Structural engineering

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The VST system enables solid, in-situ construction using prefabricated, permanent formwork.

The system is therefore invariant with respect to applied calculation standards, all concreting work taking place on location and only the property's concrete structure performing the support functions. This necessitates calculation and design for in-situ concrete construction.

Thanks to prefabrication, only the interfaces between the factory's and customer's reinforcements need to be considered -> naturally, the total must equal 100% of the reinforcement needing to be built in.

A coherent consideration of the interfaces between the factory and construction site entails a special analysis of the aspects mentioned below, as well as a check of own decisions and directives (in production and reinforcement plans) against these principles (assuming accurate statics):

• • Principle of producibility
  All elements and reinforcement guides must be designed to enable meaningful producibility (especially compliance with maximum dimensions, economic production process, technically correct design etc.).
• • Principle of ability to assemble
  All elements and reinforcement guides must be planned and produced so as to enable technically feasible, proper and economy viable assembly (provision of open corners, consideration of connecting reinforcements etc.).

Joint design in concrete construction is not as clean as in other structures, e.g. steel construction

Due to a use of connecting reinforcements, the structural detailing of concrete nodes usually exhibits a certain degree of rotational stiffness. Generally not considered in computations, this accordingly represents a system reserve. Also to be referred to here are current standards prescribing construction regulations.
In our area, real restraints and rigid frame nodes are used only for systems which need to remain kinematically immobile.

For a planned dissipation of horizontal forces exerted by wind, seismic or dynamic loads, systemic imperfections or exceptional strain, only specifically selected stiffening elements such as (completely continuous) stabilizing walls (stair and elevator cores, shear walls, etc.) should be used for absorption and secure transfer into the foundation.

For this purpose, a group of walls with a sufficiently large moment of inertia in both main directions is required. This generally poses no problems during standard building construction. It is necessary to bear in mind (possible) architecture-related, systemic changes leading to wall diaphragms interrupted in the vertical section. During usage, these do not prove viable as sole bracing elements. Because of the strength-related, mechanical distribution of forces attributable to the rigidity of the bracing elements, long walls absorb a large part of these forces. A full breakdown of forces, including a consideration of very short elements, appears to be unnecessary - just as addition of the rigidities aligned normally with respect to the main direction (nearly zero). Recommended finally is an assessment of the tension levels due to interaction / superposition of horizontal and vertical loads (especially the proportion of self weight) in order to identify any possible tensile forces (gaping joint). In individual cases, we construct load-bearing structures so as to preclude tensile forces near the support sections.