NCH 433 Modification – Wood

The mission of the project is to develop and prove the proposal amendment of the construction and design regulations for timber buildings (NCH433 and NCH1198) in a way that allows the construction of medium-high building, efficient, economics and sustainable using platform-frame system.

In cooperation with Bio-Bio University, supported by COFO, MINVU as client, industry professionals and representatives and organizations as ACHISINA, CORMA and Institute of Construction, this project seeks the calibration of seismic performance component as an admissible value of mezzanine deformation or drift and response modification of  ‘’R’’ factor in the seismic design regulation for buildings NCH-433, this calibration will be carried out using the methodology of document FEMA-P695, which include a methodological, coherent and rational procedure to measure the collapse behavior of a structure and establish seismic performance factors for the proposed structural systems, these need a significant effort that involves materials test, structural components, connections, structural design of a wide set of building prototypes, creation of nonlinear models for each building and implementation of dynamic analysis for those models. In This way, a safe level of collapse is evaluated based on the response of the seismic resistant systems associated with an acceptable value of mezzanine deformation or drift.

The beginning of the project considers a bibliographic review of regulations, books, investigations, articles, design manuals and international building solutions established from a structural and fire protection point of view. In a second stage, biographical documentation that allows design building prototypes and complement all the necessary experimental development will be reviewed. The experimental campaign include materials test as OSB structural boards and wood of the wooden frame, also considers cyclicals shear tests on the OSB- Nail- Wood union, cyclical shear test on structural walls without axial load, monotonic shear and cyclical shear plus axial load with bending moment; the three actions will take part in the same test wall, these tests will add knowledge to the state of art of this type of structures, both due to the great magnitude of the axial load applied as for the fact of linking the moment in a cyclical shear test on a platform frame wall.

Throughout each step of the process it is described  the seismic design regulations, range of feasibility of the studio system, methodologies and essay results, the principles used for a rational selection of the system archetypes, evaluations of the quality of the information and qualification of associated uncertainties, results of performance evaluations, seismic behavior aspects found and also analytics results of the investigation. 

On the other side, the scope of the expansion of the wood design and building regulation NCH1198 includes provision that allow to know deflections and resistant capacities of shear walls and mezzanine diaphragm with different nail spacings. 

On the last stage of the project an economic analysis of medium-high timber building will be made. It will be chosen a 5-story social housing and a 6-story private housing, once designed ,the cost of these wooden building will be evaluated with the previous regulation in contrast with the new suggested changes for building seismic designs.