Strong Ground Motion in the Epicentral Region of the M\u3csub\u3ew\u3c/sub\u3e 6.3, Apr 6 2009, L’Aquila Earthquake, Italy

In the night of Apr 6 2009, a Mw 6.3 earthquake struck the Abruzzi region and the whole Central Italy, causing about 300 deaths and vast destructions in the town of L\u27Aquila, one of the largest urban centres in Central Italy, and its surroundings. As most destructive earthquakes in the Italian Central and Southern Apennines mountain chain, this was caused by a normal fault rupture, the epicenter of which was estimated at less than 5 km from the center of L\u27Aquila. Several 3-components digital strong motion instruments were installed around L\u27Aquila at few km distance from the epicenter: 3 of them recorded the earthquake along a transept crossing the Aterno river valley, while two of them are located in the town centre. The near-fault conditions, the complex geological setting – L\u27Aquila lies on a fluvial terrace, consisting of calcareous breccias and conglomerates, lying on the top of lacustrine silty sediments – and the availability of several very good quality near-fault records, make this earthquake an important benchmark that provided an impressive and instructive picture of strong ground motion in the epicentral region of a normal fault earthquake. This paper illustrates some of the most interesting features of the L\u27Aquila earthquake near-fault dataset, including (i) peak values and spectral ordinates, together with their relationship with respect to some of the most up-to-date ground motion prediction equations, (ii) long period components, (iii) vertical vs horizontal ground motion. Finally, since the L\u27Aquila shallow subsoil is characterized by frequent natural buried cavities of karst origin, we briefly investigate their potential role on the seismic response

Investigation of Seismic Soil-Footing Interaction by Large Scale Cyclic Tests and Analytical Models

Recent experimental and analytical research on seismic behavior of shallow foundations is illustrated. The most significant results on the seismic bearing capacity of footings with pseudo-static approaches are reviewed first, including an analytical formula recently proposed for the new version of the “seismic” Eurocode 8. Afterwards, we present the salient experimental results of large-scale cyclic tests of a shallow foundation model (1m x 1m in plan) resting on a large volume of sand, with relative densities 45% and 85%, discussing them in detail. Under earthquake-like cyclic loading, with peak values close to the pseudo-static failure limit, significant permanent settlement and rocking were observed, approaching serviceability limit states in low-density soil conditions. A series of displacement cycles of increasing amplitude was subsequently applied, up to the ultimate capacity of the soil-foundation system. Although the experimental cyclic bearing capacity is much higher than that predicted by pseudo-static approaches, this advantage is offset by the occurrence of large permanent deformations that may lead the structure to collapse. Finally, a recent theoretical method for performing simple nonlinear dynamic soil-structure interaction analyses is reviewed, and applied to estimating the reduction of response spectrum ordinates in strong earthquakes. Reductions up to 30%-50% were found for spectral accelerations exceeding 0.4g

Investigation of Seismic Soil-Footing Interaction by Large Scale Tests and Analytical Models

Recent experimental and analytical research on seismic behavior of shallow foundations is illustrated. The most significant results on the seismic bearing capacity of footings with pseudo-static approaches are reviewed first, including an analytical formula recently proposed for the new version of the “seismic” Eurocode 8. Afterwards, we present the salient experimental results of large-scale cyclic tests of a shallow foundation model (1m x 1m in plan) resting on a large volume of sand, with relative densities 45% and 85%, discussing them in detail. Under earthquake-like cyclic loading, with peak values close to the pseudo-static failure limit, significant permanent settlement and rocking were observed, approaching serviceability limit states in low-density soil conditions. A series of displacement cycles of increasing amplitude was subsequently applied, up to the ultimate capacity of the soil-foundation system. Although the experimental cyclic bearing capacity is much higher than that predicted by pseudo-static approaches, this advantage is offset by the occurrence of large permanent deformations that may lead the structure to collapse. Finally, a recent theoretical method for performing simple nonlinear dynamic soil-structure interaction analyses is reviewed, and applied to estimating the reduction of response spectrum ordinates in strong earthquakes. Reductions up to 30%-50% were found for spectral accelerations exceeding 0.4g

GIS-Based Identification of Topographic Sites in Italy with Significant Ground Motion Amplification Effects

Surface topography can significantly affect earthquake ground motions, as suggested by many examples of unexpected damage suffered by buildings located on the top of hills, on ridges or along slopes. European and Italian seismic codes suggest topographic aggravation factors in the 1 – 1.4 range to be applied to seismic actions, depending not only on simple morphologic parameters (average slope angle, width and height of the relief) but also on the type of relief (isolated cliff or ridge) and on the location of the site relative to the relief. Furthermore, strongly irregular topographies should be dealt with by a specific study. To provide a practical tool for the identification of critical topographic sites, analyses of high resolution digital elevation models (DEM), with the support of Geographic Information Systems (GIS), are presented in this paper. Simple GIS functions are used to classify critical ranges of inclination, while the identification of valleys and ridges requires more complex procedures. A comparison of different methods for their identification is presented in this work, aiming at finding the most suitable ones for seismic microzonation analyses. Once the critical conditions are synthesized into GIS layers, their proximity to inhabited centres or strategic structures are checked. The resulting maps can be used for topography-related seismic risk assessment at large scale. We present two examples of application of this procedure, with particular attention to the small historical centres located on the Apennine mountains in Central and Southern Italy

Hydrostructural setting of Riardo Plain: effects on Ferrarelle mineral water type

The exploitation of groundwater resources must always keep in account the geology and hydrogeological settings of the catchment basin for the sustainability of withdrawals, in order not to overexploit the aquifer. Especially, in the case of mineral water extraction, even more attention should be paid to understand what are the water-rock-gases interaction mechanisms, which allow obtaining a specific water chemistry. The case of Ferrarelle mineral water (western sector of Riardo Plain, Caserta) is particularly complex. Through the acquisition of a great amount of former geological and hydrogeological data and by new hydrogeological surveys, it has been possible to distinguish the aquifer levels, distinguishing four circulations over the Roccamonfina Volcano and in the Riardo Plain. The presence of volcanic and volcaniclastic deposits deriving from the Roccamonfina Volcano which cover a highlytectonized carbonate bedrock, allows the formation of two aquifers in hydraulic continuity. This mixing between the two aquifers allows, with the ascent of deep CO2 through faults in the carbonate bedrock, the formation of the typical chemical composition of the mineral water Ferrarelle. In the eastern sector of the plain, it is possible to distinguish the volcanic aquifer from the carbonate one, probably due to the presence of low permeability deposits

Correction to: Deep reinforcement learning for multi-objective placement of virtual machines in cloud datacenters

Page 2: Column 2, lines 2-4, previously read: "Specifically, we consider a decision maker that, after a proper training, is able to select the most suitable heuristic for compute the placement for each VM requested by end users"

APEnet+: a 3D toroidal network enabling Petaflops scale Lattice QCD simulations on commodity clusters

Many scientific computations need multi-node parallelism for matching up both space (memory) and time (speed) ever-increasing requirements. The use of GPUs as accelerators introduces yet another level of complexity for the programmer and may potentially result in large overheads due to the complex memory hierarchy. Additionally, top-notch problems may easily employ more than a Petaflops of sustained computing power, requiring thousands of GPUs orchestrated with some parallel programming model. Here we describe APEnet+, the new generation of our interconnect, which scales up to tens of thousands of nodes with linear cost, thus improving the price/performance ratio on large clusters. The project target is the development of the Apelink+ host adapter featuring a low latency, high bandwidth direct network, state-of-the-art wire speeds on the links and a PCIe X8 gen2 host interface. It features hardware support for the RDMA programming model and experimental acceleration of GPU networking. A Linux kernel driver, a set of low-level RDMA APIs and an OpenMPI library driver are available, allowing for painless porting of standard applications. Finally, we give an insight of future work and intended developments

Agent-Based Enhanced Workflow in Manufacturing Information Systems: the MAKE-IT Approach

Manufacturing is one of the main fields of application of software agent technology. In this respect, several current research projects focus on workflow management, with the aim of an integration and coordination among plant and business activities. In section I, the state of the art is presented, relevant to software agents and to the technologies currently adopted in the exploitation of agents in manufacturing information systems. In section II, the possibility of developing real-time agents at the shop floor level is investigated. In section III, the MAKE-IT (Manufacturing Agents in a Knowledgebased Environment driven by Internet Technologies) approach to agent-based enhanced workflow in manufacturing information system is presented. Finally section IV presents our conclusions