### 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.

### Newmark Deformations

This example demonstrates how the results of a QUAKE/W analysis can be used in conjunction with SLOPE/W to estimate the permanent deformations that may occur as a result of the inertial forces associated with an earthquake. This type of permanent deformation analysis is referred to as a Newmark analysis.

### Soil-Structure Interaction

The response of the ground can be influenced by the rigidity of a structure. Stated conversely, the presence of a stiff structure could possibly affect the response of the ground to earthquake shaking. This example illustrates some modeling techniques used to include the effects of a structure, including the mass of the structure, in a QUAKE/W analysis.

### Upper San Fernando Dam

The San Fernando earthquake occurred in California in 1971. The earthquake created a liquefaction failure at the Lower San Fernando Dam and Reservoir. This analysis demonstrates the advantages of using QUAKE/W with other GeoStudio products to analyze the multiple issues that arose with this case.

Draw the regions in your domain using CAD-like drawing tools, including drawing polygon and circular regions, coordinate import, copy-paste geometric items, length and angle feedback, region splitting and merging, and direct keyboard entry of coordinates, lengths, and angles. Alternatively, import AutoCAD DWG or DXF files directly into GeoStudio to create your domain geometry.

Define the material properties for your analysis, assign them to regions on the domain, and then define your initial pore-water pressure and stress conditions. Define materials using linear elastic, equivalent linear and nonlinear parameters and functions, such as pore-water pressure vs. cyclic number, Ka vs. shear stress, and more. Define the initial stress and pore-water pressure conditions for transient scenarios using results from other GeoStudio analyses, defined spatial functions or draw an initial water table.

Define stress/strain boundary conditions to simulate stress and fluid pressure conditions or displacement/force conditions to be placed on the domain. Time-varying loading functions can be defined to simulate changing conditions over the duration of a transient analysis. Structural beams and bars can also be applied to the model domain.

Open Draw Mesh Properties to refine the mesh drawn on the entire domain, or along specific geometric regions, lines or boundaries. Define history points at locations where complete records are required for all time steps included in the earthquake record. Information for all other nodes is typically saved every 10th time step.

When the Solver is finished, the Y-total stress contours are displayed, with displacement results displayed as either a deformed mesh or vector arrows. You can display other contours, based on displacement, velocities, accelerations, total or effective stress, pore-water pressure, and more, using the Draw Contours window or add acceleration vectors. Labels can be added to contour lines in Results View. Liquefaction zones can also be viewed on the model domain.

Interactively select any node or gauss region to view result information, including resulting total stresses, displacement, pore-water pressure, material properties, and more. Draw Mohr Circles to review the stress/strain state of any node or gauss region. Display plots of computed results over the x or y-direction, create time-varying plots of results in transient analyses or view result graphs at history points, such as displacements, velocities, total or effective stresses, and more. Generate reports of the definition and results, and export into other applications such as Microsoft Excel for further analysis.

## 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 that may affect the stability of the structures. The shaking may also generate excess pore-water pressures. Both the dynamic stress conditions and the generated pore-water pressures can be used in SLOPE/W to study how an earthquake affects the earth structure stability and deformation.

### QUAKE/W results in SEEP/W

The QUAKE/W computed excess pore-water pressures generated during an earthquake can be taken into SEEP/W to study how long it will take for the excess pore-water pressures to dissipate.

### SIGMA/W stresses in QUAKE/W

Establishing insitu static stresses can be done simplistically in QUAKE/W. Alternatively, you can use the load sequencing and non-linear constitutive soil models in SIGMA/W to improve the estimation of the static stress conditions, and then use them as the initial static stresses in a QUAKE/W dynamic analysis.

### QUAKE/W results in SIGMA/W

Stress results from QUAKE/W can be used in a SIGMA/W stress redistribution analysis.