A finite element limit analysis (FELA) uses optimisation techniques to directly compute the upper or lower bound plastic collapse load (or limit load) for a mechanical system rather than time stepping to a collapse load, as might be undertaken with conventional non-linear finite element techniques. The problem may be formulated in either a kinematic or equilibrium form. [1] [2]
The technique has been used most significantly in the field of soil mechanics for the determination of collapse loads for geotechnical problems (e.g. slope stability analysis). An alternative technique which may be used to undertake similar direct plastic collapse computations using optimization is Discontinuity layout optimization.
Geotechnics is the application of scientific methods and engineering principles to the acquisition, interpretation, and use of knowledge of materials of the Earth's crust and earth materials for the solution of engineering problems and the design of engineering works. It is the applied science of predicting the behavior of the Earth, its various materials and processes towards making the Earth more suitable for human activities and development.
The cone penetration or cone penetrometer test (CPT) is a method used to determine the geotechnical engineering properties of soils and delineating soil stratigraphy. It was initially developed in the 1950s at the Dutch Laboratory for Soil Mechanics in Delft to investigate soft soils. Based on this history it has also been called the "Dutch cone test". Today, the CPT is one of the most used and accepted soil methods for soil investigation worldwide.
Limit load is the maximum load that a structure can safely carry. It's the load at which the structure is in a state of incipient plastic collapse. As the load on the structure increases, the displacements increases linearly in the elastic range until the load attains the yield value. Beyond this, the load-displacement response becomes non-linear and the plastic or irreversible part of the displacement increases steadily with the applied load. Plasticity spreads throughout the solid and at the limit load, the plastic zone becomes very large and the displacements become unbounded and the component is said to have collapsed.
The Atterberg limits are a basic measure of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit.
Ground–structure interaction (SSI) consists of the interaction between soil (ground) and a structure built upon it. It is primarily an exchange of mutual stress, whereby the movement of the ground-structure system is influenced by both the type of ground and the type of structure. This is especially applicable to areas of seismic activity. Various combinations of soil and structure can either amplify or diminish movement and subsequent damage. A building on stiff ground rather than deformable ground will tend to suffer greater damage. A second interaction effect, tied to mechanical properties of soil, is the sinking of foundations, worsened by a seismic event. This phenomenon is called soil liquefaction.
The Bridge Software Institute is headquartered at the University of Florida (UF) in Gainesville, Florida. It was established in January 2000 to oversee the development of bridge related software products at UF. Today, Bridge Software Institute has a leadership position in the bridge software industry and Bridge Software Institute products are used by engineers nationwide, both in state Departments of Transportation and leading private consulting firms. Bridge Software Institute software is also used for the analysis of bridges in various countries by engineers around the world.
Slope stability analysis is performed to assess the safe design of a human-made or natural slopes and the equilibrium conditions. Slope stability is the resistance of inclined surface to failure by sliding or collapsing. The main objectives of slope stability analysis are finding endangered areas, investigation of potential failure mechanisms, determination of the slope sensitivity to different triggering mechanisms, designing of optimal slopes with regard to safety, reliability and economics, designing possible remedial measures, e.g. barriers and stabilization.
SVSLOPE is a slope stability analysis program developed by SoilVision Systems Ltd.. The software is designed to analyze slopes using both the classic "method of slices" as well as newer stress-based methods. The program is used in the field of civil engineering to analyze levees, earth dams, natural slopes, tailings dams, heap leach piles, waste rock piles, and anywhere there is concern for mass wasting. SVSLOPE finds the factor of safety or the probability of failure for the slope. The software makes use of advanced searching methods to determine the critical failure surface.
Discontinuity layout optimization (DLO) is an engineering analysis procedure which can be used to directly establish the amount of load that can be carried by a solid or structure prior to collapse. Using DLO the layout of failure planes, or 'discontinuities', in a collapsing solid or structure are identified using mathematical optimization methods. It is assumed that failure occurs in a ductile or 'plastic' manner.
Sarada Kanta Sarma is a geotechnical engineer, emeritus reader of engineering seismology and senior research investigator at Imperial College London. He has developed a method of seismic slope stability analysis which is named after him, the Sarma method.
Lyesse Laloui is a Chair professor of Soil Mechanics, Geo-engineering and CO2 storage at the School of Architecture, Civil and Environmental Engineering of the École Polytechnique Fédérale de Lausanne(EPFL). He is the director of the Civil Engineering Section. Laloui is also adjunct full professor at the Pratt School of Civil and Environmental Engineering of Duke University as well as advisory professor at the department of Civil engineering and Transportation of Hohai University, China. He is the vice-chair of the Technical Committee TC101 of the International Society of Soil Mechanics and Geotechnical Engineering. He is the Editor-in-Chief of the International Journal Geomechanics for Energy and the Environment. He is also Associate Editor of Frontiers in Carbon Capture, Storage, and Utilization, which is a section of Frontiers in Energy Research.
Geoprofessions is a term coined by the Geoprofessional Business Association to connote various technical disciplines that involve engineering, earth and environmental services applied to below-ground (“subsurface”), ground-surface, and ground-surface-connected conditions, structures, or formations. The principal disciplines include, as major categories:
Smoothed finite element methods (S-FEM) are a particular class of numerical simulation algorithms for the simulation of physical phenomena. It was developed by combining meshfree methods with the finite element method. S-FEM are applicable to solid mechanics as well as fluid dynamics problems, although so far they have mainly been applied to the former.
The Sarma method is a method used primarily to assess the stability of soil slopes under seismic conditions. Using appropriate assumptions the method can also be employed for static slope stability analysis. It was proposed by Sarada K. Sarma in the early 1970s as an improvement over the other conventional methods of analysis which had adopted numerous simplifying assumptions.
Limit analysis is a structural analysis field which is dedicated to the development of efficient methods to directly determine estimates of the collapse load of a given structural model without resorting to iterative or incremental analysis. For this purpose, the field of limit analysis is based on a set of theorems, referred to as limit theorems, which are a set of theorems based on the law of conservation of energy that state properties regarding stresses and strains, lower and upper-bound limits for the collapse load and the exact collapse load.
David Malcolm Potts is a professor of Analytical Soil Mechanics at Imperial College London and the head of the Geotechnics Section at Imperial College. He has been a member of the academic staff at Imperial College since 1979, responsible for teaching the use of analytical methods in geomechanics and the design of slopes and earth retaining structures, both at undergraduate and postgraduate levels.
The Interference of the footings is a phenomenon that is observed when two footings are closely spaced. The buildings when are to be constructed nearby to each other, the architectural requirements or the less availability of space for the construction forces the engineers to place the foundation footings close to each other, and when foundations are placed close to each other with similar soil conditions, the Ultimate Bearing Capacity of each foundation may change due to the interference effect of the failure surface in the soil.
Gyanendra Nath Pande or Gyan N Pande is Emeritus Professor at Centre for Civil & Computational Engineering, Swansea University and founder President of the International Centre for Computational Engineering (IC2E).
Medhat Haroun was an Egyptian-American expert on earthquake engineering. He wrote more than 300 technical papers and received the Charles Martin Duke Lifeline Earthquake Engineering Award (2006) and the Walter Huber Civil Engineering Research Prize (1992) from the American Society of Civil Engineers.
Scott William Sloan FRS FREng FAA FTSE was laureate Professor of Civil Engineering at the University of Newcastle.