National Laboratory for Civil Engineering
Physical Sciences and Engineering
Development and updating of modules in a seismic scenarios simulator (LNECloss - a package of routines integrated in a GIS) used in seismic risk studies of urban regions and evaluation of optimized strategies for seismic risk mitigation through cost-effective (or cost-benefit) analyses.
The LNEC-3D shake table, over which the models to be tested are placed and fixed, has the shape of a triangular prism with the following characteristics: Platform dimension 4,6x5,6 m2 Maximum capacity of 40 tons Three independent orthogonal axes: displacements actively controlled, rotations passively restricted (torque tubes) Frequency range from 0 up to 40Hz The LNEC-3D shake table is capable of testing large civil engineering structures subjected to seismic actions of different intensities up to imminent collapse condition of structures or substructures. The specimens can be in real or reduced scale depending on the dimensions of the prototype. Due to its characteristics, the LNEC-3D shake table also allows to carry out dynamic tests for seismic qualification of equipment and components for the manufacturing industry and electric power distribution according to international standards.
Oil reservoir with a capacity of about 2000l Oil filters Pressure and return lines to each of the three substations associated with each axis. Three substations including oil accumulator banks. Group of three electrical pumps with an electric power of 330 kW, maximum flow rate of 690 l / min at a pressure of 23 MPa, being the electrical energy of the whole system supplied by a dedicated power station. Oil cooling system with an outdoor cooling tower using two pumps for water circulation. Electrical power supply cabinet of the entire oil-hydraulic system. Control and monitoring center (PLC) of the entire oil-hydraulic system, that allows activating the three pumps independently, and of all the refrigeration system components. It monitors the temperature, level and volume of oil in the tank and also the state of the star-triangle operation of each pump. All variables and alarm levels and auto start are set in the control center.
The "Testing methodology and apparatus for Innovative building solutions using Masonry walls” (TIM) was designed for performing innovative shake table tests of masonry walls, structural or non-structural, subjected to simultaneous in-plane and out-of-plane dynamic actions. Such tests require the use of the shake table in combination with the surrounding reaction walls. This device allows substructure tests to be performed, representative of the response of a building’s masonry wall, upon a biaxial seismic event. It thus contributes for the evolution of construction and structural strengthening techniques in that type of elements. Its design concept received the 2nd Young Engineer Innovation Award, in 2013, granted by the Portuguese Order of Engineers. Finally, the device can also be adopted as an auxiliary guidance structure for unidirectional tests of plane structures.
The testing room consists of various distinct areas: one models construction / demolition area, two test areas and one equipment area. The test areas contain the 3D and 1D shake tables, the strong floor and the control room. The equipment area includes the substations, the shake table pit and the electric pumps room. Two gates located on opposite facades give access to the models construction / demolition area and allow the entry and exit of materials, components and complete equipment. Main characteristics: Area (m2) ~450 Floor to ceiling height (m): 10 Clear height (m): ~7.5 Access gates (m): 5.0x4.5 (WxH) Inside the testing room there is also an overhead crane with 400kN capacity and speed control that allows the transportation of large specimens, enabling the use of the facility for repeated cycles of construction, instrumentation and removal of large specimens
The three reaction walls, built around the LNEC-3D shake table, have a maximum height of »7m and are able to support high horizontal forces, increasing the capacity of the equipment in terms of multiple seismic testing setups. Their combination with the LNEC-3D shake table allows carrying out quasi-static tests in one direction and simultaneously dynamic tests in the perpendicular direction. It also allows carrying out pseudo-dynamic tests and seismic tests of structural components with substructuring techniques.