Structural engineering

Seismic Design Philosophy Modern seismic design philosophy for buildings is based on the concept of ductile failure modes that allow a structure to survive strong earthquakes without collapse, even when structural elements are damaged. The design approach recognizes that it is not economically feasible to design buildings to remain elastic during the largest expected earthquake. […]

Soil Mechanics Fundamentals Soil mechanics is the branch of civil engineering that studies the behavior of soils under loads and environmental conditions. The classification of soils is based on particle size distribution, with the USCS system dividing soils into coarse-grained soils such as gravels and sands, and fine-grained soils such as silts and clays. The

Principles of Structural Steel Design Structural steel is one of the most versatile and widely used construction materials for commercial, industrial, and institutional buildings. The American Institute of Steel Construction specification governs the design of steel structures in the United States using load and resistance factor design methodology. Steel grades commonly used in building construction

Structural Load Combinations The design of building structures must account for multiple types of loads that can act simultaneously. Building codes specify load combinations that combine dead loads, live loads, wind loads, snow loads, earthquake loads, and other forces in the most critical arrangements. The ASCE 7 standard provides the load combination equations used in

Types of Foundation Systems The selection of a foundation system is one of the most critical decisions in building design, as the foundation must safely transfer all building loads to the soil without excessive settlement or failure. Shallow foundations are used when the load-bearing soil is located near the surface, typically within 10 feet of

Why Soil Stabilization Is Needed Soil stabilization improves the engineering properties of soils that are inadequate for construction in their natural state. Problematic soils include expansive clays that swell when wet and shrink when dry, soft clays with low bearing capacity, loose sands that settle under load, and organic soils that continue to decompose. The

Why Buildings Need Retrofitting Building retrofitting is the process of strengthening existing structures to meet current code requirements and improve resistance to earthquakes, wind, and other loads. Many buildings constructed before modern seismic codes are vulnerable to damage or collapse during earthquakes. The 1994 Northridge earthquake in California caused over 40 billion dollars in damage,

Understanding Load Paths in Residential Framing The structural integrity and load path design of any building depends on a continuous load path that transfers all forces from the roof to the foundation. Every component in this path from the roof sheathing to the foundation footings must be properly connected to ensure that loads are distributed

Types of Retaining Walls Retaining walls are structures designed to hold back soil and resist lateral earth pressure. , and proper drainage systems for retaining walls should be verified during constructionGravity retaining walls rely on their own weight to resist overturning and sliding. These walls are typically constructed from mass concrete, stone, or concrete masonry

Site Investigation Methods Soil testing and site investigation are critical first steps in foundation design. The investigation program determines soil stratigraphy, groundwater conditions, and engineering properties of each soil layer. A typical investigation begins with a desk study reviewing existing geological maps, aerial photographs, and nearby project records. This is followed by field exploration and