the joints, parameter uncertainties and relaxation, and active control of the joint preload. Design issues of fully and partially restrained joints, sensitivity analysis to variations of joint parameters, and fatigue prediction for metallic and composite joints will be discussed.

Abstract: (NOTE: Most chapters include Questions and Practice Problems, Summary, and Comprehensive Questions and Practice Problems.) I. GENERAL PRINCIPLES. 1. Foundations in Civil Engineering. The Emergence of Modern Foundation Engineering. The Foundation Engineer. Uncertainties. Building Codes. Classification of Foundations. 2. Performance Requirements. Design Loads. Strength Requirements. Serviceability Requirements. Constructibility Requirements. Economic Requirements. 3. Soil Mechanics. Soil Composition. Soil Classification. Groundwater. Stress. Compressibility and Settlement. Strength. 4. Site Exploration and Characterization. Site Exploration. Laboratory Testing. In-Situ Testing. Synthesis of Field and Laboratory Data. Economics. II. SHALLOW FOUNDATION ANALYSIS AND DESIGN. 5. Shallow Foundations. Spread Footings. Mats. Bearing Pressure. 6. Shallow Foundations-Bearing Capacity. Bearing Capacity Failures. Bearing Capacity Analyses in Soil-General Shear Case. Groundwater Effects. Allowable Bearing Capacity. Selection of Soil Strength Parameters. Bearing Capacity Analyses-Local and Punching Shear Cases. Bearing Capacity on Layered Soils. Accuracy of Bearing Capacity Analyses. Bearing Spreadsheet. 7. Shallow Foundations-Settlement. Design Requirements. Overview of Settlement Analysis Methods. Induced Stresses beneath Shallow Foundations. Settlement Analyses Based on Laboratory Tests. Settlement Spreadsheet. Settlement Analyses Based on In-Situ Tests. Schmertmann Spreadsheet. Settlement of Foundations of Stratified Soils. Differential Settlement. Rate of Settlement. Accuracy of Settlement Predictions. 8. Spread Footings-Geotechnical Design. Design for Concentric Downward Loads. Design for Eccentric or Moment Loads. Design for Shear Loads. Design for Wind or Seismic Loads. Lightly-Loaded Footings. Footings on or near Slopes. Footings on Frozen Soils. Footings on Soils Prone to Scour. Footings on Rock. 9. Spread Footings-Structural Design. Selection of Materials. Basis for Design Methods. Design Loads. Minimum Cover Requirements and Standard Dimensions. Square Footings. Continuous Footings. Rectangular Footings. Combined Footings. Lightly-Loaded Footings. Connections with the Superstructure. 10. Mats. Rigid Methods. Nonrigid Methods. Determining the Coefficient of Subgrade Reaction. Structural Design. Settlement. Bearing Capacity. III. DEEP FOUNDATION ANALYSIS AND DESIGN. 11. Deep Foundations. Types of Deep Foundations and Definitions. Load Transfer. Piles. Drilled Shafts. Caissons. Mandrel-Driven Thin-Shells Filled with Concrete. Auger-Cast Piles. Pressure-Injected Footings. Pile-Supported and Pile-Enhanced Mats. Anchors. 12. Deep Foundations-Structural Integrity. Design Philosophy. Loads and Stresses. Piles. Drilled Shafts. Caps. Grade Beams. 13. Deep Foundations-Axial Load Capacity Based on Static Load Tests. Load Transfer. Conventional Load Tests. Interpretation of Test Results. Mobilization of Soil Resistance. Instrumented Load Tests. Osterberg Load Tests. When and Where to Use Full-Scale Load Tests. 14. Deep Foundations-Axial Load Capacity Based on Analytical Methods. Changes in Soil during Construction. Toe Bearing. Side Friction. Upward Load Capacity. Analyses Based on CPT Results. Group Effects. Settlement. 15. Deep Foundations-Axial Load Capacity Based on Dynamic Methods. Pile-Driving Formulas. Wave Equation Analyses. High-Strain Dynamic Testing. Low-Strain Dynamic Testing. Conclusions. 16. Deep Foundations-Lateral Load Capacity. Batter Piles. Response to Lateral Loads. Methods of Evaluating Lateral Load Capacity. p-y Method. Evans and Duncan's Method. Group Effects. Improving Lateral Capacity. 17. Deep Foundations-Design. Design Service Loads and Allowable Definitions. Subsurface Characterization. Foundation Type. Lateral Load Capacity. Axial Load Capacity. Driveability. Structural Design. Special Design Considerations. Verification and Redesign during Construction. Integrity Testing. IV. SPECIAL TOPICS. 18. Foundations on Weak and Compressible Soils. Deep Foundations. Shallow Foundations. Floating Foundations. Soil Improvement. 19. Foundations on Expansive Soils. The Nature, Origin, and Occurrence of Expansive Soils. Identifying, Testing, and Evaluating Expansive Soils. Estimating Potential Heave. Typical Structural Distress Patterns. Preventive Design and Construction Measures. Other Sources of Heave. 20. Foundations on Collapsible Soils. Origin and Occurrence of Collapsible Soils. Identification, Sampling, and Testing. Wetting Processes. Settlement Computations. Collapse in Deep Compacted Fills. Preventive and Remedial Measures. 21. Reliability-Based Design. Methods. LRFD for Structural Strength Requirements. LRFD for Geotechnical Strength Requirements. Serviceability Requirements. The Role of Engineering Judgement. Transition of LRFD. V. EARTH RETAINING STRUCTURE ANALYSIS AND DESIGN. 22. Earth-Retaining Structures. Externally Stabilized Systems. Internally Stabilized Systems. 23. Lateral Earth Pressures. Horizontal Stresses in Soil. Classical Lateral Earth Pressure Theories. Lateral Earth Pressures in Soils with c ...o and ... ...o 0. Equivalent Fluid Method. Presumptive Lateral Earth Pressures. Lateral Earth Pressures from Surcharge Loads. Groundwater Effects. Practical Application. 24. Cantilever Retaining Walls. External Stability. Retwall Spreadsheet. Internal Stability (Structural Design). Drainage and Waterproofing. Avoidance of Frost Heave Problems. 25. Sheet Pile Walls. Materials. Construction Methods and Equipment. Cantilever Sheet Pile Walls. Braced or Anchored Sheet Pile Walls. Appendix A: Unit Conversion Factors. Appendix B: Computer Software. References. Index.

Abstract: Load and Resistance Factor Design criteria for steel building structures were developed from first-order (second-moment) probabilistic principles in a research project described in this paper. The underlying assumptions, the probabilistic basis, the calibrations process, and the final format are examined. Specifically, the paper concerns itself with the background and the choice of the particular first-order model, with the data bases used in evaluating the loading and the resistance functions, the choice of the safety index, and with the final selection of the load and resistance factors. Load combinations and serviceability as well as maximum strength criteria are tested.

Abstract: This paper describes the underlying theory, and a general-purpose computer program, VIPASA, for determining the critical buckling stresses or natural frequencies of vibration of thin prismatic structures, consisting of a series of plates rigidly connected together along longitudinal edges. Each plate may be either isotropic or anisotropic and may carry a basic stress system consisting of longitudinal and transverse direct stress combined with shear. The structure is assumed to be subjected to a “dead load” system which does not cause buckling; in addition a “live load” system, defined in magnitude by a single load factor, may be applied and the value of the load factor at buckling is determined. Alternatively the natural frequencies of vibration of the structure when subjected to the dead load system are determined. Any number of critical load factors or natural frequencies can be obtained. The theory is based upon the assumption that all modes are sinusoidal, in the sense that all three components of displacement vary sinusoidally along any longitudinal line, but phase differences are incorporated to allow for the effects of anisotropy and shear. Apart from this assumption no further approximations are made other than those inherent in thin plate theory.