Structural Analysis and Design to Eurocodes

Multifunctional research and sports center at 1 T. Daugirdo St., Kaunas, using LIRA-FEM and LIRA-CAD in accordance with the Eurocodes

The purpose of this article is to demonstrate the capabilities of LIRA-FEM and LIRA-CAD for a complete cycle of structural analysis in accordance with the Eurocodes.

Project description:

Characteristics

-Consequence class by LST EN 1990:2004 – CC3.

-Reliability class by STR 2.05.03:2003 – RC2.

-Design working life by LST EN 1990:2004 – 50 years.

-Building type by use by STR 1.01.03:2017 – Non-residential building, subgroup (7.11) - buildings for research and educational purposes.

-Category by STR 1.01.03:2017 – special buildings.

-Type of construction by STR 1.01.08:2002 – new construction.

Main design solutions

The research and sports center has plan dimensions of 85 × 32.8 m. The building height is 13.75 m from the design elevation ±0.00. The floor level of the lowest storey is at elevation –3.9 m (relative to ±0.00).

The main load-bearing structures are cast-in-place reinforced concrete. The roof load-bearing structures are steel with timber rafters. The building is divided into two temperature zones and is constructed in three stages.

Interaction with adjacent buildings:
The building has no rigid structural connection to the existing buildings and is separated from them by retaining walls and an expansion joint.

Structural system

Cast-in-place reinforced concrete foundations on bored piles. The perimeter of the underground part is formed by pile walls. Cast-in-place reinforced concrete plinth beams; walls of staircases and elevator shafts; columns; floor slabs (beam-and-slab systems are used in zones with high loads). Pitched roofs are supported by steel trusses and timber rafters. Slabs are rigidly connected to columns and walls. Columns are cast-in-place reinforced concrete. Staircase walls and elevator shafts are flexibly connected to the foundations. Steel beams and trusses are hinged to reinforced concrete structures.

Stages of model generation

LIRA-CAD 

The model was fully developed in LIRA-CAD. All main load-bearing elements were modelled, with cross-sections, structural elements, material properties, boundary conditions and loads defined. Area loads were automatically converted into line loads applied to each rafter.

LIRA-FEM

Local model issues were refined in LIRA-FEM, and three different models were created for nonlinear analysis by ULS, SLS Characteristic and SLS Quasi-permanent. Nonlinear tension-only elements were also used to model braces that work only in tension

Load application

Permanent loads (LC1–LC7)

• LC1: self-weight of structures;
• LC2: permanent load on floor slabs;
• LC3: facade load;
• LC4: soil pressure.
• LC5: equipment load
• LC6-LC7: load from the retractable grandstand (2 cases)

Imposed loads (LC9–LC12)

• LC9: loads according to the intended use of the premises;
• LC10: loads from internal partitions, equipment, etc..
• LC11-LC12: load from the retractable grandstand (2 cases)

Climatic loads (LC13–LC18)

• LC13-LC14: snow loads (2 cases + snow drifts);
• LC15–LC18: wind loads in four directions (X+, X–, Y+, Y–).

3.1 Snow

3.2 Wind

                             

                                                                                               

Load combination tables were generated automatically. The safety factors for variable loads were changed from 1.5 to 1.3 in accordance with the Lithuanian National Annex to Eurocode LST EN 1991-1-1. The dynamic effects that may occur in the grandstand area were also taken into account

5. Analysis results: horizontal wall reinforcement.

Construction process