Sanding Wells on The Island of Lombok due to Earthquake Vibrations

The Lombok earthquake in 2018 was unique, the shocks occurred sequentially. Several major earthquakes were followed by thousands of aftershocks. The earthquake caused a devastating disaster which destroyed many homes, buildings including wells as the main fresh water supply in the Lombok Island. The focal mechanism of main earthquake shows a thrust fault mechanism. Lombok Island is originally a volcano Island which is still growing actively. Therefore surface of Island is dominated by volcanic materials, such as: volcanic rock, volcanic ash, pumice. This paper describes the phenomenon of sanding wells in Lombok, including the physical mechanisms among rock’s grains when vibrating earthquake waves. These earthquake waves can eliminate static friction between grains and reduce cohesion between grains of rock. Some subsurface images shows a strong correlation between damage grade and the existence of loose sand and hard rock.

Statistical analysis and modeling to examine the exterior and interior building damage pertaining to the 2016 Kumamoto earthquake

After an earthquake occurs, field surveys are conducted by relevant authorities to assess the damage suffered by buildings. The field survey is essential as it ensures the safety of residents and provides the necessary information to local authorities for post-disaster recovery. In Japan, a primary (mandatory) exterior survey is conducted first, and a secondary (voluntary) interior survey is performed subsequently if the residents request a reinvestigation. However, a major challenge associated with field surveys is the substantial time cost of determining the damage grades. Moreover, an interior survey is performed only after receiving the reinvestigation request from occupants, which further delays the decision-making process. In addition, the risk of incorrect damage estimation during the exterior survey must be considered because underestimating the damage can endanger the residents. Therefore, in this study, a three-part analysis (Parts I–III), where each part corresponds to a distinct stage of the standard damage assessment procedure, was performed to characterize the relationship between the building parameters and damage grades at different stages. To further explore the possibility of accelerating decision-making, predictive modeling was performed in each part. The Part I results indicate that estimating the final damage grade for all buildings immediately after the exterior survey is similar to treating the exterior survey results as the final ones. The Part II results show that buildings that potentially require an interior survey can be predicted with reasonable accuracy after the exterior survey. In buildings for which reinvestigations have been requested, Part III demonstrates that the risk of underestimation in the exterior survey can be predicted reliably.

Rapid Estimation of Spatial Distributions of Building Damages in the 30 October 2020 Aegean Sea Earthquake

<p>An Mw 6.9 (Ml 6.6) earthquake occurred at an estimated focal depth of 12 km in the Aegean Sea on October 30th, 2020. 115 people died in Turkey in the devastating earthquake, it left more than one thousand people injured and several hundreds of families in need of a shelter. The strong ground shaking further amplified by local site effects caused building collapses and substantial damages throughout the city of Izmir (Turkey) as well as in Samos Island (Greece). In the aftermath of the event, an intensity-based damage analysis was conducted for the rapid estimation of number of damaged buildings at regional scale. For this purpose, first, spatial distributions of PGA, PGV values and instrumental intensities were computed by also incorporating the recorded ground motion data made available by several institutions. Numbers of damaged buildings at each EMS-98 damage grade were then estimated using the intensity-based, regionally adjusted structural vulnerability relationships. This paper presents the geographical distributions of rapid damage estimations and compares them to the observational damage data.</p>

An interdisciplinary approach to landslide damage assessment in urban areas

<p>This paper presents some results of a multidisciplinary research about the assessment of damages to ordinary buildings at the urban scale in landslide areas. The methodology represents part of a multi-level approach for landslide vulnerability assessment that has been recently developed. It is based on rapid visual inspections of the buildings, the application of ‘simple models’ to interpret the structural response, the geological and geotechnical knowledge of the site. The end-product is the landslide damage geotechnical chart, including: i) the damage grade of the buildings, ii) the geomorphological and geotechnical map of the area, iii) the direction of the settlements causing damages. The application of the methodology to an historical site in southern Italy is also outlined. Finally, the contribution of innovative non-invasive spaceborne remote sensing techniques to monitor landslide-affected urban areas is highlighted.</p>

Effect of endodontic treatment on periodontal healing of grade 3 endo-periodontal lesions without root damage in periodontally compromised patients—a retrospective pilot study

Objectives There is little evidence about the effect of different treatment protocols for grade 3 endo-periodontal lesions without root damage in patients with periodontitis according to the new classification of periodontal disease. The aim of this study is to evaluate the impact of endodontic treatment on the achievement of periodontal healing. Materials and methods Teeth with the initial diagnosis endo-periodontal lesion without root damage grade 3, treated with a standardized endodontic treatment protocol, were included in this study. A retrospective analysis was performed to assess the impact on periodontal healing by evaluating probing pocket depth (PPD), clinical attachment gain (CAL), and periapical index score (PAI). Results Nineteen teeth and 13 patients were included. A mean reduction of 3.19 ± 3.41 mm in PPD was recorded. The mean CAL gain was 2.33± 3.75 mm. Five teeth (45.4%) showed an improvement of PAI and were classified as treatment success. Conclusions The results failed to show a highly predictable treatment outcome for endo-periodontal lesion grade 3 without root damage in patients with periodontitis. However, endodontic therapy alone resulted in treatment success for some of the teeth, which would otherwise have had a poor prognosis. Clinical relevance Endo-periodontal lesions can often be challenging for dentists in daily clinical practice. To date, there is not much evidence for practitioners to rely on. Therefore, this study aims to strengthen the evidence for the management and treatment of endo-periodontal lesions. Although the outcome is not highly predictable yet, teeth with the initial diagnosis endo-periodontal lesion without root damage grade 3 can benefit from an endodontic treatment.

Liver damage in patients living with HIV on antiretroviral treatment with normal baseline liver function and without HBV/HCV infection: an 11-year retrospective cohort study in Guangxi, China

ObjectiveTo characterise the association between duration of exposure to antiretroviral treatment (ART) and liver damage in HIV patients with an initially normal baseline liver function and without hepatitis B virus (HBV)/hepatitis C virus (HCV) infection.MethodsA retrospective cohort study was conducted in HIV-infected individuals with normal liver function parameters at ART initiation and without HBV/HCV infection, from 14 April 2004 to 13 April 2015 in Guigang city, Guangxi, China. The association between duration of ART and liver damage (grade II–IV liver enzyme elevation [LEE] and/or total bilirubin elevation [TBE]), was analysed. Cox regression was used to examine the factors related to liver damage.ResultsOf 2119 eligible patients, 12.41% (263/2119) developed liver damage (grade II–IV LEE/TBE) and contributed 4.11/100 person-years crude incidence rate. The highest liver damage incidence was observed in patients with 6–12 months’ ART (15.16/100 person-years). The incidence decreased to 5.56/100 person-years in patients with 12–18 months’ ART and 3.13/100 person years in patients with 18–24 months’ ART, and then maintained at a relatively low and stable level in patients with 2 years’ ART or longer (average of 3.65/100 person-years). Cox regression analysis revealed that current WHO disease stage II, III or IV (compared with stage I) were the risk factors for liver damage, while baseline disease stage II, III (compared with stage I) and current regimen 3TC+AZT+NVP were the protective factors for liver damage.ConclusionsLiver damage always exists among HIV-infected patients on ART with normal baseline liver function and without HBV/HCV infection. Nevertheless, cumulative ART duration does not increase the risk of liver damage. ART could tend to be long-term, however, monitoring and management of liver damage among patients on ART are also important in clinical therapy.