RIDO Geotechnical software

The RIDO software calculates the elastoplastic balances of a curtain of molded walls, Berlin walls, sheet piles, etc., as well as a pile in the presence of soils of various natures.

The calculation resumes phase by phase the history of the work of implementation because it conditions the efforts mainly because of the irreversibility of behavior of the soil but also the incidence of the states of the geometry at the time of interventions like the setting In place of the butts or tie rods.

The elastoplastic equilibrium calculation of the curtain-soil-tensile complex is carried out in the modeling assumptions defined in FAGES-BOUYAT.

The WINCKLER hypothesis is certainly brutal, but sufficient for a technical calculation of dimensioning as shown by KASTNER-MASROURI-MONNET-FAGES and other references.

Unlike the PAROI program which determines the numerical solution of a system of integral equations, the RIDO software package results from an energy method with finite elements according to the “forces” model. It establishes the forces (soil reactions, tensions in tie rods etc.) that minimize the elastic energy of the curtain, tie rods, ground with linear conditions:

• equality for overall equilibrium, bilateral links …
• inequality for unilateral connections with soils and ties.

The resolution algorithm is an original adaptation of the primal-dual method applied to quadratic programming (elastic energy is a quadratic form of unknowns). See a similar treatment in DUPUIS-PROBST.

On the technical level, the RIDO software package version 4.20:

• Simulates excavations in each of the soils bounded by the curtain,
• Takes into account the slopes and risbrams (with calculation of stability of the risbe and automatic resizing) by their simple geometric description,
• Allows the redefinition of the characteristics of the soils in the cases of injections and backfilling,
• Can calculate the coefficients Ka and Kp by the resolution of BOUSSINESQ-RANKINE equilibrium equations integrated in the software package,
• Allows the direct introduction of active, resting and passive thrusts for particular cases (CULMANN method for example),
• Accepts displacements of the water table in each soil with or without pumping as well as the definition of suspended or captive aquifers,
• Automatically takes into account the effects of the hydraulic gradient on the apparent weight of the soil,
• Allows the installation and removal at any time of overloads of type CAQUOT, type BOUSSINESQ, type GRAUX, purely plastic type or directly defined by the user,
• Considers that the BOUSSINESQ overloads are linked to the state of the soil (thrust, abutment or elastic) as well as those of the CAQUOT type. However, their additive contribution can be used for control, although the superposition principle Does not apply in the elastoplastic model.
• Distinguishes between the case where the overloads are pre-existing and the case where they occur after the installation of the screen,
• Allows the installation, preloading, modification of their rigidity, the removal of butt or tie rods, both in bilateral and one-way connections with the curtain,
• Do not neglect, optionally, the buckling effect of the sheet piles held by tilted tie rods,
• Allows the placement and removal of a load distributed or concentrated at any position of the curtain,
• Supports the definition of elastic connections in displacement and rotation with a given structure (floors for example),
• Allows variable boundary conditions at the head and foot of the curtain,
• Accepts the modification of the curtain geometry during work (molding of the upper part of the curtain or molding at the advance of the excavation),
• Easily calculates the Berlin walls and “pants legs” walls,
• Considers long-term characteristics for both the floor and the curtain (Young’s modulus of concrete),
• Allows modifications of the elastic reaction modules of the ground to any phase,
• Automatically calculates the plug fault not only in case of equilibrium breakage but also when the curtain moves beyond a specified value in the data.
• A landslide can be simulated.
• At any stage of the sequence of physical phases, a limit-state test calculation may be requested. This will have no effect on the normal sequence of phases.
• Both for seismic calculation and for conventional calculation at the limit states of partial factors can be applied to loads and geotechnical data.
• Allows, in semi-automatic mode, the calculation of two interacting curtains.
• Allows calculation and verification according to Eurocodes 7 and their French adaptation NF P 94-282.