Last Updated October 18, 2019
Overview
QUAKE/W is a geotechnical finite element CAD software product for the dynamic analysis of earth structures subjected to earthquake shaking, or point dynamic forces from a blast or a sudden impact load. QUAKE/W determines the motion and excess pore-water pressures that arise due to shaking. Its comprehensive formulation makes QUAKE/W well suited to analyzing a wide range of problems.
Key Features
DYNAMIC STRESS ANALYSIS
QUAKE/W models dynamic stresses arising from earthquake shaking or dynamic point forces from a blast or sudden impact. QUAKE/W simulates the impact of these stresses on earth structures.
EARTHQUAKE RECORDS
Earthquake time history records can be imported and scaled for a dynamic analysis. Modify the peak acceleration and duration to ensure the values used in the QUAKE/W analysis represent site-specific conditions.
NEWMARK ANALYSES
The QUAKE/W computed dynamic forces can be used in SLOPE/W to compute yield accelerations and potential permanent deformations for each trial slip surface.
EXCESS PORE PRESSURE
Excess pore-pressures computed by QUAKE/W together with the initial static pore-pressures can be used in SLOPE/W to examine the effect of the elevated pore-pressures on stability.
QUAKE/W models liquefaction and dynamic loading
GROUND RESPONSE ANALYSIS
QUAKE/W can simulate ground motions to evaluate dynamic stresses and strains in earth and retaining structures. This allows for assessment of liquefaction hazards and the dynamic-induced forces that can lead to instability. The dynamic stress-strain analyses can be driven by an earthquake acceleration history or by static/dynamic loads on the ground surface (e.g. blast vibration). Earthquake time-history files can be imported directly into GeoStudio and scaled to different peak accelerations for rapid sensitivity analyses. Alternatively, acceleration, velocity, or displacement data can be pasted directly into user defined spline functions. Soil and rock stress-strain responses can be represented by linear, non-linear, or equivalent linear constitutive models and retaining structures by specially formulated structural elements.
LIQUEFACTION ASSESSMENT
Excess pore-water pressures during an earthquake
can lead to liquefaction and subsequent large-scale deformations or global failure. QUAKE/W simulates excess pore-water pressure generation using classical cyclic stress ratio and pore-water pressure relationships or by a functional relationship between volumetric straining (and therefore pore-water pressure response) to cyclic number. Liquefaction zones are identified by tracking stress paths relative to the collapse surface or by reducing effective confining stress. Liquefied zones are shown at each time step to better simulate deformations and assess stability.
STABILITY AND DEFORMATION ANALYSIS
Integration with SLOPE/W allows the factor of safety to be assessed at every dynamic analysis step using limit equilibrium or stress-based analyses. Liquefied zones identified by QUAKE/W can be assigned a steady-state strength to include the effects of strength loss. To calculate irrecoverable plastic deformation (e.g. settlement of a dam crest), use SLOPE/W with the simulated ground accelerations in a Newmark Deformation analysis. Alternatively, use SIGMA/W to compute permanent deformation by redistributing stresses within liquefied zones and other over-stressed areas. This allows for assessment of failure mechanisms and overtopping in earth structures or, when combined with structural elements, assessment of bending moments and shear stresses within retaining structures.
VIEWING THE ANALYSIS RESULTS
Once you have solved your analysis, QUAKE/W offers many tools for viewing results. Animate the motion by viewing the displacements for successive steps. Look at the complete displacement, velocity and acceleration history record at key points. Perform a spectral analysis at these points to study the ground motion frequency and seismic characteristics. Generate contours or x-y plots of stress, strain, pore-water pressure, and over 35 other parameters. Show the shaded liquefaction zone. View any stress state as a Mohr Circle with the associated space-force diagrams. Then prepare the results for your report by adding labels, axes, and pictures, or export the results into other applications such as Microsoft® Excel® for further analysis.
Typical Applications
QUAKE/W can model the dynamic behavior of almost any earth structure, including:
- Earth embankment dams
- Natural soil and rock slopes
- Loose ground deposits
- Estimation of post-earthquake deformation
- Impact loads from dynamic blasting
- Any natural, near-horizontal ground sites with potential for excess pore-water pressure generation during earthquake shaking
- plus many more!
The Power Of Integration
QUAKE/W offers simple but powerful analytical capabilities when used in combination with other GeoStudio products.
QUAKE/W RESULTS IN SLOPE/W
Earthquake shaking of ground structures creates inertial forces and excess pore-water pressures that may affect the structure’s stability. The dynamic stress conditions and pore-water pressures generated by QUAKE/W can be used in SLOPE/W to assess stability and deformation following an earthquake.
QUAKE/W RESULTS IN SEEP/W
The excess pore-water pressures generated during an earthquake may dissipate quickly or gradually depending on the soil properties. The pore-water pressure results from a QUAKE/W analysis can be inputted into SEEP/W to investigate excess pore-water pressure dissipation over time.
SIGMA/W STRESSES IN QUAKE/W
Establishing insitu static stresses can be done simplistically in QUAKE/W. For more complex systems, the static stress conditions may be simulated in SIGMA/W with the load sequencing and non-linear constitutive soil models, for example, and then imported into QUAKE/W as the initial conditions.