Potential Building Damage Research Articles

Assessing potential building damage caused by leakage to urban tunnels

AbstractBuilding damage is a major risk for urban tunnelling. In areas with soft soil conditions, water ingress to bedrock tunnels can cause significant pore pressure reduction, consolidation settlements and damage to nearby buildings and infrastructure. In Norway, guidelines to determine leakage limits are based on a national database, containing data on water ingress, pore pressure reduction and influence zone. To support future projects, the database has been implemented into an ArcGIS tool and merged with the Ground Impact and Building Vulnerability method to assess potential building damage at early project stages. In this paper, the adopted methodology is presented and its application is shown for a new subway tunnel in Oslo, Norway.

Early-stage assessment of structural damage caused by braced excavations: Uncertainty quantification and a probabilistic analysis approach

Current early stage assessment methods for deep excavation induced structural damage have large uncertainty due to modeling idealizations (simplification in analyses) and ignorance (incompleteness of information). This paper implements an elastoplastic two-stage solution of soil-structure-interaction to predict building response to adjacent deep excavations with braced supports. This soil-structure-interaction solution is then used to study the uncertainty in two case studies. A global sensitivity analysis is conducted, which indicates that the prediction of ground movement profiles is the major source of uncertainty in early stage building damage assessment. The uncertainty due to ignorance and idealizations related to structural analysis models also contribute significantly when target buildings are modeled as equivalent beams. However, the use of a 2-dimensional elastic frame structural model, in lieu of an equivalent beam, considerably reduces the assessment uncertainty. Considering the existence of uncertainty, a probabilistic analysis approach is proposed to quantify the uncertainty when predicting potential building damage due to excavation-induced subsidence. A computer program called Uncertainty Quantification in Excavation-Structure Interaction (UQESI) is developed to implement this probabilistic analysis approach.

3D Behaviour of Buildings due to Tunnel Induced Ground Movement

Ground subsidence from tunnel excavation below existing buildings may result in building distortion and develop structural damage. Previous case histories have shown that buildings may deform three-dimensionally when the tunnel alignment is orientated to the building facade. The authors incorporated a three-dimensional distortion parameter called twist into damage assessment by extending the current beam model to three dimensions. In this study, the new method is reviewed, and the concepts of the local and global twists are discussed. Results of a 3D Finite Element (FE) parametric study of global and local twist deformations of buildings due to tunnel-induced ground movement are compared in temporary and permanent cases during and after the construction of the tunnel. To investigate the behaviour of a twisted building, varying building stiffness, building geometry, and orientation angle are considered in the analyses. Comparison of the global and local twist shows that the global twist is not always the maximum twist during or after excavation of the tunnel. However, because of the temporary nature of the local twist, the global twist is still considered more critical than the local twist in terms of damage to the building. A new modification factor for the twist for different building stiffness factor is being proposed in the form of design graph. The design graph is included in the current three-stage procedure for assessing potential building damage. The modified procedure is used to predict the performance of a case study building affected by tunnel construction.

A simplified estimation of excavation-induced ground movements for adjacent building damage potential assessment

Adjacent building damages induced by excavations is crucial for excavations in urban areas. Excavation induced damage involved complex soil-structure interactions and complicated ground movements which should be evaluated at the depth of foundation of adjacent buildings. Empirical or semi-empirical methods for evaluation of ground movements induced by excavations have not been well-established because the observed ground movements are very limited. The objective of this study is to establish a simplified assessment for building damage potential based on subsurface ground movements caused by excavations. A series of parametric study by numerical analyses with an advanced soil model was carried out. A set of simplified equations for predicting the profiles for both subsurface ground settlements and lateral ground movements were proposed. Three assessment models with or without considering structural stiffness and subsurface ground movements were employed in estimating the damage potential index (DPI) for two case histories. The models were proved to yield a more reasonable assessment result for building DPI based on the proposed simplified expression of subsurface ground movements.

An Assessment of Earthquake Risk in Thecho of Kathmandu Valley Nepal: Scenario and Reality

Natural disaster cannot be stopped but its effect can be minimized or avoided by adopting technology and necessary human adjustment. Earthquake is a natural event which occurs without early warning signs. Computer based earthquake scenarios are used worldwide to describe and estimate the damage from potential earthquakes. The current study is an attempt to explore potential risk with respect to physical infrastructure and assess modeled and actual physical damage and human loss caused by different earthquake scenario and actual 2015 earthquake event in Thecho of Kathmandu valley. The earthquake scenario is based on two nearest fault lines. Risk Assessment Tools for the Diagnosis of Urban Seismic Risk (RADIUS) method has been applied for estimation of potential building damage and casualties..The research has adopted integrated approach using secondary and primary data sources such as field observation, key informant survey and building survey through purposive random sampling.The study found that potential building damage estimated by RADIUS for Gorkha 2015 earthquake scenario and North-west (Khokana) are lower than the actual post-earthquake assessment whereas North earthquake scenario resulted higher loss. Actual damage caused by 2015 earthquake compared to modeled damage from RADIUS is found higher because additional damaged were made by successive aftershocks. Spatial distribution of potential building damage for earthquake scenarios and actual 2015 earthquake event is also variable. North-Nuwakot Earthquake Scenario resulted more hazardous than the North-Khokana scenario though the location of epicenter is relatively farther with high intensity. The study concluded that though earthquake occurrence and disaster is still less predictable risk assessment tools like RADIUS and mitigation measures based on such is important for reducing risk of earthquake disaster.The Geographical Journal of NepalVol. 11: 127-136, 2018

Seismic Loss Estimation for Ward 14 of Mymensingh, Bangladesh

Mymensingh municipality is highly vulnerable to earthquake as it is located in close proximity of Madhupur Fault, Dauki Fault and Plate boundary Fault-2 as per a recent finding. As a result of rapid urbanization, economic expansion, population growth, urban-rural migration has made the locality more vulnerable to earthquake. This paper aims to assess the seismic vulnernability and potential economic loss at the event of earthquake for ward 14 of Mymensingh Municipality. For the assessment of seismic hazard, 12 borehole tests and 8 microtremor array measurements have been done. Based on the data of those tests, earthquake intensity map has been prepared using Geographic Information System (GIS) for the study area. For the estimation of economic loss caused by earthquake, potential building damage and human casualty have been estimated. For the assessment of potential building damage, a building inventory of the study area for 735 buildings has been done and potential building damage has been calculated by using fragility curves. Based on the occupancy rate of the study area, possible human injury and death rate have been estimated by using Morbidity Model proposed by Coburn. Combining the building vulnerability and human casualty, the potential economic loss at the event of earthquake for the study area has been estimated.

Earthquake Induced Deterministic Damage and Economic Loss Estimation for Kolkata, India

The city of Kolkata, the State Capital of West Bengal is jolted by earthquakes time and again from the tectonic regimes of the Central Himalaya, highly seismogenic Northeast India and the active tectonics of Bengal Basin which is a pericratonic tertiary basin on which the City is located. Earthquake disaster mitigation and management necessitates seismic hazard assessment for the generation of design response spectra at a site of interest with a zone factor for the computation of seismic coefficient to be adapted in building codes. The surface consistent probabilistic seismic hazard model of Kolkata for 475 years of return period have been used for the modeling of damage potential of buildings, human casualty and economic loss employing the widely used SEismic Loss EstimatioN applying a logic tree Approach (SELENA) in a relational analysis protocol considering eleven model building types. The demand spectrum curve of a spectral acceleration through a judicious interaction with the building capacity curve and fragility curve yields the damage state probability of the same in terms of slight, moderate, extensive and complete. Human casualty levels are also computed applying SELENA for three different times of the day viz. Night, Day and Commuting time. The economic loss to the tune of ~231 billion of Indian Rupees due to building damage only have been estimated within 300 socioeconomic clusters in the City. It is expected that this model will go a long way in safe urbanization process with well-defined disaster mitigation and management guidelines for the city of Kolkata.

Estimating building vulnerability to volcanic ash fall for insurance and other purposes

Volcanic ash falls are one of the most widespread and frequent volcanic hazards, and are produced by all explosive volcanic eruptions. Ash falls are arguably the most disruptive volcanic hazard because of their ability to affect large areas and to impact a wide range of assets, even at relatively small thicknesses. From an insurance perspective, the most valuable insured assets are buildings. Ash fall vulnerability curves or functions, which relate the magnitude of ash fall to likely damage, are the most developed for buildings, although there have been important recent advances for agriculture and infrastructure. In this paper, we focus on existing vulnerability functions developed for volcanic ash fall impact on buildings, and apply them to a hypothetical building portfolio impacted by a modern-day Tambora 1815 eruption scenario. We compare and contrast the different developed functions and discuss some of the issues surrounding estimation of potential building damage following a volcanic eruption. We found substantial variability in the different vulnerability estimates, which contribute to large uncertainties when estimating potential building damage and loss. Given the lack of detailed and published studies of building damage resulting from ash fall this is not surprising, although it also appears to be the case for other natural hazards for which there are far more empirical damage data. Notwithstanding the potential limitations of some empirical data in constraining vulnerability functions, efforts are required to improve our estimates of building damage under ash fall loading through the collection of damage data, experimental testing and perhaps theoretical failure analysis. For insurance purposes, the current building typologies provided for use with vulnerability functions are too detailed to map to the relatively limited information on building types that is typically available to insurers. Thus, efforts to provide vulnerability functions that can be used where only limited information is available regarding building types would also be valuable, both for insurers and for at-risk areas that have not been subject to detailed building vulnerability surveys.

Numerical study of long-term settlement following twin tunnel construction

finite element (FE) method to analyse the problem of long-term settlements following twin tunnel construction in low permeability clay. Similar ground conditions to those typically found in central London, UK, were modelled. The construction process of the tunnels was simulated and thereafter a special boundary condition was used, enabling the FE model to consider the tunnels as fully permeable drains during the post-construction period. Several tunnel depths and separations were studied. The long-term interaction between the tunnels and the manner in which the long-term displacements - both vertical and horizontal – developed, were analysed. Conclusions are drawn about the principal factors that drive these movements. Finally, the potential building damage associated with the short and long-term movements obtained from the FE analyses is assessed, compared and discussed. Keywords: twin tunnels, long-term settlement, clay, finite element, building damage

Testing the impact of at‐source stormwater management on urban flooding through a coupling of network and overland flow models

In many urban catchments, stormwater flooding is a serious problem. Low‐impact development and the use of stormwater control measures (SCMs) have the potential to mitigate such flooding, but this potential is highly context specific and remains largely untested. In this study, we tested the potential of SCMs to impact stormwater flooding in a peri‐urban catchment by coupling a one‐dimensional 1D stormwater drainage model with a two‐dimensional (2D) overland flow model. We predicted consequent flood dynamics for a range of storm events and management scenarios. We found that realistically extensive application of rain tanks and infiltration trenches is most effective in mitigating stormwater flooding for common‐to‐rare storm events [5‐ to 20‐year annual recurrence interval (ARI)] with short durations, such that the events have rainfall depths that are similar to the retention (or storage) capacity of commonly used small‐scale SCMs. Retention of stormwater also has the ability to mitigate overland flow intensity, positively impacting pedestrian safety and reducing potential building damage for rare events with ARIs above 20 years. In addition, SCMs also provide benefits to alternative options such as pipe upgrades, through their protection of receiving waters and enhancement of urban landscape amenity. WIREs Water 2015, 2:291–300. doi: 10.1002/wat2.1078This article is categorized under: Engineering Water > Sustainable Engineering of Water Science of Water > Water Extremes

PROBABILITY-BASED SERVICEABILITY EVALUATION OF BUILDINGS ADJACENT TO AN EXCAVATION USING RANDOM FINITE ELEMENT METHOD

Excavation design is usually controlled by the serviceability-based analysis of buildings adjacent to the excavation site. In practice, it is not easy to implement the serviceability-based analysis due to the uncertainty of many factors affecting excavation behavior. It is desirable to incorporate the probability analysis into the procedure to deal with the effects of the uncertainty in an excavation problem. In this present study, the Monte Carlo simulation is equipped into the existing finite element method code, which is capable of representing the small-strain stress–strain characteristics of soils, to form the random finite element method (RFEM). Then, the RFEM is employed to perform the probability-based serviceability evaluation of buildings adjacent to an excavation on a quality excavation case history. A flow chart for RFEM-based evaluation of excavation-induced damage to buildings is established. In addition, a simplified method, called the KJHH method, is also adopted to conduct the probability-based analysis on the issue of building damage potential. Three scenarios were planned to compare the performance of the RFEM and the KJHH methods. The results reveal that the developed RFEM is validated to be a useful tool to consider the uncertainty of input parameters in the evaluation of the damage potential of buildings adjacent to excavation.

Spatial Data Clustering and Zonation of Earthquake Building Damage Hazard Area

Research conducted with the aim to develop spatial data cluster and analyse the characteristics of each cluster of data in order to develop spatial zonation of building damage hazard caused by the earthquake in the city of Banda Aceh. The data used consists of the data peak ground acceleration (PGA), lithology and topographic zone data with the four phases of the study consisted of data normalization with min-max method, determination of optimum data group with the connectivity index, Dunn index and the Silhouette index, clustering of data with the k-Means algorithm and the data interpolation using kriging algorithm to construct the zonation of hazard area. The optimum numbers of clusters used in these researches are two, with the first 170 data largely concentrated at a distance of less than 0.1 to 0.5 from the cluster centre and the second 55 others data concentrated at a distance of 0.3 - 0.5 from the cluster centre. Banda Aceh and surrounding areas can be spatially divided into two classes of potential building damage caused by the earthquake with high hazard class building damage are generally located near the coastline.

Probabilistic Inverse Analysis of Excavation-Induced Wall and Ground Responses for Assessing Damage Potential of Adjacent Buildings

This paper presents an approach for the probabilistic inverse analysis of braced excavations based on the maximum likelihood formulation. Here, the soil parameters are updated using the observations of the maximum ground settlement and/or the maximum wall deflection measured in a staged excavation. The updated soil parameters are then used to refine the predicted wall and ground responses in the subsequent excavation stages, as well as to assess the building damage potential at the final excavation stage. Case study shows that the proposed approach is effective in improving the predictions of the excavation-induced wall and ground responses. More-accurate predictions of the wall and ground responses, in turn, lead to a more accurate assessment of the damage potential of buildings adjacent to the excavation. The proposed approach offers an effective means for a probabilistic inverse analysis of braced excavations.

Fully Probabilistic Framework for Evaluating Excavation-Induced Damage Potential of Adjacent Buildings

This paper presents a framework for a fully probabilistic analysis of the potential for damage to buildings adjacent to an excavation. Herein, the damage potential index (DPI), which is a function of angular distortion and lateral strain, is used to assess building damage potential. A serviceability limit state is established in which the resistance is expressed in terms of the “limiting” DPI, and the load is represented by the “applied” DPI. In this context, damage to the building adjacent to an excavation is said to occur deterministically if the applied DPI is greater than the limiting DPI. For the fully probabilistic analysis, both parameter and model uncertainties of the limiting and applied DPIs are first characterized. The analysis framework is then presented and demonstrated with a case history. Finally, sensitivity analysis is performed to identify the factors to which the probability of damage is most sensitive and to analyze the effect of various assumptions of the input parameters on the compu...

Numerical study of damage potential in buildings due to excavations

Evaluation industrial factory building damage potential due to ground movements caused by excavations inside the building is a critical design consideration when reconstructing the underground equipment of the industrial factory building. In this paper, the behavior of a support system for a reconstruction project of underground equipment of the industrial factory building in Shanghai and its effects on a pile-foundation supported building are presented. The 8.1 m deep excavation is made through soft clay to fine sand and retained by the 800 mm thick pile wall and the bracing system. Field observation data are collected, especially such as the lateral displacements of columns, settlement of cushion caps, and general building deformation trends. A 3D finite element method (FEM) procedure is demonstrated here with considering of interaction between soils and structures, and is conducted to examine responses of retaining wall, columns, and cushion caps due to excavations. The proposed numerical model is shown to adequately reflect the responses of the industrial building factory caused by excavations inside the building. The results of numerical prediction are close to the field observation.

Simplified Model for Evaluating Damage Potential of Buildings Adjacent to a Braced Excavation

This paper presents a simplified model for evaluating damage potential of a building adjacent to a braced excavation. New developments include several component models for estimating the lateral ground movement profile, angular distortion and lateral strain in a building, and damage potential of a building adjacent to an excavation. These new developments along with an existing model for the vertical ground movement profile are integrated into the proposed simplified model. Case histories are used to verify the developed simplified model. Furthermore, the uncertainty in the developed model is quantified, which enables a probabilistic assessment of the excavation-induced building damage potential. An example probabilistic assessment of building damage potential is presented.

Seismic hazard and risk in Shanghai and estimation of expected building damage

The People's Republic of China is in the process of rapid demographic, economic and urban change including nationwide engineering and building construction at an unprecedented scale. The mega-city of Shanghai is at the centre of China's modernisation. Rapid urbanisation and building growth have increased the exposure of people and property to natural disasters. The seismic hazard of Shanghai and its vicinity is presented from a seismogenic free-zone methodology. A PGA value of 49 cm s −2 and a maximum intensity value of VII for the Chinese Seismic Intensity Scale (a scale similar to the Modified Mercalli) for a 99% probability of non-exceedance in 50 years are determined for Shanghai city. The potential building damage for three independent districts of the city centre named Putuo, Nanjing Road and Pudong are calculated using damage vulnerability matrices. It is found that old civil houses of brick and timber are the most vulnerable buildings with potentially a mean probability value of 7.4% of this building structure type exhibiting the highest damage grade at intensity VII.

Evaluation of Building Stiffness for Building Response Analysis to Excavation-Induced Ground Movements

A major element in the design and construction of tunnels and braced excavations in urban areas is the control of ground movements and protection of adjacent or overlying structures, which are often constructed with masonry and set on shallow foundations. Initial evaluation of potential building damage is obtained by assuming that building distortion is compliant with the imposed ground movements. Further investigations take into consideration the reduction in building distortion that occurs as a result of building stiffness. Presented in this paper are the results of numerical analyses for evaluating the equivalent bending and shear stiffness of masonry structures taking into account the anisotropy of the masonry units and the percentage of window openings. The distinct element code, UDEC, has been used to model each masonry block and the mortar between blocks for masonry walls in plane stress conditions. Parametric studies, conducted for a range of window opening percentage and brick/mortar joint stiffn...

A tool for tunneling-induced building damage risk assessment

Simple software for the evaluation of building damage potential due to new tunnel construction is developed in this study. The developed software consists of two main modules: ground settlement analysis module and building damage assessment module. The tunneling-induced ground movement is evaluated by using the analytical solutions and the empirical methods. The building damage potential is evaluated by simple criteria using the predicted ground movement. The advantages of the software are its user-friendliness, requirement of easily available input data, and faster evaluation time. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.

Geotechnical investigation and assessment of potential building damage arising from ground movements: CrossRail

One of the largest geotechnical survey and site investigations ever carried out in London, costing approximately £3 million, was undertaken prior to the design of the underground sections of CrossRail. This paper outlines the procurement, management and technical aspects of this survey, the application of the results to the prediction of ground movements arising from tunnelling and the design of building protective works.