Mechanism of tunneling-induced cave-in of a busy road in Fukuoka city, Japan

A road cave-in accident caused by tunneling is described, and the possible mechanism of failure is analyzed. The cave-in measured about 30 m × 27 m in plane, and about 15 m in depth. At about 19 m below the ground surface at the site, a tunnel construction was underway. Immediately above the tunnel, there was a weathered shale layer approximately t 2.66 m thick; above this layer, there were sand and gravel layers. The groundwater level was estimated to be about 5 m below the ground surface. By arch analysis, it is shown that the most likely cause of the accident was the low strength of the weathered shale layer and the high water pressure above the tunnel, which resulted in tensile failure of the weathered shale layer. The All Ground Fasten (AGF) pre-support measure was adopted, but it might make very limited contribution to the increase in the tensile strength of the shale layer in the cross-sectional direction of the tunnel. Keywords: Tunneling, Road cave-in, Arch analysis, Tensile failur

Assessment of Geohazards and Preventative Countermeasures Using AHP Incorporated with GIS in Lanzhou, China

This research investigates geohazards and preventative countermeasures for Lanzhou City, China. To investigate the factors related to the development of geohazards in Lanzhou, the regional geological conditions around Lanzhou were investigated. The geomorphology of the region is comprised of a loess landform underlying quaternary loess deposits. A large number of faults induced by strong neotectonic movements are present in the area. Therefore, earthquakes frequently occur around Lanzhou. Earthquakes cause numerous rock falls and landslides, with landslide masses found scattered on the upper middle level of the area’s mountains. When intense rainfall occurs, a lot of loose deposits are brought together along steep gullies, forming debris flows; hence, a disaster chain of earthquake–landslide–debris flow is formed. To evaluate the georisks around Lanzhou, the Analytic Hierarchy Process (AHP) was employed to assess geohazards. The spatial distribution of the evaluated georisk levels was mapped using a Geographic Information System (GIS). Based on the assessed results, about 55% of the urban area and 44% of Gaolan County have high or very high-risk levels. The ratio of relatively high disaster risk levels is up to 31% of the total area. To mitigate these geohazards, both strategic decision making and technical countermeasures should be implemented

Investigation of Collapsed Building Incidents on Soft Marine Deposit: Both from Social and Technical Perspectives

A collapsed incident occurred on 10 October 2016 in Wenzhou City, China, which resulted in 22 casualties and 6 injuries. Most of victims were migrant laborers (rural dwellers who move to urban for a temporary work), who rented apartments in these residential buildings, which were originally constructed by local rural residents. This case report investigates the collapsed incident as well as other similar previous incidents. From the perspectives of both social and technical aspects, this report analyzed the Chinese rural land use policy with relevant technical factors. These incidents reveal social problems of the existing dual structure land-use policy in China. Chinese dual structure land-use policy caused deficiencies in the supervision of the construction market in rural area so that the following technical factors were not well supervised by the various quality control departments: (1) poorly quality of residential buildings, (2) unauthorized rooftop additions, and (3) differential settlement caused by the uneven distribution of underlying Wenzhou clay under creep conditions. Mandatory regulation by the government for any construction in China, particularly for the construction of self-constructed house building sites in rural areas, was recommended to minimize the resettlement issue of migrant workers

Assessment of Social-Economic Risk of Chinese Dual Land Use System Using Fuzzy AHP

The Chinese dual land use system (DLUS) has played a crucial role in the industrialization of China since 1950s. However, this dual system caused/causes obstacles in urban development under the new market economic conditions. This paper presents an approach to assess the social-economic risks during urban development in China by integrating the strategic environment assessment (SEA) principle into the fuzzy analytic hierarchy process (AHP) method. In the proposed approach, SEA principles are set as the influencing factors in AHP. Fuzzy AHP is used to assess the relative importance degree of the six principles in SEA. To illustrate the application procedure of the proposed approach, a building collapse incident in Wenzhou is used as a case for the risk analysis. The assessment results show that the index of the manage system has the greatest importance to social-economic risk. The principle of sustainable development (A) and monitoring measures (E) have more importance than the other principles in SEA. It can be concluded that the DLUS in the market management of China may be responsible for building collapse incidents in rural areas. It is suggested that the principles of sustainable development and monitoring measures in SEA should be strictly implemented during urbanization, and it is recommended that the government establish a unified management system and ensure the effective implementation of sustainable urbanization

Analysis and GIS Mapping of Flooding Hazards on 10 May 2016, Guangzhou, China

On 10 May 2016, Guangdong Province, China, suffered a heavy rainstorm. This rainstorm flooded the whole city of Guangzhou. More than 100,000 people were affected by the flooding, in which eight people lost their lives. Subway stations, cars, and buses were submerged. In order to analyse the influential factors of this flooding, topographical characteristics were mapped using Digital Elevation Model (DEM) by the Geographical Information System (GIS) and meteorological conditions were statistically summarised at both the whole city level and the district level. To analyse the relationship between flood risk and urbanization, GIS was also adopted to map the effect of the subway system using the Multiple Buffer operator over the flooding distribution area. Based on the analyses, one of the significant influential factors of flooding was identified as the urbanization degree, e.g., construction of a subway system, which forms along flood-prone areas. The total economic loss due to flooding in city centers with high urbanization has become very serious. Based on the analyses, the traditional standard of severity of flooding hazards (rainfall intensity grade) was modified. Rainfall intensity for severity flooding was decreased from 50 mm to 30 mm in urbanized city centers. In order to protect cities from flooding, a “Sponge City” planning approach is recommended to increase the temporary water storage capacity during heavy rainstorms. In addition, for future city management, the combined use of GIS and Building Information Modelling (BIM) is recommended to evaluate flooding hazards

Evaluation of Environmental Risk Due to Metro System Construction in Jinan, China

Jinan is a famous spring city in China. Construction of underground metro system may block groundwater seepage, inducing the depletion risk of springs. This paper presents an assessment of the risk due to metro line construction to groundwater in Jinan City using Analytic Hierarchy Process (AHP) and Geographic International System (GIS). Based on the characteristics of hydrogeology and engineering geology, the assessment model is established from the perspectives of surface index and underground index. The assessment results show that the high and very high risk levels of surface index exceed 98% in the north region; and high and very high risk levels of underground index exceed 56% in urban center and southern region. The assessment result also shows that about 14% of the urban area belongs to very high risk level; regions of high risk are 20% in urban area, 9% in Changqing County and 43% in Pingyin County. In the high risk region, metro lines R1 to R3, which are under construction, and metro lines L1 to L5, which are planned, have very high and high risk. Therefore, risk control measures are proposed to protect the groundwater seepage path to spring

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field