Deep Foundation Design and Construction Deep foundations are used when the surface soils are not adequate to support the structure loads and competent bearing strata are located at greater depths. The two main categories of deep foundations are driven piles and drilled shafts, each with specific advantages and limitations depending on the soil conditions, the […]
Seismic Retrofitting of Existing Buildings Seismic retrofitting is the modification of existing structures to improve their resistance to earthquake ground shaking. Many buildings constructed before the adoption of modern seismic codes are vulnerable to damage or collapse during earthquakes. The retrofitting of these buildings is essential for reducing the seismic risk in earthquake-prone regions. The
Bridge Inspection and Evaluation Bridge inspection is the systematic examination of bridge components to assess their condition and identify any defects or deterioration that could affect the structural performance. The National Bridge Inspection Standards require that all bridges on public roads be inspected at regular intervals not exceeding 24 months. The inspection includes a visual
Retaining Wall Types and Selection Retaining walls are structures designed to hold back soil and resist lateral earth pressures in situations where the ground elevation changes abruptly. The selection of the retaining wall type depends on the height of the retained soil, the soil conditions, the space available for the wall base, the aesthetic requirements,
Masonry Structural Design Masonry is one of the oldest building materials, with a history spanning thousands of years from the pyramids of Egypt to modern reinforced masonry buildings. The structural design of masonry follows the strength design method in the Masonry Standards Joint Committee code, which uses load and resistance factor design principles similar to
Structural Dynamics and Earthquake Engineering Structural dynamics is the study of the response of structures to time-varying loads such as earthquakes, wind, and machinery vibrations. The dynamic response of a structure depends on its mass, stiffness, and damping characteristics. The natural frequency of vibration determines how the structure responds to dynamic loading, with the largest
Geotechnical Site Investigation Geotechnical site investigation is the systematic process of collecting information about the subsurface soil and rock conditions at a proposed construction site. The investigation program must determine the soil stratification, groundwater conditions, and the engineering properties of the materials that will affect the design and construction of foundations, earthworks, and pavements. The
Load Testing of Piles Static load testing of piles is the most reliable method for verifying the geotechnical capacity of deep foundations. The test involves applying a controlled load to the pile top and measuring the resulting settlement over time. The load is applied in increments using a hydraulic jack reacting against a heavy beam
Compression Members and Buckling The design of steel compression members is governed by the tendency of slender elements to fail by buckling at stresses below the material yield strength. The critical buckling load for a perfectly straight, elastic column was derived by Leonhard Euler in 1757 and remains the fundamental basis for column design today.
Steel Bridge Design Principles Steel bridges are among the most important infrastructure assets in the transportation network, providing efficient crossing solutions for roads, railways, and pedestrians. The design of steel bridges follows the AASHTO LRFD Bridge Design Specifications, which provide load and resistance factor design criteria for all bridge types. The primary structural components of
