Pullout tests on the connection to an existing foundation of a steel warehouse rebuilt after the 2012 Emilia (Italy) earthquakes

The tests described in this paper were aimed at evaluating the tensile capacity of the anchorages connecting an automated pallet warehouse with an existing RC foundation. The warehouse is a new steel structure erected in the place of a previous warehouse collapsed due to the Emilia earthquake, but whose foundation remained undamaged. The investigated fastening consists of 10 post-installed, bonded threaded rods with diameter (d) and embedment depth (h(ef)) of 20 and 500 mm, respectively. Neither anchor arrangement nor embedment depth (h(ef) > 20d) was covered by current standards for fastening design. To reproduce the in-situ actual conditions of the fastening, an unconfined test configuration was used. The maximum loads achieved were more than 3 times greater than the seismic demand for the fastening. The tests highlighted the crucial role played by the reinforcing steel which was present in the foundation. Concrete-related failure mechanisms, such as the combined pullout and concrete cone failure mechanism typical of bonded anchors, were not activated. The observed crack patterns rather suggest the onset of a flexural failure mechanism of the concrete slab. This feature is confirmed by analytical calculations showing that, at the maximum loads achieved in the tests, the top reinforcement was likely to be yielded. In six preliminary unconfined tension tests on single anchors, steel rod failure was achieved, associated with limited cracking of the concrete surface in proximity of the anchor

A public early intervention approach to first-episode psychosis: Treated incidence over 7 years in the Emilia-Romagna region

AimTo estimate the treated incidence of individuals with first-episode psychosis (FEP) who contacted the Emilia-Romagna public mental healthcare system (Italy); to examine the variability of incidence and user characteristics across centres and years. MethodsWe computed the raw treated incidence in 2013-2019, based on FEP users aged 18-35, seen within or outside the regional program for FEP. We modelled FEP incidence across 10 catchment areas and 7 years using Bayesian Poisson and Negative Binomial Generalized Linear Models of varying complexity. We explored associations between user characteristics, study centre and year comparing variables and socioclinical clusters of subjects. ResultsThousand three hundred and eighteen individuals were treated for FEP (raw incidence: 25.3 / 100.000 inhabitant year, IQR: 15.3). A Negative Binomial location-scale model with area, population density and year as predictors found that incidence and its variability changed across centres (Bologna: 36.55; 95% CrI: 30.39-43.86; Imola: 3.07; 95% CrI: 1.61-4.99) but did not follow linear temporal trends or density. Centers were associated with different user age, gender, migrant status, occupation, living conditions and cluster distribution. Year was associated negatively with HoNOS score (R = -0.09, p < .001), duration of untreated psychosis (R = -0.12, p < .001) and referral type. ConclusionsThe Emilia-Romagna region presents a relatively high but variable incidence of FEP across areas, but not in time. More granular information on social, ethnic and cultural factors may increase the level of explanation and prediction of FEP incidence and characteristics, shedding light on social and healthcare factors influencing FEP

Bending tests to estimate the axial force in slender beams with unknown boundary conditions

This paper presents a static method for the axial load identification of slender prismatic beams with uncertain length and unknown boundary conditions as is typical of struts and ties of truss structures or tie-rods of arches and vaults. The proposed method requires the knowledge of the beam flexural rigidity only. Flexural displacements or curvatures are measured at five cross sections of the beam subjected to an additional concentred lateral load. Unlike analogous dynamic methods, any set of experimental data may be used in the identification algorithm. The proposed algorithm is verified by means of many numerical and experimental tests on beams having different boundary conditions. Excellent estimates of the axial forces are obtained when the greatest possible distance between sensors is adopted, even if in the presence of high values of the axial forces very accurate displacement measurements are required

Il cantiere rinascimentale ferrarese: dal rilievo tecnico-costruttivo al progetto di conservazione. La sfida posta dalla nuova classificazione sismica.

Cofin 2004. Sicurezza e conservazione degli edifici storici in funzione delle tipologie edilizie, della concezione costruttiva e dei materiali. Coordinatore Nazionale: Prof. L. Bind

Updating italian design guide CNR DT-205/2007 in view of recent research findings: requirements for pultruded FRP profiles

A discussion on some design rules for pultruded fiber-reinforced plastic (PFRP) profiles reported by guideline CNR DT-205/2007 from National Research Council of Italy is presented in the paper. At eight years after approval of this technical document, several changes and improvements are required following recent research findings, and supplemental design rules should be incorporated into a future revision. The general framework for the design of columns and beams is outlined. A new closed-form expression for the local buckling moment for beams in major-axis bending is presented

Cyclic test on a precast reinforced concrete column-to-foundation grouted duct connection

A full-scale specimen of a column-to-foundation grouted duct connection suited for buildings and industrial structures is tested in cyclic bending combined with axial compression. The positioning of the steel ducts along the sides of the column cross-section allows for using traditional reinforcement cages for the column, with longitudinal bars at both mid-side and corners of the cross-section. Splice length and amount of transverse reinforcement along the splice are defined based on Eurocode 2 provisions for laps of reinforcing bars. A total of 19 loading cycles are carried out, achieving a drift of 5.3% in correspondence of a degradation of 15% of the peak resistance. The shear slip measured at the column-foundation interface results to be smaller than 5% of the deflection. Conversely, to predict accurately the test results, the slip of the projecting bars within their ducts cannot be neglected. It is proposed to take account of this slip by introducing an apparent strain. For the tested specimen, the apparent strain turns out to be equal to the yield strain of the reinforcement. A comparison with a monotonic bending test, previously conducted on the same connection, shows a strongly smaller deformability when the loading protocol is cyclic. Hysteretic energy and drift ductility for the proposed connection are close to those concerning a cast-in-place specimen of comparable capacity, which was described in a recent paper. The test results show an over-strength of 1.4 and a gain in ductility of 1.8 compared with the design values of bending resistance and curvature ductility computed for the cross-section at the column-foundation interface

In-plane bending of Timoshenko beams in bilateral frictionless contact with an elastic half-space using a coupled FE-BIE method

Making use of a mixed variational formulation including the Green function of the substrate, a finite element model is derived for the static analysis of Timoshenko beams in bilateral frictionless contact with an elastic half-space. Numerical results are obtained by adopting locking-free Hermite polynomials for the Timoshenko beam and piecewise constant reaction over the soil. Foundation beams loaded by forces and couples at the midspan illustrate accuracy and convergence properties of the proposed formulation

Decay length of end effects in orthotropic laminates

--

Interior solution for anisotropic strips by polynomial series

Usually, the solution of two-dimensional problems for long rectangular strips is represented by double series expansions of Airy stress function in powers of axial and transverse coordinates. Following this way, the computation of the coefficients becomes rather involved if the degree of the polynomial load prescribed on the long sides increases. For isotropic strips, in a previous authors paper a different representation of solution is described, where the series expansion of Airy stress function is obtained in terms of polynomials of the transverse coordinate multiplying the functions which represent the top and bottom loading. In this case, the first term of the series represents the classical beam theory, and the next terms are corrections involving higher derivatives of loading function. In the present paper, homogeneous anisotropic strips subject to any given continuous distribution of both normal and shear loads are considered. The interior problem is solved by means of a polynomial expansion for the Airy stress function. The polynomial functions defined in transverse direction are determined recursively and those varying along the strip length are obtained in terms of loading functions. Explicit formulas for displacement components are also given. This exact elasticity solution is finally used to derive the set of shear correction factors and to establish the range of validity of Timoshenko-like beam theories

Grouted sleeve connections used in precast reinforced concrete construction - Experimental investigation of a column-to-column joint

The results of an experimental campaign concerning full-scale tests on precast reinforced concrete column-to-column connections made with grouted sleeve splices are presented. The precast column units had a square cross-section with the side of 500 mm. Eight 20 mm-diameter bars protruding from one unit were grouted into corrugated steel sleeves encased in the other unit. The column-to-column connections were subjected to four monotonic tests (axial tension, bending with and without axial compression, and shear) and to one cyclic bending test. In the tension test failure took place far from the interface between the precast units and highlighted the effectiveness of the stress transfer along the splice region. In all other tests, damage developed at the interface between the two units. In the bending tests with and without axial compression significant over-strengths with respect to design resistances computed for equally-reinforced monolithic members were attained. Because of the reduced thickness of the interface between the precast units, the rotation that concentrated at the interface led to a moderate reduction of the global bending stiffness. In the shear test the pure shear capacity of the bars crossing the joint was achieved. The cyclic bending test showed a ductile and stable hysteretic behavior of the connection