This paper presents the development of two new types of hybrid cross-laminated timber plates (HCLTP) with an aim to improve structural performance of existing cross-laminated timber plates (Xlam or CLT). The first type are Xlam plates with glued timber ribs and the second type are Xlam plates with a concrete topping. A numerical...
In October 2007 a series of seismic tests were carried out on a 7-storey building made of cross laminated (XLam) wooden panels in natural scale on a shaking table E-Defence in Japan within the SOFIE project. The paper presents calculation procedure, prediction of dynamic behaviour of the tested structure excited by the earthquake record "Kobe JMA 1995" and comparison between predicted, that means calculated and measured response. Due to blind prediction approach some construction details were not known before dynamic time history response calculation. Therefore some assumptions, engineering judgment and rough static analyses were needed to define all construction parts which were in modelling approach assumed as important and could have had influence on dynamic response of the analyzed structure. The most important assumptions related to the definition of the stiffness and load bearing capacity of mechanical connections, types of anchors and their positions in each floor level, were determined on the basis of static analysis where the structure was loaded with equivalent horizontal seismic forces and then were used in dynamic analysis. A mathematical model was developed in program SAP2000 where modal and time history analyses were carried out. Comparison of calculated and measured results is described and evaluated on the basis of the model assumptions and its simplification.
This paper presents the results of an experimental study whose objective was to investigate the behavior of a hybrid wood shear-wall system defined herein as a combination of traditional light-frame wood shear walls with post-tensioned rocking Cross-Laminated Timber (CLT) panels. The post-tensioned CLT panels in the hybrid system offer both vertical and lateral load resistance and self-centering capacities. The traditional Light-Frame Wood Systems (LiFS) provide additional lateral load resistance along with a large amount of energy dissipation through the friction of nail connections. Thus, a combination of these two types of structures, in which traditional light-frame wood shearwalls are utilized as structural partition walls, may provide an excellent structural solution for mid-rise to tall wood buildings for apartments/condos, where there is a need for resisting large lateral and vertical loads as well as structural stability. In this study, a real-time hybrid testing algorithm using a combination of time-delay updating and Newmark-Beta feed forward to reduce the undesirable effects of time delay was introduced. The top two-stories of a three-story building were modeled as a numerical substructure with the first story as the experimental CLT-LiFS substructure. The experimental results of the hybrid wall are presented and discussed in this paper.
This paper investigates the seismic analysis of multi-story cross laminated timber (XLAM) buildings. The influence of different parameters such as wall geometry, vertical load level, friction and, most importantly, connection stiffness, strength and ductility is assessed. Linear and nonlinear finite element (FE) analyses are carried out on a hypothetic four-story case study building. The XLAM building behaviour factors are derived for different cases using a simplified method. Values in the range of 2 to 3 have been obtained depending on whether monolithic or segmental walls are used. Further nonlinear dynamic analyses carried out on a part of the case study building show that friction may have a beneficial effect on the seismic resistance of XLAM buildings. However it is advised that its influence is conservatively neglected until further investigations are performed. Obtained results provide an important insight for both academics and practicing engineers into the FE modelling and design of XLAM buildings using different code-based approaches. This data is also crucial for the preparation of new seismic design codes on XLAM timber buildings.
This paper deals with the issue of seismic strengthening of existing older reinforced concrete frame buildings. A new method of strengthening by applying a new outer shell made of cross laminated timber (crosslam or Xlam) plates is presented. A seismic strengthening case study is presented on a 3 story reinforced concrete frame building. The results of shaking table tests of a (strengthened) two-story reinforced concrete frame with and without infill are presented.
The proposed retrofit system employs a new outer cross laminated timber jacket to stabilise a building against horizontal shear forces that are caused by earthquakes; on one hand the timber panels have a low mass and therefore don’t contribute much to seismic forces, however they are very stiff on the other hand and provide high shear resistance. The new outer shell could have windows, doors and a façade installed already in the manufacturing plant. Another positive aspect of the outer shell is that there are no harsh interventions to a building and that people don’t have to move out during the construction phase (unlike when using most of the conventional methods for seismic strengthening). On the other hand the installation of panels is also possible from the inside with little influence on the existing structure. All together it makes a unique system that prolongs the lifespan of constructions, contributing to sustainability. In the following chapters the system is presented more in detail as well as the results from dynamic shaking table tests of a reinforced two-story RC frame with masonry infill.
This paper deals with the seismic behaviour of timber-glass systems. A series of experiments was performed on the shaking table of the IZIIS institute in Skopje, Macedonia. One and two story full scale structures were subjected to a series of ground motions. All together 8 different setups were tested. The chosen combination of glass-timber walls exhibited a rocking type of behaviour, resulting in a desirable ductile failure of steel hold-downs and not brittle failure of the glazing or the timber frame.