Ancillary Building Research Articles

Inundation Extent Mapping by Synthetic Aperture Radar: A Review

Recent flood events have demonstrated a demand for satellite-based inundation mapping in near real-time (NRT). Simulating and forecasting flood extent is essential for risk mitigation. While numerical models are designed to provide such information, they usually lack reference at fine spatiotemporal resolution. Remote sensing techniques are expected to fill this void. Unlike optical sensors, synthetic aperture radar (SAR) provides valid measurements through cloud cover with high resolution and increasing sampling frequency from multiple missions. This study reviews theories and algorithms of flood inundation mapping using SAR data, together with a discussion of their strengths and limitations, focusing on the level of automation, robustness, and accuracy. We find that the automation and robustness of non-obstructed inundation mapping have been achieved in this era of big earth observation (EO) data with acceptable accuracy. They are not yet satisfactory, however, for the detection of beneath-vegetation flood mapping using L-band or multi-polarized (dual or fully) SAR data or for urban flood detection using fine-resolution SAR and ancillary building and topographic data.

PERFORMANCE OF REINFORCED CONCRETE HOSPITAL BUILDING SUBJECTED TO EARTHQUAKE USING BASE-ISOLATION SYSTEM

The frequent occurrence of earthquake in the Bangladesh and up-gradation of seismic design code (BNBC-1993) has heightened the need for investigation of seismic performance of existing lifeline structure specially hospital building. The objective of this study is to evaluate seismic capacity and corresponding improvement of an existing hospital building (Ancillary Building) of Chittagong Medical College Hospital (CMCH). For this purpose, a three dimension (3-D) numerical model of Ancillary Building (AB) of CMCH was developed using SAP 2000 finite element program. A non-linear static analysis was performed to determine seismic capacity of the building model. The result indicates the seismic capacity of the hospital building is sufficient to mitigate the seismic demand according to BNBC-1993, whereas the seismic capacity is found insufficient as per revised BNBC. To reduce the seismic effect on AB, base-isolation devices have been designed and were used as link element to the numerical model. The application of base-isolation devices as a retrofitting strategy makes the considered hospital building safer for seismic excitation suggested in revised BNBC.

SEISMIC FRAGILITY ASSESSMENT AND RETROFIT OF A GOVERNMENT HOSPITAL BUILDING IN CHITTAGONG, BANGLADESH

Chittagong Medical College Hospital (CMCH) is one of the most important government hospitals in Bangladesh. It is located in the heart of Chittagong city, the only port city of Bangladesh. Bangladesh National Building Code (BNBC) is the only official document, which has been used since 1993 as guidelines for seismic design of buildings. As per the guidelines of BNBC, the CMCH building was designed for an earthquake ground motion having a return period of 200 years. However, the revised version of BNBC has suggested that the building structures shall be designed for an earthquake ground motion having a return period of 2475 years. It is mentioned that a single seismic performance objective, the life safety, of the building is considered in both versions of BNBC. Considering the significant importance of CMCH building in providing the emergency facilities during and after the earthquake, it is indispensable to evaluate its seismic vulnerability for the two types of earthquake ground motion records having return period of 200 (Type-I) and 2475 (Type-II) years. In this regard, this paper deals with the seismic vulnerability assessment of the existing ancillary building (AB) of CMCH. The seismic vulnerability of building is usually expressed in the form of fragility curves, which display the conditional probability that the structural demand (structural response) caused by various levels of ground shaking exceeds the structural capacity defined by a damage state. The analytical method based on elastic response spectrum analyses results is used in evaluating the seismic fragility curves of the building. To the end, 3-D finite element model of the building subjected to 18 ground motion records having PGA of 0.325g to 0.785g has been used in theresponse spectrum analysis in order to evaluate its inter-story-drift ratio (IDR), an engineeringdemand parameter (EDP) for developing fragility curves. The analytical results have shown thatstructural deficiencies exist in the existing ancillary building (AB) for the Type-II earthquakeground motion record, which requires the building to be retrofitted to ensure that the existingancillary building (AB) becomes functional during and after the Type-II earthquake groundmotion record.

SEISMIC FRAGILITY ASSESSMENT AND RETROFIT OF A GOVERNMENT HOSPITAL BUILDING IN CHITTAGONG, BANGLADESH

Chittagong Medical College Hospital (CMCH) is one of the most important government hospitals in Bangladesh. It is located in the heart of Chittagong city, the only port city of Bangladesh. Bangladesh National Building Code (BNBC) is the only official document, which has been used since 1993 as guidelines for seismic design of buildings. As per the guidelines of BNBC, the CMCH building was designed for an earthquake ground motion having a return period of 200 years. However, the revised version of BNBC has suggested that the building structures shall be designed for an earthquake ground motion having a return period of 2475 years. It is mentioned that a single seismic performance objective, the life safety, of the building is considered in both versions of BNBC. Considering the significant importance of CMCH building in providing the emergency facilities during and after the earthquake, it is indispensable to evaluate its seismic vulnerability for the two types of earthquake ground motion records having return period of 200 (Type-I) and 2475 (Type-II) years. In this regard, this paper deals with the seismic vulnerability assessment of the existing ancillary building (AB) of CMCH. The seismic vulnerability of building is usually expressed in the form of fragility curves, which display the conditional probability that the structural demand (structural response) caused by various levels of ground shaking exceeds the structural capacity defined by a damage state. The analytical method based on elastic response spectrum analyses results is used in evaluating the seismic fragility curves of the building. To the end, 3-D finite element model of the building subjected to 18 ground motion records having PGA of 0.325g to 0.785g has been used in theresponse spectrum analysis in order to evaluate its inter-story-drift ratio (IDR), an engineeringdemand parameter (EDP) for developing fragility curves. The analytical results have shown thatstructural deficiencies exist in the existing ancillary building (AB) for the Type-II earthquakeground motion record, which requires the building to be retrofitted to ensure that the existingancillary building (AB) becomes functional during and after the Type-II earthquake groundmotion record.

PENGAMBILAN KEPUTUSAN "MENGERJAKAN SENDIRI" ATAU "SUBKONTRAK" PADA PELAKSANAAN PROYEK DENGAN PENERAPAN MODEL MULTIKRITERIA

The Project Management and Service Department of PT Boma Bisma Indra (BBI-MPJ) encounters numerous civil works in building a Crude Palm Oil (CPO) Refinery Plant. A decision involving many factor has to be made between in-house construction or subcontracting. A multiple criteria decision model involving Analytical Hierarchy Process (AHP) in conjunction with Utility Function was employed in this study to solve the problem of choosing the best alternative. This model was used to optimisefour objectives, i.e. maximizing Strategic Competitive Performance, Managerial Performance, Financial Performance and minimizing Risk. The results obtained indicated that all the civil works should be subcontracted. Civil works for Machinery Foundation was contracted to Subcontractor SA2, and Ancillary Building to Subcontractor SB2; while mechanical works Steel Structure and Platform (Threshing and Pressing Station), Steel.Structure and Platform Lot 7 and Steel Structure and Platform Lot 5 were contracted to Subcontractors M42, MBI, and MC2 respectively.

Building Damage Assessment Using High-Resolution Satellite SAR Images of the 2010 Haiti Earthquake

Damage to individual buildings in an urban area of Port-au-Prince, Haiti, from the 2010 Haiti earthquake was assessed by means of high-resolution synthetic aperture radar (SAR) intensity images and ancillary building footprints. A comparison of pre- and post-event images and a building damage inventory showed that backscattering intensity between images was more significantly changed in collapsed buildings than in less damaged buildings. The linear discriminant function, based on the difference and correlation coefficient of the images was developed to detect collapsed buildings. The result showed that almost 75% of the buildings were correctly detected by discriminant analysis. An accuracy assessment revealed the difficulty of detecting small and congested buildings because the number of image pixels was too small and the buildings were obscured by neighboring buildings and other features in the images.

A Soft Computing Method for Damage Mapping Using VHR Optical Satellite Imagery

In this research, the feasibility of a method based on some soft computing algorithms for earthquake damage mapping is sought. The idea is to classify different patterns of change associated with building footprints and to detect distinct damage levels. A fuzzy inference methodology is employed to determine the damage grade for individual building roofs by the means of evaluating the contribution of different patterns of changes. For implementation, satellite images of before and after the 2003 Bam, Iran earthquake, are used in addition to some available ancillary data. Building footprint pixels were extracted from pre- and postimages using the ancillary building mask. Haralick second-order textural features were computed for the building objects and an optimum set of such features was selected using genetic algorithm (GA). Considering optimal indices, different parts of roofs were classified into three change patterns as “low change,” “moderate change,” and “severe change” employing a support vector machine (SVM) algorithm. For each building footprint, the contribution of each class was calculated as the input of a fuzzy inference system (FIS). Mamdani fuzzy engine was used to determine the damage grade of each building. The proposed algorithm was evaluated by comparing the produced damage map with a reference damage map (ground truth). The results demonstrated the efficacy of the method showing overall accuracies of 76% for detecting three levels of structural damage (no to slight, moderate, and heavy to destruction) and 89% for determining binary damage levels (no-collapsed, and collapsed) as suitable for such overall monitoring process.

Dechenphug : destin d'un monastère bhoutanais

Conservation works on Dechenphug, a small monastery in Bhutan, were carried out from 1996 to 1999 under the scientific control of Unesco. From the beginning, a strong disagreement was obvious between the ethics of the international organisation and the current local practice. A compromise was eventually agreed, a proof that both approaches are not always irreconcilable. Field training of local actors was a an important component of the project, which included the reconstruction of an ancillary building, the restoration of woodwork and roofs on the other two buildings, and the conservation of a mural painting.

Medieval Iron-Workings in Minepit Wood, Rotherfield, Sussex

FROM 1965 TO 1967 detailed excavations were carried out in Minepit Wood, Rotherfield, Sussex, on what proved to be a complete and undisturbed iron-working site of the 14th and 15th centuries. Two periods were distinguished. Except for part of the roasting-furnace nothing survived of the earlier structures. The remains of the later period (which followed closely on the earlier) included a dump of natural ore prepared for roasting; a stone-built roasting-furnace with attendant heap of ore-roasting refuse; a stone and clay smelting-furnace and slag-heap; the groundwalls of a timber-framed building, which had been partly roofed and enclosed the smelting-furnace and supplies of roasted ore and charcoal; the ground- walls of a small ancillary building; and a few pieces of iron and contemporary pottery. One of the many minepits, which gave the wood its name, was also shown to be late medieval.