# Modelling examples

Examples calculated with CODE_BRIGHT. The examples can be open with GiD.

Example of a problem using the file root_bcf.dat to make a boundary condition variable with time. A time series can be input for any of the boundary condition parameters.
For complex constitutive model calibration it is sometimes necessary to simulate the experiment itself using CODE_BRIGHT. The geometry is simple. Test protocol is described by several intervals. For each interval, the stress changes thus leading to a loading and unloading protocol. During the test, impoundment may occur. Inundation is achieved by a hydraulic boundary condtion change from negative pressure to athmosferic pressure.
A swelling pressure test consist in the impoundment of a material subjected to constant volume conditions. The resulting stress that develops due to swelling of the material by reduction of suction is called swelling pressure.
A triaxial test can be easity simulated by a simple 2D geometry plus axisymmetric conditions. The boundary conditions are simple, for lateral surface (line) it is a constant stress (sigma3) and on top of the sample the constant stress (sigma3) is combined by a prescribed displacement rate that induces a variation of stress. Then, sigma1 = sigma3 + increment_sigma. The use of a simulation for a triaxial test calibration is specially necessary when dealing with complex constitutive models (Cam-Clay and BBM).
Simple mechanical calculation to show how the creep simple equation can be combined with linear elasticity. Caver convergence may cause surface subsidence.
Simulation of an Oedometer test using CASM model.
This example is based on a freezing experiment. The temperature of a buried pipeline is subjected to -10 C to generate freezing conditions in the surrounding soil. More details about freezing and the incorporation in CODE_BRIGHT can be found in: Nishimura, S., Gens, A., Olivella, S. & Jardine, R. J. (2009). Ge´otechnique 59, No. 3, 159–171 [doi: 10.1680/geot.2009.59.3.159]
The model includes an interface that uses modified properties of BBM: Friction parameter M has been reduced by a factor R=0.6, Poisson ratio has been recalculated to 0.4 instead of 0.3 using the same factor, Swelling parameters for the interface are set to 0 (BBM model), Porosity has been increased to 0.6 (instead of 0.43) at the interface zone which increases permeability and reduces capillary pressure at the initial conditions, Parameters for hydraulic laws are the same as for the buffer. The model has been developed for GiD16. The pdf document explains this model among other cases.
Preliminary examples of modelling chemistry with CODE_BRIGHT are included in this section. The examples correspond to the version included as: CODE_BRIGHT_2022 _11
Simulation of the construction and longterm response of an embankment by layers using the unsaturated soil approach. Coupled flow and deformation is calculated including BBM for elastoplastic deformations.
The models here have been calculated with CODE_BRIGHT_2023_14. Both CheProf and CheMech are under development. Examples correspond to basic problems. Additional examples and other documents will be publishes as soon as they are available.
Swelling pressure test simulated with CB2023_14 using BExM. Parameters do not correspon to any specific experiment or material.