With increasing congestion in modern cities we are turning more often to underground transportation systems, finding ourselves not only tunnelling under existing structures, but often also under existing tunnels.
Ground movement is an inevitable risk to nearby structures which must be carefully assessed, both at the planning stage and as the project unfolds. This, in addition to the potential negative effect on the safety of construction and the project cost, means that the ability to make these predictions accurately is a key. Surface settlement caused by shallow tunnel construction in greenfield sites can be predicted with some confidence. However, surface settlement in urban areas presents a much more complex interaction between the tunnel and its shafts, the ground and the building.
Why use DIANA?
DIANA has a number of uses in tunnelling and underground construction projects. Analyses normally focus on tunnel induced settlement or lining stress analysis, but DIANA can also be used to research how a tunnel may react in the event of a fire, explosion or seismic event.
Using the DIANA software you are able to create detailed 2D and 3D analyses of the interaction between the building, the ground and the tunnel and its shafts.
The analysis of existing and new build tunnel linings, following structural damage, freezing, fire, flood, or earthquake are critical to the safety and longevity of the tunnel. With DIANA, a model of the tunnel segments and joints, along with the soil and grout pressures upon it, and potential factors listed above can be analysed to show inherent deformations.
In addition to the tunnel specific technical data and specifications below, see also the general functionality information (to the right of this page). Our range of brochures are also available for download. Or, if you have a specific question about DIANA that you would like to ask, please use the webform.
Dedicated Features for the Analysis of Tunnels & Underground Structures
- In-situ Stress ( Ko procedure/gravity loading/pre-stress) and Pore-pressure Initialization
- Drained / Undrained Analysis
- Construction-staged analysis
- Seepage analysis (steady state / transient)
- Saturated or Partially Saturated Flow
- Consolidation analysis (full coupled stress-flow analysis)
- Pressure dependent degree of saturation
- Porosity or saturation dependent permeability
- Deformation dependent density and porosity
- Large displacement and large strain nonlinear analysis
- Special elements for nonlinear modeling of joints between the TBM lining segments
- Ground freezing analysis including latent heat consumption, thermal expansion and temperature dependent elasto-plasticity
- Generalized plane strain elements for 2D modeling of inclined tunnels or shafts in strongly anisotropic in-situ stresses
- Mesh-independent embedded bars and grids that allow easy modelling of:
- rock bolts, nails or geotextiles in solid soil elements
- reinforcement in beam or shell structural elements
- Soil-structure interaction with non-linear behaviour for both soil and structure
- Wide range of material models for the analysis of non-linear concrete material behavior
- Transient nonlinear analysis for viscous behaviour such as creep, shrinkage or swelling, ambient influence such as temperature or chemical concentration
- Young concrete analysis including hydration heat, shrinkage, hardening, visco-elasticity and cracking
- Higher order solid elements up to cubic interpolation
- Mohr-Coulomb, Tresca
- Drucker-Prager, Von Mises
- Transversely Isotropic
- Duncan-Chang
- Hoek-Brown
- Jointed Rock
- Modified Cam-Clay
- Jardine (London clay)
- Modified Mohr-Coulomb (Cap model)
- Special Interface Models
- User Supplied Subroutine
- Discrete cracking with interface elements
- Multi-directional Fixed crack model with strain decomposition
- Total-strain crack models with fixed and rotating cracks for tensile and compressive failure
- Fiber reinforced material models
- Creep and shrinkage models according to different international design codes
- Classic brick model for soil
- Eigenvalue analysis (eigenfrequencies, eigenmodes, participation factors, effective masses)
- Direct frequency response analysis
- Modal frequency response analysis
- Spectral response analysis (ABS, SRSS, and CQC modal combinations)
- Linear and nonlinear time domain analysis (total, transient and steady state, solution)
- Various time integration methods, e.g. Newmark, Wilson-theta, Runge-Kutta
- Hybrid Frequency-time domain analysis (steady state solution)
- Fluid-structure interaction
- Multi-directional base acceleration loads
- Prescribed nodal acceleration loads (release summer 2011)
- Distributed mass elements (2D line elements + 3D surface elements)
- Bounding/boundary elements for far field behavior (2D line elements + 3D surface elements)
- Viscous, structural, and continuous damping
- Specified or calculated initial conditions
- Consistent or lumped mass and/or damping matrices
- Towhata-Iai liquefaction model (2D models and largely undrained conditions)
- Nishi liquefaction model (for 2D/3D, partially drained conditions, arbitrary shearing direction)
- Bowl liquefaction model (for 2D/3D, partially drained conditions, horizontal shearing)
- User-supplied liquefaction models (USRLIQ subroutine)
