Dag Pasquale Pasca

• Doctor of Engineering
• Researcher at Norwegian Institute of Wood Technology

Cross-laminated timber (CLT) floors often face vibration challenges in long spans under heavy loads, and improvements in their vibration performance typically focus on achieving composite action. This research evaluates the potential of hybrid CLT-steel composite floors as alternatives to conventional long-span CLT floors. The key parameters analyz...

This paper addresses the fire resistance of adhesive-free Cross-Laminated Timber (CLT) panels assembled with beech wooden dowels. A 180 mm thick, unprotected sample composed of six layers, each 30 mm thick, with overall dimensions of 3 m×3 m, was subjected to a standard fire curve for 100 min. The panel was loaded in-plane with a uniformly distribu...

This paper analyzes the effects of topographic amplification of seismic action in mountain ranges. Theoretically, amplification might be an issue for avalanches, landslides, and rockfall, which seismic events could trigger. The authors conducted a numerical and experimental analysis on a kilometre scale of a Gran Sasso mountain range segment in Ita...

This paper presents the continuous monitoring of an eight-story cross-laminated timber (CLT) building. The monitoring process includes daily acceleration measurements at the rooftop, along with external temperature, humidity, and wind velocity data. Additionally, moisture content (MC) of timber at various locations in the internal and perimeter wal...

Among the key benefits of using structural timber is its potential for reuse after being dismantled from an existing building. Recycling and reuse are central concepts in the circular economy. However, the installation and dismantling of structural elements often leave traces from previous use, such as holes from connectors like dowels or screws, i...

Cross-laminated timber (CLT) floors often encounter vibration issues when employed in large spans bearing heavy loads, and the enhancement of their vibration performance frequently centres around achieving composite action. This study delves into the effectiveness of hybrid CLT-steel composite floors as potential substitutes for traditional, long-s...

The most common and practical connection between CLT walls can be realized with inclined screws. This choice avoids the realization of more elaborated half-lap or spline joints. The failure mechanism of CLT-to-CLT screwed connections is highly ductile. However, the epistemic and aleatoric uncertainties associated with the capacity estimation of the...

Timber structures are susceptible to sound propagation problems. The issue can be mitigated by decoupling structural components at connections level by means of polyurethane soundproofing interlayers. These layers are much softer than timber but, at the same time, they are characterized by higher friction coefficients. In this paper, an experimenta...

Nowadays, some innovative spatial structural typologies among others rely on timber-concrete hybrid solutions for designing modern buildings. However, the dynamic identification analysis may be more elaborate, and sometimes troublesome, due to the coupling effects of the different dynamic nature of cross-laminated timber and reinforced concrete mem...

Inclined screws represent a typical connection solution for timber structures. They can provide higher capacity and stiffness due to the combined axial-shear interaction. This paper investigates the effect of engineering wood products choice (glued-laminated timber and cross-laminated timber), fibre inclination, friction, and interlayers on the cap...

Timber floors are prone to vibration due to the reduced modulus of elasticity of the material. Composite floors represent the most convenient solution to achieve acceptable performances and at the same time to save material and cost. In determining the natural frequency of a composite floor, the stiffness of the connection between the joined struct...

The paper presents an example of model updating of both the mass and stiffness parameters of a curved cable-stayed bridge in Venice (Italy). Conventional optimization problems of mass and stiffness using ambient vibration data are prone to ill-posedness and ill-conditioning, and generally, the scholar must assume one of the two to achieve a reliabl...

Timber floors can be susceptible to human-induced vibration due to the low density of timber compared to other construction materials. Human-induced vibration is a complex problem due to many involved parameters. As in many dynamic systems, the response depends on the dynamic parameters and the excitation source. Therefore, more advanced assessment...

Glue-line tests provide the shear resistance and failure mode of samples extracted from laminated timber products. Several papers questioned the practical use of such tests affirming the lack of correlation between the capacity of the beam and the outcomes of glue-line tests. However, no studies provide a probabilistic framework for interpreting gl...

Holes in timber beams can significantly affect their bearing capacity. This paper presents an extensive experimental investigation of the effect of circular holes with and without plywood reinforcement on glulam joists behaviour. The tests consider the variability of hole position, number and diameter. In the second step, a finite element model bas...

This paper presents and discusses the feasibility of complete model updating of cable-stayed bridges using experimental estimates of the cable forces and modal parameters. The procedure is applied to the model updating of a curved cable-stayed bridge in Venice (Italy). Conventional optimization problems of mass and stiffness using ambient vibration...

In recent years, different structural health monitoring (SHM) systems have been proposed to assess the actual conditions of existing bridges and effectively manage maintenance programmes. Nowadays, artificial intelligence (AI) tools represent the frontier of research providing innovative non-invasive and non-destructive evaluations directly based o...

In structural health monitoring (SHM) paradigm, operational modal analysis (OMA) comprises several techniques and algorithms for estimating the dynamic characteristics of a structure in operational conditions from its vibration response. The OMA method has been spreading in the last years due to multiple advantages compared to input–output identifi...

The paper discusses the possibility of reliably estimating the concrete resistance based on Young's modulus assessed from FE model updating using ambient vibration data. The procedure is applied to the FE model updating of a multi-span prestressed concrete bridge in Corvara (Italy). The bridge consists of seven spans, each made of seven prestressed...

p>The aging of existing concrete structures requires the development of economical and non- destructive (ND) methods to estimate their structural capacity. The practice of operational modal analysis (OMA) in civil structures is actually widespread, but there are a few applications that relate the estimate of the modal parameters to the ultimate res...

The paper presents and discusses the dynamic response of a curved cable-stayed bridge in Venice (Italy). Two distinct experimental campaigns in 2010 and 2011 led to identifying the bridge dynamic characteristics in operational conditions. The dynamic identification included the characterization of both the deck and cables response. The authors deve...

The size-dependent mechanical response of graphene is investigated with an entirely nonlinear molecular mechanics approach. Finite element (FE) simulations under uniaxial and equibiaxial tensile loads are carried out on graphene sheets with increasing size. It is found that the response of graphene remains unchanged after a threshold size. Furtherm...

Timber floors are prone to exhibit vibration levels, which can cause discomfort to the occupants. In the last 20 years, ambient vibration tests have become very popular due to the many advantages they have over traditional forced vibration tests when dealing with civil engineering structures. Furthermore, sensitivity analyses and black-box" optimiz...

The results of experimental tests conducted on the joints of a wood-based prefabricated sandwich panel recently developed in Norway are presented. The connections investigated were those involved in constituting the lateral-force-resisting system for a wall assembly, namely the panel-to-sill connections. Several European standards are undergoing a...

This paper delivers a reliability-based method for the assessment of the elastic modulus (EM) of concrete in simply supported girders from dynamic identification. The correlation between the natural frequencies of the first bending modes and the concrete EM supports the use of the first natural frequency as a predictor of the EM value, which is a w...

p>This paper presents the results of a study assessing the resistance of a recently developed standing wood-based prefabricated sandwich panel. The work was carried out in the framework of a product test, and consisted in a total number of 154 tests upon several different configurations. The connections investigated were those involved in constitut...

Cross-Laminated Timber (CLT) structures exhibit satisfactory performance under seismic conditions. This ispossible because of the high strength-to-weight ratio and in-plane stiffness of the CLT panels, and the capacity ofconnections to resist the loads with ductile deformations and limited impairment of strength. This study sum-marises a part of th...

Significant technical advances and developments in the field of timber connections within the last years have fostered the recent renaissance of timber as a structural material. An increased range of connection types and corresponding applications gives designers both opportunity and challenge. The result is a noticeable trend towards systemized so...