Person | TU Delft Repository

A. Prosperi

View Orcid Profile

View Pure Profile

Authored

8 records found

Shape matters

Influence of varying settlement profiles due to multicausal subsidence when modelling damage in a masonry façade

Conference paper - A. Prosperi, M. Longo, Paul A. Korswagen, M. Korff, M. Korff, J.G. Rots

This paper demonstrates the use of non-linear finite element modelling to investigate the response of structures subjected to different shapes of subsidence-related ground settlements. The approach is presented with reference to a two-storey unreinforced masonry façade resting on ...

Empirical fragility and ROC curves for masonry buildings subjected to settlements

Journal article - A. Prosperi, Paul A. Korswagen, M. Korff, H.R. Schipper, J.G. Rots

In the Netherlands, the potential damage to the building stock due to subsidence phenomena has recently received increased awareness. However, evaluating and predicting damage to buildings in subsiding areas is a complex task that requires associating the vulnerability of exposed structures with the intensity of the subsidence hazard. Considering the widespread presence of subsidence-related damage to the built heritage, the focus of this study is to provide empirical-based insights to assess and forecast subsidence damage to masonry buildings. A rich dataset with manual levelling measurements was collected comprising 386 surveyed masonry buildings, mainly low-rise (terraced) houses built before 1950. Of the total set of buildings, 122 cases rest on shallow foundations and 264 on piled foundations. For each building, the recorded damage is related to the settlement, calculated from the bed-joint levelling measurements, using four different intensity parameters, namely differential settlement, rotation, relative rotation and deflection ratio. These four parameters are appraised in their capacity to effectively predict the intensity of the damage. The Receiver Operating Characteristic (ROC) method is used to evaluate the relative efficacy of the selected hazard parameters. The rotation, the relative rotation (angular distortion) and the deflection ratio are observed as the most accurate when predicting the intensity of damage, while the differential settlement appears less accurate. Additionally, the dataset was used to generate empirical fragility curves where the probability of damage is described as a function of the aforementioned parameters. Thresholds were set to distinguish between the light damage and the functional and structural damage state. At a relative rotation of 1/500 masonry buildings on shallow foundations were observed to reach or exceed light damage with a probability of 13%, and functional and structural damage with 5%. The availability of the bed joint levelling measurements made it possible to classify eight recurrent settlement profiles, including both symmetric and asymmetric profiles, associated with both the overall deformation and the rigid rotations of the surveyed buildings.@en

Sensitivity modelling with objective damage assessment of unreinforced masonry façades undergoing different subsidence settlement patterns

Journal article - A. Prosperi, M. Longo, Paul A. Korswagen, M. Korff, M. Korff, J.G. Rots

This study aims to investigate the damage response of unreinforced masonry (URM) façades resting on strip foundations and subjected to ground settlements via numerical models. The models depict the non-linear constitutive behaviour of both the masonry, via smeared cracking, and of the soil-foundation interaction, via nonlinear interface elements. The influence of building features, such as the masonry material, the length over height (L/H) ratio of the geometry, the wall thickness, the number and size of openings and different types of strip foundations (i.e. reinforced concrete and unreinforced) is examined. A sensitivity study additionally investigates the influence of the interface stiffness and its constitutive model. A Gaussian curve is used to replicate the shape of the ground settlements; These simulate the loss of support underneath the foundation due to urban subsidence. Eight settlement shapes are applied in the FE models, including both symmetric and asymmetric profiles, while the angular distortion is used to measure their intensity. A new aspect is that the extent of the induced damage to the façade is assessed objectively using a damage parameter that represents the number, length and width of cracks in a single scalar value. The method distinguishes between the applied settlement profile at the bottom of the interface and the retrieved settlement profile measured on the façade. The analyses indicate that for a value of the angular distortion equal to 2 ‰ (or 1/500), computed from the resulting deformations of the façades, 60% of the models exhibit serviceability damage associated with cracks of about 5 mm width. Accordingly, the limit values available in the literature are observed to be too optimistic and not conservative in relation to the analyses presented in this study. A key outcome is that facades with an L/H smaller or equal to 1 do not exhibit cracks wider than 1 mm. Façades on reinforced concrete foundations were observed to be less susceptible to settlement damage, compared to unreinforced ones.@en

District-scale numerical analysis of settlements related to groundwater lowering in variable soil conditions

Journal article - Dario Peduto, A. Prosperi, A. Prosperi, Gianfranco Nicodemo, M. Korff, M. Korff

This study presents a novel framework in which numerical modelling contributes to the performance of district-scale, subsidence-induced damage assessment in cities where ground settlements affect entire quarters. Therein, the implementation of expeditious procedures offers geotec ...

Accurate and Efficient 2D Modelling of Historical Masonry Buildings Subjected to Settlements in Comparison to 3D Approaches

Conference paper - A. Prosperi, M. Longo, Paul A. Korswagen, M. Korff, M. Korff

This paper presents an improved 2D modelling strategy which aims to represent the behavior of historical unreinforced masonry buildings on shallow foundations subjected to ground settlements. The application is presented with reference to a two-storey building, typical of the Dut ...

Modelling of Damage in Historical Masonry Façades Subjected to a Combination of Ground Settlement and Vibrations

Book chapter - Paul A. Korswagen, M. Longo, A. Prosperi, J.G. Rots, K.C. Terwel

Historical masonry façades are sensitive to various damaging processes. A recent study, looking at the initiation and progression of cracks in masonry, in the range of 0.1 to 5 mm in width and thus corresponding to light damage [1], has allowed for the calibration of finite-element models that include a material model capable of accurately replicating this damage and which is populated with material properties corresponding to existing structures [6]. The models, which also include a soil-structure interaction boundary designed to account for the effect of the soil during earthquake vibrations [7], have been used to determine the fragility of masonry buildings via the proxy of 2D walls [2]. In the study presented herein, the finite element models are employed to replicate the geometry of (historical) masonry facades to determine their sensitivity to light damage as a consequence of the two damaging processes observed to be most common for this type of façade, namely (differential) settlements and (earthquake) vibrations [3]. The masonry façades were first pre-damaged via settlement distortions which generate just-visible cracks in the order of 0.1 mm to 1 mm in width. Then, an acceleration time history corresponding to two different Dutch earthquake events and two recordings of traffic-induced building vibrations [9] were separately applied at the base of the models. In this manner, the effect of existing damage could be assessed in regards to the aggravation generated by vibrations. The settlement part of the study revealed that long façades were more vulnerable to applied soil distortions, for instance. Then, subsequent vibrations further increased damage for intensities measured with a peak ground velocity (PGV) larger than 2 mm/s while the control set of virgin or uncracked façades remained undamaged at this PGV. At 32 mm/s, many pre-damaged façades also exceeded the light damage range. At equal PGV, the traffic vibrations, with a larger number of effective cycles, resulted in increased damage aggravation in comparison to the earthquake recordings.@en

Multi-source monitoring data and numerical analyses for the assessment of settlements affecting built-up areas in variable soil conditions

Conference paper - A. Prosperi, Gianfranco Nicodemo, M. Korff, M. Korff, Dario Peduto

This paper presents an integrated analysis based on the use of multi-source wide-area datasets consisting of hydro-mechanical properties of geomaterials, in-situ investigations/measurements (e.g. groundwater levels in wells) and innovative space-borne data (i.e. DInSAR techniques ...

2D and 3D Modelling Strategies to Reproduce the Response of Historical Masonry Buildings Subjected to Settlements

Journal article - A. Prosperi, M. Longo, Paul A. Korswagen, M. Korff, J.G. Rots

In this study, 2D and 3D modelling strategies are used to represent the behaviour of historical masonry buildings on strip foundations undergoing settlements. The application focuses on a two-story building, typical of the Dutch architectural heritage. An improved 2D modelling is ...

Contributed

1 records found

Influence of different subsidence-related drivers on damage to existing buildings

Master thesis - R.P. Meinen, M. Korff, R.B.J. Brinkgreve, Paul A. Korswagen, A. Prosperi

Subsidence is a significant geohazard affecting many areas globally, including the western part of the Netherlands. Subsidence is the lowering of the ground relative to the surface level, and it occurs both on the scale of a single structure and larger areas. The shallow subsurface in these areas, characterized by compressible soil, contributes to subsidence, which may be initiated or intensified by additional drivers. Subsidence can cause damage to buildings, leading to increased costs and social concerns In the current state of the art, less distinction is made regarding the difference in effects between different subsidence drivers. This study aims to provide insights into the relative influence of different drivers on the damage to existing buildings with a shallow foundation. More specifically, it aims to understand how various conditions and factors influence the damage parameters associated with soil deformation. This approach allows for analysing the interactions between the soil and the structure, ultimately contributing to a better understanding of the relative influence of the different drivers. Numerical models in PLAXIS 2D have been carried out to compute settlements for various scenarios, involving different soil scenarios, building scenarios, and subsidence drivers. The primary emphasis of numerical modelling lies on the soil rather than on the structure itself. Various damage parameters have been established based on the numerically calculated settlements. The purpose of this analysis is to determine the impact of settlements on the building based on these damage parameters. Several aspects related to settlement occurrence and its impact on buildings were investigated. The study provides multiple outcomes regarding the interaction between soil scenarios, different drivers of subsidence, and the presence of an existing building with and without a partial basement. This was achieved by considering the influence of each of these variables on the damage parameters, with emphasis placed on the relative influence of the different drivers. The approach includes a method that compares the influence of the situation with the existing building and the situation without the existing building (greenfield situation). This comparison shows the settlement behaviour caused by the presence of the building load and its interaction with the soil. Additionally, the combined effects of the soil scenarios, different drivers, and building scenarios on the resulting damage to an existing building are considered. To conclude, for the soil scenarios considered in this study, the soil scenario with a weak spot (SS3) has the most unfavourable effect on an existing building. For the drivers considered in this study, when evaluating the relative influence of the different drivers, the global groundwater lowering (D2glo) has the most unfavourable effect. Considering the combined effect, the soil scenario exerts the greatest influence on the resulting damage parameters for the evaluated scenarios, followed by the type of driver and the building scenario.