ERIES-ColCap

2024 - 2026

Seismic Eng.

Andrea Orgnoni

Carlo Fontana

João Pacheco de Almeida

António A. Correia

Madalena Ponte

Filipe L. A. Ribeiro

+3 more

GEM Taxonomy string

CR/LFM

2024 - 2026

Seismic Eng.

GEM Taxonomy string

CR/LFM

Experimental assessment of the Collapse Capacity of code-compliant RC frames

ERIES-ColCap

RC STRUCTURES

Dataset Description

The ERIES-ColCap project advanced the understanding of the actual collapse capacity of reinforced concrete frame buildings designed to modern seismic design codes. The experimental program was conducted at the shake-table facility of the National Laboratory for Civil Engineering (LNEC) in Lisbon, Portugal. Two full-scale 3D reinforced concrete frames, designed to a given level of seismic intensity, selected to match the hazard for which the two specimens have been designed, were dynamically tested under unidirectional and bidirectional ground shaking. The tests were terminated only when the structures were deemed to have reached a close-to-collapse damaged state, and to thus pose a risk to the life of its hypothetical occupants.

The main objectives of the proposed project were to: assess the actual seismic capacity of the contemporarily designed RC members and structures; evaluate how currently available capacity formulae fare against the experimental observations; provide high-quality data for validation and improvement of numerical modelling strategies used to predict structural collapse; stimulate the potential revisiting of collapse fragility models for RC structures designed according to modern seismic codes; and launch an International Blind Prediction Competition.

RC moment frames

Shake-table testing

Collapse

Eurocode 8

Specimens

1. CC1D

The two test specimens consisted of full-scale reinforced concrete 3D frames featuring two storeys that are 4.25 x 5.75 m2 in plan and 3 m in interstorey height, with one-bay in each direction and column dimensions of 25 x 25 cm2 and beams with 20 x 30 cm2. They were designed using the performance requirements prescribed in the second generation of Eurocode 8. Additional masses were placed in both floor slabs, consisting of 6 masses of 0.59 ton and 4 masses of 1.13 ton per slab. The weight of the specimens was close to 40-ton, and the maximum horizontal capacity that might be developed by these specimens was preliminarily estimated as being equal to around 150 kN.

Specimen CC1D was tested only in the East-West direction, corresponding to the direction along the largest span of the one-bay moment frame.

1. CC1D Shake-table test

The RC frame units were tested on the large 3D shake table at the National Laboratory for Civil Engineering (LNEC) in Lisbon, Portugal. The maximum capacities of the horizontal actuators are 700 kN in the west-east (WE) direction and 500 kN in the north-south (NS) direction. The shake table can achieve maximum displacements and velocities of ±200 mm and ±700 mm/s, respectively, in either direction. The table has a maximum payload capacity of approximately 40 tons.

The RC frames were designed as if located in Bologna, Italy, in soil type A. The chosen input motion was the Montenegro 1979 earthquake (record ME-1979-0003), which has a spectral shape similar to the one of Eurocode 8. It is a long signal, with a significant duration larger than 12 s and a CAV larger than 690 cm/s. It was slightly modified in order to be compatible with the shake table limits for a maximum scaling of 300%.

The dynamic test of unit CC1D included 14 different levels of ground (input) motion (GM1 – GM14), with increasing amplitude but also including repetitions and smaller amplitude aftershocks (see Table 1). The HNE ground motion component was applied in the WE direction of the shake table.

Instrumentation

The dataset includes conventional data (i.e. wire potentiometers, LVDTs, accelerometers and strain gauges) and motion capture data with a Qualysis system tracking the kinematics of 200 points on each test specimen.

2. CC2D

Specimen CC2D is completely similar to CC1D, including concrete casting at the same dates. CC2D was tested for bidirectional input motions.

1. CC2D Shake-table test

The experiment information is the same as described for CC1D, with the difference that the input motion was bidirectional. The HNE ground motion component was applied in the WE direction of the shake table, while the HNN component was applied in the NS direction. For comparison purposes, besides the 14 ground motion levels applied to CC1D but now in both directions, two additional test stages included the unidirectional motion for 25% and 50% applied to CC1D.