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Archaeological buried structures have received less attention than aboveground historical structures, which seems evident given the visual impact of the latter. Archaeological structures present specific issues related to stability during excavation and after being exposed. This paper addresses a UNESCO world heritage site in Honduras (Copan), which has about 4 km of tunnels in a complex organization that were dug, in the last 100 years, for the purpose of investigation of buried structures under a temple complex. The objective of this work is to assess the safety of the tunnels, helping on the decision of back-filling the tunnels, adding new masonry linings and allowing access in current conditions (possibly with measures to avoid water infiltration). First, the long network of tunnels was categorized into different sections either in an earthen fill only or in presence of a masonry lining. Then, the stability of these sections was discussed as a function of the increase of soil saturation. It was found that unlined tunnels safety is likely to be compromised for a saturation higher than 70%, whereas lined tunnels do not fail when the soil becomes fully saturated, as far as drainage is ensured. Finally, this work allowed to issue recommendations on actions related to the site.
F. Pires; E. Bilotta; A. Flora; P. B. Lourenço. Assessment of Excavated Tunnels Stability in the Maya Archeological Area of Copán, Honduras. International Journal of Architectural Heritage 2021, 1 -19.
AMA StyleF. Pires, E. Bilotta, A. Flora, P. B. Lourenço. Assessment of Excavated Tunnels Stability in the Maya Archeological Area of Copán, Honduras. International Journal of Architectural Heritage. 2021; ():1-19.
Chicago/Turabian StyleF. Pires; E. Bilotta; A. Flora; P. B. Lourenço. 2021. "Assessment of Excavated Tunnels Stability in the Maya Archeological Area of Copán, Honduras." International Journal of Architectural Heritage , no. : 1-19.
Filomena De Silva; Stefania Fabozzi; Nikolaos Nikitas; Emilio Bilotta; Raul Fuentes. Seismic vulnerability of circular tunnels in sand. Géotechnique 2021, 1 -15.
AMA StyleFilomena De Silva, Stefania Fabozzi, Nikolaos Nikitas, Emilio Bilotta, Raul Fuentes. Seismic vulnerability of circular tunnels in sand. Géotechnique. 2021; ():1-15.
Chicago/Turabian StyleFilomena De Silva; Stefania Fabozzi; Nikolaos Nikitas; Emilio Bilotta; Raul Fuentes. 2021. "Seismic vulnerability of circular tunnels in sand." Géotechnique , no. : 1-15.
The atrium-style station is one of the favourite choices in underground railway systems, as it can provide a larger and clearer space for passengers and commercial clients at the hall level of the station. With such style, as hall slabs are replaced with flat-beams, the station's capabilities to withstand lateral action like seismic action become one of the main concerns. Shaking table tests were conducted to investigate the dynamic response of soil-structure interaction of atrium-style station model under harmonic excitations covering the full frequency range, with comparison to free-field tests. The experimental results confirm that the influence of the structure on the dynamic response of the ground surface begins when the frequency of input motions is greater than 10 Hz. The predominant frequencies of the ground corresponding to the second and third modes both show an increase of 10% from the FF model to the SS model due to the presence of an atrium-style metro station. For atrium-style station: (i) the discontinuous structural elements such as beams and columns are more severely strained than the continuous ones like slabs and side walls, (ii) the peak dynamic soil normal stresses along the side wall follow an approximate L-shaped distribution and the maximum stress occurs at the side wall bottom, and (iii) the spectral characteristics of both dynamic structural strain and dynamic soil normal stress reflect the amplification function of the ground.
Zhiming Zhang; Emilio Bilotta; Yong Yuan; Huiling Zhao. Experiments of an atrium-style metro station under harmonic excitation. Tunnelling and Underground Space Technology 2020, 103, 103463 .
AMA StyleZhiming Zhang, Emilio Bilotta, Yong Yuan, Huiling Zhao. Experiments of an atrium-style metro station under harmonic excitation. Tunnelling and Underground Space Technology. 2020; 103 ():103463.
Chicago/Turabian StyleZhiming Zhang; Emilio Bilotta; Yong Yuan; Huiling Zhao. 2020. "Experiments of an atrium-style metro station under harmonic excitation." Tunnelling and Underground Space Technology 103, no. : 103463.
Large magnitude earthquakes have historically caused devastating damage to engineered structures as a result of permanent ground deformations induced by soil liquefaction (e.g. 1964 Niigata earthquake, 1995 Kobe earthquake, 2010–2011 Christchurch earthquakes). A relevant amount of such damages is directly connected to liquefaction induced lateral spreading. This paper deals with the capacity of concrete framed structures with shallow foundations to handle lateral spreading demands. A simplified force–displacement compatible model was developed to capture the loads on the shallow foundations and estimate the performance of the building. The key parameters of foundation embedment, foundation width and shear length of the pillar, as well as soil friction angle were identified as having a strong influence on the expected performance. The developed model was used to develop probabilistic fragility curves for a class of buildings representing two to five storeys reinforced concrete buildings. Field measurements from existing literature of the liquefaction induced lateral displacement demand from the the September 4, 2010 (Mw 7.1) and the February 22, 2011 (Mw 6.2) Canterbury (New Zealand) earthquakes along the Avon River were probabilistically quantified in relation to the distance from the river. Finally, the displacement demand and fragility curves were used to estimate the probability of exceeding the considered limit states as a function of the distance from the river.
Fausto Somma; Maxim Millen; Emilio Bilotta; Alessandro Flora; Antonio Viana Da Fonseca. Vulnerability assessment of RC buildings to lateral spreading. Bulletin of Earthquake Engineering 2020, 18, 3629 -3657.
AMA StyleFausto Somma, Maxim Millen, Emilio Bilotta, Alessandro Flora, Antonio Viana Da Fonseca. Vulnerability assessment of RC buildings to lateral spreading. Bulletin of Earthquake Engineering. 2020; 18 (8):3629-3657.
Chicago/Turabian StyleFausto Somma; Maxim Millen; Emilio Bilotta; Alessandro Flora; Antonio Viana Da Fonseca. 2020. "Vulnerability assessment of RC buildings to lateral spreading." Bulletin of Earthquake Engineering 18, no. 8: 3629-3657.
This paper proposes a procedure for the calibration of a simplified pore water pressure model implemented in 1D effective stress dynamic analyses. The calibration procedure is based on the cyclic strength of the soils as quantified using empirical correlations with in-situ tests, CPT and SPT. Specific relationships have been directly defined among the parameters of the pore water pressure model and the results of in-situ tests. All the steps for the definition of these relationships are described in detail. The proposed calibration procedure has been used to simulate the seismic response of two well-documented reclaimed sites where widespread liquefaction occurred: Port Island, in Kobe (Japan) and Treasure Island in California (US), struck by the 1995 Kobe and the 1989 Loma Prieta earthquakes, respectively. The results of the analyses have been compared to the actual site response as recorded by downhole acceleration arrays, showing that the proposed approach leads to a good estimate of the site response. Guidelines for calibration of the proposed model are finally provided, and the advantages and limitations of its use are discussed in detail.
Anna Chiaradonna; Alessandro Flora; Anna D'Onofrio; Emilio Bilotta. A pore water pressure model calibration based on in-situ test results. Soils and Foundations 2020, 60, 327 -341.
AMA StyleAnna Chiaradonna, Alessandro Flora, Anna D'Onofrio, Emilio Bilotta. A pore water pressure model calibration based on in-situ test results. Soils and Foundations. 2020; 60 (2):327-341.
Chicago/Turabian StyleAnna Chiaradonna; Alessandro Flora; Anna D'Onofrio; Emilio Bilotta. 2020. "A pore water pressure model calibration based on in-situ test results." Soils and Foundations 60, no. 2: 327-341.
Analytical solutions are deduced for seismic responses of shaft-tunnel junction under longitudinal excitations. The influence of the tunnel is incorporated by introducing terms of shaft-tunnel and soil-tunnel interactions into equations originally developed for rigid caissons. The shaft is simplified into a rigid body. The tunnel is represented by a continuous beam perpendicularly fixed onto the shaft. Firstly, solutions for displacements of the shaft are given. Then, solutions for the three major internal forces of the tunnel are proposed. Validity of the proposed solutions is examined by finite element method in respect of the shaft and the tunnel separately. The comparisons confirm that the proposed solutions could successfully predict the displacements of the shaft and the three major internal forces of the tunnel at the vicinity of the shaft-tunnel junction. However, they become less accurate with increasing distance to the shaft. Interactions among the shaft, the tunnel, and the soil are discussed based on the proposed solutions. A special emphasis is placed on the mutual influences between the shaft and the tunnel. Displacements of the shaft, especially the rotational displacements, are likely to decrease under longitudinal excitations when connected to tunnels. Shaft-soil relative displacement and soil-tunnel relative stiffness are the two key factors affecting the seismic responses of the tunnel. The former determines the amplitudes of the internal forces, while the latter governs how the internal forces distribute along the tunnel axis. A conceptual aseismic measure is studied by setting a pin joint at the shaft-tunnel junction. Theoretically, it could eliminate the influence imposed on the tunnel by the rotational displacement of the shaft.
Jinghua Zhang; Yong Yuan; Emilio Bilotta; Haitao Yu. Analytical solutions for seismic responses of shaft-tunnel junction under longitudinal excitations. Soil Dynamics and Earthquake Engineering 2020, 131, 106033 .
AMA StyleJinghua Zhang, Yong Yuan, Emilio Bilotta, Haitao Yu. Analytical solutions for seismic responses of shaft-tunnel junction under longitudinal excitations. Soil Dynamics and Earthquake Engineering. 2020; 131 ():106033.
Chicago/Turabian StyleJinghua Zhang; Yong Yuan; Emilio Bilotta; Haitao Yu. 2020. "Analytical solutions for seismic responses of shaft-tunnel junction under longitudinal excitations." Soil Dynamics and Earthquake Engineering 131, no. : 106033.
This paper presents experimental assessment of the effect of the ratio of vertical to horizontal peak ground acceleration (RVH) on underground metro station. An atrium-style metro station embedded in artificial soil subjected to earthquake loading is examined through shaking table tests. The experimental results for three different RVH, including soil acceleration, soil-structure acceleration difference, dynamic soil normal stress (DSNS), and structural dynamic strain, are presented and the results are compared with the case of horizontal-only excitation. It is found that for an atrium-style metro station, the differences in horizontal acceleration amplitude between the structure and the adjacent soil rise with increasing RVH, which are different at different depths. The most significant differences occur at the depth of the ceiling slab. It is also observed that both the amplitude and distribution of peak DSNS have obvious differences between the left and right side walls at all levels. It is therefore concluded that the RVH has a significant influence on dynamic soil-structure interaction. It is believed that under extreme earthquake loading, such as near fault zones, RVH is a parameter of paramount importance and should be accounted for in the seismic analyses and seismic performance assessments of underground structures, especially for those with zero or near-zero buried depth, such as atrium-style metro stations.
Zhiming Zhang; Emilio Bilotta; Yong Yuan; Haitao Yu; Huiling Zhao. Experimental Assessment of the Effect of Vertical Earthquake Motion on Underground Metro Station. Applied Sciences 2019, 9, 5182 .
AMA StyleZhiming Zhang, Emilio Bilotta, Yong Yuan, Haitao Yu, Huiling Zhao. Experimental Assessment of the Effect of Vertical Earthquake Motion on Underground Metro Station. Applied Sciences. 2019; 9 (23):5182.
Chicago/Turabian StyleZhiming Zhang; Emilio Bilotta; Yong Yuan; Haitao Yu; Huiling Zhao. 2019. "Experimental Assessment of the Effect of Vertical Earthquake Motion on Underground Metro Station." Applied Sciences 9, no. 23: 5182.
Drainage is one of the most popular protecting measures to mitigate ground liquefaction. Deploying the drains horizontally may be convenient where conventional vertical ones cannot be used, like beneath existing structures. The spacing among drains must be designed to limit the pore pressure build-up during shaking. The usual assumptions of radial consolidation around vertical drains, stemming from the assumption of an infinite number of drains, may not be appropriate for horizontal ones, since the latter are generally arranged in few rows at a shallow depth, especially if drainage at the ground level is possible as well. Hence, existing solutions for vertical “earthquake” drains have been modified in this work to take into account such different geometrical features. The resulting solution has been validated against numerical and experimental sets of data. Charts covering a wide range of geometrical layouts, soil properties, and seismic actions are finally proposed. They can be used to design the drain spacing that is needed so as not to exceed the target value of excess pore pressure in the ground.
Gianluca Fasano; Domenico De Sarno; Emilio Bilotta; Alessandro Flora. Design of horizontal drains for the mitigation of liquefaction risk. Soils and Foundations 2019, 59, 1537 -1551.
AMA StyleGianluca Fasano, Domenico De Sarno, Emilio Bilotta, Alessandro Flora. Design of horizontal drains for the mitigation of liquefaction risk. Soils and Foundations. 2019; 59 (5):1537-1551.
Chicago/Turabian StyleGianluca Fasano; Domenico De Sarno; Emilio Bilotta; Alessandro Flora. 2019. "Design of horizontal drains for the mitigation of liquefaction risk." Soils and Foundations 59, no. 5: 1537-1551.
This paper proposes an analytical solution for dynamic responses of the vertical shaft in a shaft-tunnel junction under transverse loads. The assumption is that the shaft could be regarded as a rigid body under certain circumstances. Based on that premise, equations originally developed for rigid caissons are incorporated with terms of shaft-tunnel and soil-tunnel interactions. Two specific dynamic scenarios are considered. The first one is when the shaft is subject to transverse dynamic loads above the ground surface. The second one is when the shaft-tunnel junction is under transverse seismic excitations. Validity of the proposed solution is examined in both scenarios by finite element method. Then, the proposed solution is used to evaluate influence of the tunnel. In the first scenario, the tunnel has a major influence on dynamic responses of the shaft. Displacements of the shaft are likely to be reduced because the tunnel adds to the stiffness matrix. Yet, in the second scenario, influence of the tunnel is minor enough to be neglected. Seismic responses of the shaft are approximately the same with or without the tunnel.
Jinghua Zhang; Yong Yuan; Emilio Bilotta; Bu Zhang; Haitao Yu. Analytical solution for dynamic responses of the vertical shaft in a shaft-tunnel junction under transverse loads. Soil Dynamics and Earthquake Engineering 2019, 126, 105779 .
AMA StyleJinghua Zhang, Yong Yuan, Emilio Bilotta, Bu Zhang, Haitao Yu. Analytical solution for dynamic responses of the vertical shaft in a shaft-tunnel junction under transverse loads. Soil Dynamics and Earthquake Engineering. 2019; 126 ():105779.
Chicago/Turabian StyleJinghua Zhang; Yong Yuan; Emilio Bilotta; Bu Zhang; Haitao Yu. 2019. "Analytical solution for dynamic responses of the vertical shaft in a shaft-tunnel junction under transverse loads." Soil Dynamics and Earthquake Engineering 126, no. : 105779.
This paper presents a simplified procedure for the evaluation of the free-field consolidation settlement induced by liquefaction, using the results of 1D site response analysis in effective stress and a simplified approach based on empirical chart. The excess pore water pressures induced by the seismic action are generated by both a simple stress-based model implemented on a non-linear dynamic analysis and a simplified relationship between the safety factor against liquefaction and the excess pore pressure. The post-cyclic settlement is finally calculated on the obtained distribution of excess pore water pressure along the soil column. The proposed method has been used to estimate the consolidation settlements in a centrifuge test and in well-documented case histories of widespread liquefaction: Treasure Island and Marina District after the 1989 Loma Prieta earthquake. The results have been compared to the measured settlements and to the values obtained by previous studies. It is shown that the proposed approach leads to a much more accurate estimate of the post-liquefaction consolidation settlement, with just a little increase of the calculation effort.
Anna Chiaradonna; Anna D’Onofrio; Emilio Bilotta. Assessment of post-liquefaction consolidation settlement. Bulletin of Earthquake Engineering 2019, 17, 5825 -5848.
AMA StyleAnna Chiaradonna, Anna D’Onofrio, Emilio Bilotta. Assessment of post-liquefaction consolidation settlement. Bulletin of Earthquake Engineering. 2019; 17 (11):5825-5848.
Chicago/Turabian StyleAnna Chiaradonna; Anna D’Onofrio; Emilio Bilotta. 2019. "Assessment of post-liquefaction consolidation settlement." Bulletin of Earthquake Engineering 17, no. 11: 5825-5848.
The seismic performance of underground tunnels is affected by some significant factors mostly depending on the seismic loading conditions, the tunnel structure in interaction with the surrounding soil and the three dimensional geometry of the tunnel and the soil stratigraphy. The paper addresses the problem of underground tunnels when subjected to asynchronous seismic shaking along the axis in comparison with the synchronous case that is usually considered in the tunnels design. The study also includes the effect of the curved shape of the tunnel axis, the sudden change of dynamic impedance along its axis, the direction of the propagating wave and the effect of the initial state of stress induced by the excavation process. A finite element model able to catch the main deformation patterns of a tunnel subjected to non-uniform seismic load, coupling the axial and longitudinal deformations has been defined in Plaxis 3D. The numerical model has been first validated with a simplified benchmark case where the soil behaves elastically, and afterwards on the real case of the Metro Line 6 of Naples, assuming a more sophisticated constitutive model for the soil. The results of the 3D full dynamic analyses show the effect of the ground motion asynchronism on the distributions of internal forces in the tunnel lining.
S. Fabozzi; Emilio Bilotta; H. Yu; Y. Yuan. Effects of the asynchronism of ground motion on the longitudinal behaviour of a circular tunnel. Tunnelling and Underground Space Technology 2018, 82, 529 -541.
AMA StyleS. Fabozzi, Emilio Bilotta, H. Yu, Y. Yuan. Effects of the asynchronism of ground motion on the longitudinal behaviour of a circular tunnel. Tunnelling and Underground Space Technology. 2018; 82 ():529-541.
Chicago/Turabian StyleS. Fabozzi; Emilio Bilotta; H. Yu; Y. Yuan. 2018. "Effects of the asynchronism of ground motion on the longitudinal behaviour of a circular tunnel." Tunnelling and Underground Space Technology 82, no. : 529-541.
Linear infrastructures have strategic importance and impact on the social and economic conditions of many countries, hence the seismic risk management of existing and new designed ones is a crucial issue in earthquake-prone areas. High-speed and high capacity railways are an example of infrastructures that assume increasing importance in developed countries, since they permit rapid transit of people and freight. Due to the seismicity of the country, the case of the high-speed railways Italian network appears suitable for assessing the feasibility of a loss-driven earthquake early-warning system based on the real-time estimation of the expected damage probability and lead-time. Among the several subsystems that compose the network, the paper focuses on tunnels, since they are largely present along the route of the existing high-speed lines and of the new ones currently under design. This work describes a procedure that exploits the disaggregation of the seismic hazard to define sets of virtual seismic sources potentially affecting railway's tunnels. Hence, the probability of seismic damage to tunnel structures and the time available for implementing real-time mitigation procedures can be calculated. Such a procedure is applied to two tunnels of the high-speed system with different structural layout. The procedure suggests that for the considered tunnels the best option for undertaking seismic risk mitigation measures would be an on-site threshold–based early-warning system. However, the foreseen probability of structural damage to the tunnel lining is low in both cases. The proposed methodology can be easily generalized to different targets to design the optimal configuration of an earthquake early warning system, and applied to control, manage and maintain the tunnel structures along the high-speed railway network.
S. Fabozzi; Emilio Bilotta; M. Picozzi; A. Zollo. Feasibility study of a loss-driven earthquake early warning and rapid response systems for tunnels of the Italian high-speed railway network. Soil Dynamics and Earthquake Engineering 2018, 112, 232 -242.
AMA StyleS. Fabozzi, Emilio Bilotta, M. Picozzi, A. Zollo. Feasibility study of a loss-driven earthquake early warning and rapid response systems for tunnels of the Italian high-speed railway network. Soil Dynamics and Earthquake Engineering. 2018; 112 ():232-242.
Chicago/Turabian StyleS. Fabozzi; Emilio Bilotta; M. Picozzi; A. Zollo. 2018. "Feasibility study of a loss-driven earthquake early warning and rapid response systems for tunnels of the Italian high-speed railway network." Soil Dynamics and Earthquake Engineering 112, no. : 232-242.
The paper proposes a three-dimensional numerical model able to catch the main deformation patterns of the soil and of an underground tunnel structure subjected to non-uniform seismic shaking. The proposed 3D FE model for instance, investigate the effect of the non-uniform seismic loading condition due to the wave passage along the longitudinal axis of a tunnel and a comparison between the uniform and non-uniform case is proposed both in terms of free field and soil-structure interaction analysis. The numerical results show the non-negligible effect of wave passage on the tunnel structure compared with the uniform case. The dynamic increment of the transversal component of the internal tunnel forces is higher if the asynchronism is considered, in function of the shear waves velocity of propagation in the bedrock. In addition, longitudinal components of the internal forces arise on tunnel, i.e. longitudinal normal force, horizontal bending and shear force acting in the horizontal plane along the structure.
Stefania Fabozzi; Emilio Bilotta; Haitao Yu; Yong Yuan. Effect of Travelling Waves on Tunnels in Soft Soil. Proceedings of the 28th International Symposium on Mine Planning and Equipment Selection - MPES 2019 2018, 324 -327.
AMA StyleStefania Fabozzi, Emilio Bilotta, Haitao Yu, Yong Yuan. Effect of Travelling Waves on Tunnels in Soft Soil. Proceedings of the 28th International Symposium on Mine Planning and Equipment Selection - MPES 2019. 2018; ():324-327.
Chicago/Turabian StyleStefania Fabozzi; Emilio Bilotta; Haitao Yu; Yong Yuan. 2018. "Effect of Travelling Waves on Tunnels in Soft Soil." Proceedings of the 28th International Symposium on Mine Planning and Equipment Selection - MPES 2019 , no. : 324-327.
The recent earthquakes that hit Italy have shown that the built heritage is at risk not only because of inertial and kinematic stresses directly induced on the structure by shaking, but also because of possible soil liquefaction phenomena. The techniques generally used to mitigate the soil liquefaction susceptibility in the case of new constructions (vibro-compaction, dynamic compaction, etc.), are generally not suitable for existing buildings. Within a large European project (LIQUEFACT), the University of Napoli is studying innovative soil improvement techniques suitable for the mitigation of the soil liquefaction risk in densely urbanized areas. In this paper, the addition of fine content (laponite) is experimentally studied by means of different preliminary laboratory tests with the main goal to verify the injectability and effectiveness of the selected mixtures against liquefaction. The applicability of this technique has been verified by means of viscosity and permeability tests, while its effectiveness has been analyzed via cyclic triaxial tests. Experimental results show that the addition of an additive (SPP) to delay the mixture gelling time is necessary to assure the injectability of the tested laponite mixtures. The addition of fine content reduces the mobility of grains and modifies the pore pressure building up during cycling loads, leading to an increase of soil liquefaction resistance.
Lucia Mele; Alessandro Flora; Stefania Lirer; Anna D’Onofrio; Emilio Bilotta. Experimental Study of the Injectability and Effectiveness of Laponite Mixtures as Liquefaction Mitigation Technique. Geotechnical Earthquake Engineering and Soil Dynamics V 2018, 1 .
AMA StyleLucia Mele, Alessandro Flora, Stefania Lirer, Anna D’Onofrio, Emilio Bilotta. Experimental Study of the Injectability and Effectiveness of Laponite Mixtures as Liquefaction Mitigation Technique. Geotechnical Earthquake Engineering and Soil Dynamics V. 2018; ():1.
Chicago/Turabian StyleLucia Mele; Alessandro Flora; Stefania Lirer; Anna D’Onofrio; Emilio Bilotta. 2018. "Experimental Study of the Injectability and Effectiveness of Laponite Mixtures as Liquefaction Mitigation Technique." Geotechnical Earthquake Engineering and Soil Dynamics V , no. : 1.
The importance of predicting ground deformation in loose, saturated granular soils has been widely recognized for a reliable evaluation of liquefaction damage. A procedure is proposed in this paper for the evaluation of post-cyclic consolidation settlements, as a result of volumetric strains induced by the dissipation of excess pore pressure. A stress-based model is first adopted for generating the excess pore water pressure in 1D free-field conditions, allowing for an effective stress analysis according to a loosely coupled approach. Then, the post-cyclic settlement is simply calculated integrating the vertical strains. To this aim, by considering a well-documented case history in which an extremely small settlement was observed upon seismic excitation, soil stiffness is estimated on the basis of either CPT data or shear stiffness decay curve, to show the effect of modelling hypothesis on the results. Both approaches result into a value of the settlement close to the observed one and much lower than that calculated using a well-established empirical procedure.
Anna Chiaradonna; Emilio Bilotta; Anna D’Onofrio; Alessandro Flora; Francesco Silvestri. A Simplified Procedure for Evaluating Post-Seismic Settlements in Liquefiable Soils. Geotechnical Earthquake Engineering and Soil Dynamics V 2018, 1 .
AMA StyleAnna Chiaradonna, Emilio Bilotta, Anna D’Onofrio, Alessandro Flora, Francesco Silvestri. A Simplified Procedure for Evaluating Post-Seismic Settlements in Liquefiable Soils. Geotechnical Earthquake Engineering and Soil Dynamics V. 2018; ():1.
Chicago/Turabian StyleAnna Chiaradonna; Emilio Bilotta; Anna D’Onofrio; Alessandro Flora; Francesco Silvestri. 2018. "A Simplified Procedure for Evaluating Post-Seismic Settlements in Liquefiable Soils." Geotechnical Earthquake Engineering and Soil Dynamics V , no. : 1.
Stefania Fabozzi; Emilio Bilotta. Numerical study of segmental tunnel lining behavior during mechanized tunneling. Geotechnical Aspects of Underground Construction in Soft Ground 2017, 171 -178.
AMA StyleStefania Fabozzi, Emilio Bilotta. Numerical study of segmental tunnel lining behavior during mechanized tunneling. Geotechnical Aspects of Underground Construction in Soft Ground. 2017; ():171-178.
Chicago/Turabian StyleStefania Fabozzi; Emilio Bilotta. 2017. "Numerical study of segmental tunnel lining behavior during mechanized tunneling." Geotechnical Aspects of Underground Construction in Soft Ground , no. : 171-178.
Underground construction in historic urban environment requires a careful prediction of the expected displacement field to avoid damages or to undertake preventative measures. The empirical method to predict ground movements in greenfield conditions (Peck, 1969; Attwell and Woodman, 1982) is routinely used. A more accurate prediction can be obtained via numerical analysis. A preliminary greenfield 3D FEM model was calibrated to analyse a stretch of a tunnel under construction in Napoli. Subsequently an interaction analysis has been carried out modelling an existing monumental building. Both the geometry of the intersection and the soil layering suggested using a 3D numerical model. The building was modelled as a stiff plate loaded by a uniform surface load. A satisfactory agreement between predictions and measurements was obtained with the interaction analysis.
Emilio Bilotta; Andrea Paolillo; Gianpiero Russo; Stefano Aversa. Displacements induced by tunnelling under a historical building. Tunnelling and Underground Space Technology 2017, 61, 221 -232.
AMA StyleEmilio Bilotta, Andrea Paolillo, Gianpiero Russo, Stefano Aversa. Displacements induced by tunnelling under a historical building. Tunnelling and Underground Space Technology. 2017; 61 ():221-232.
Chicago/Turabian StyleEmilio Bilotta; Andrea Paolillo; Gianpiero Russo; Stefano Aversa. 2017. "Displacements induced by tunnelling under a historical building." Tunnelling and Underground Space Technology 61, no. : 221-232.
An approach to mitigate the seismic risk of existing structures by means of the creation of a continuous thin layer of grouted soil at a convenient depth is presented. A parametric numerical analysis is reported using different constitutive models with reference to two geometrical schemes. It is shown that if the grouted layer has a stiffness significantly lower than that of the surrounding soil, it may be effective in reducing the seismic demand. In the parametric analyses, the positive role of yielding is also observed, which indicates that the barrier is more effective with larger input amplitudes.
A. Flora; D. Lombardi; V. Nappa; E. Bilotta. Numerical Analyses of the Effectiveness of Soft Barriers into the Soil for the Mitigation of Seismic Risk. Journal of Earthquake Engineering 2016, 22, 63 -93.
AMA StyleA. Flora, D. Lombardi, V. Nappa, E. Bilotta. Numerical Analyses of the Effectiveness of Soft Barriers into the Soil for the Mitigation of Seismic Risk. Journal of Earthquake Engineering. 2016; 22 (1):63-93.
Chicago/Turabian StyleA. Flora; D. Lombardi; V. Nappa; E. Bilotta. 2016. "Numerical Analyses of the Effectiveness of Soft Barriers into the Soil for the Mitigation of Seismic Risk." Journal of Earthquake Engineering 22, no. 1: 63-93.
The installation of passive structural systems to protect existing buildings from seismic risk is very common, yet it can be expensive and is not always feasible in the case of valuable buildings. It may affect the integrity of structures of artistic or historical relevance in a way that cannot be accepted in the light of the most recent rules of conservation and retrofitting. As an alternative, ground improvement techniques can be used to modify ground properties, in order to mitigate the intensity of shaking at ground level. This paper focuses on the case of a V-shaped barrier that may be formed by assembling inclined and partially overlapped columns of artificially softened soil to isolate a mass in the ground. The response of a single degree of freedom founded within the isolated ground mass is then studied by way of finite-element analyses and the results are commented on.
Valeria Nappa; Emilio Bilotta; Alessandro Flora. Isolated soil mass at foundation for mitigating seismic risk. Geotechnical Research 2016, 3, 31 -39.
AMA StyleValeria Nappa, Emilio Bilotta, Alessandro Flora. Isolated soil mass at foundation for mitigating seismic risk. Geotechnical Research. 2016; 3 (2):31-39.
Chicago/Turabian StyleValeria Nappa; Emilio Bilotta; Alessandro Flora. 2016. "Isolated soil mass at foundation for mitigating seismic risk." Geotechnical Research 3, no. 2: 31-39.
A number of constitutive models are nowadays implemented in numerical codes which simulate the stress–strain behaviour of soil from very small to large strain. In this paper, the mechanical behaviour of Leighton Buzzard sand (grade E), used worldwide for physical modelling, has been thoroughly characterized by laboratory testing along several stress paths. Tests were aimed at calibrating a constitutive model, that allows considering stiffness nonlinearities in a wide range of strains, in the framework of isotropically hardening plasticity. As a validation, the results of dynamic centrifuge tests on a layer of the same sand were compared with finite element predictions
Giovanni Lanzano; Ciro Visone; Emilio Bilotta; Filippo Santucci De Magistris. Experimental Assessment of the Stress–Strain Behaviour of Leighton Buzzard Sand for the Calibration of a Constitutive Model. Geotechnical and Geological Engineering 2016, 34, 991 -1012.
AMA StyleGiovanni Lanzano, Ciro Visone, Emilio Bilotta, Filippo Santucci De Magistris. Experimental Assessment of the Stress–Strain Behaviour of Leighton Buzzard Sand for the Calibration of a Constitutive Model. Geotechnical and Geological Engineering. 2016; 34 (4):991-1012.
Chicago/Turabian StyleGiovanni Lanzano; Ciro Visone; Emilio Bilotta; Filippo Santucci De Magistris. 2016. "Experimental Assessment of the Stress–Strain Behaviour of Leighton Buzzard Sand for the Calibration of a Constitutive Model." Geotechnical and Geological Engineering 34, no. 4: 991-1012.