油气长输管道滑坡地质灾害危险性评价专家系统研究

以运营的油气长输管道工程为依托,在收集、整理、综合分析既有资料基础上,通过对大量滑坡案例进行分析,明确了滑坡地质灾害的主要诱发因素与稳定性控制指标,建立了滑坡危险性评价指标体系。应用专家系统研究方法,建立油气长输管道线路滑坡地质灾害危险性评价专家系统,并对具体工程进行了地质灾害危险性评估,结果符合实际,可为油气长输管道工程地质灾害减灾防灾提供技术支撑。     

泰青威天然气管道临朐段水毁灾害分布特征与风险评价

对泰青威天然气管道临朐段地质灾害发育特征进行调查研究发现,临朐段地质灾害类型主要为水毁灾害,具体可分为坡面水毁、河沟道水毁和台田地水毁。野外地质灾害实地调查临朐段管道沿线共发现地质灾害15处,其中坡面水毁点6处,河沟道水毁点4处,台田地水毁点5处。采用定性与半定量相结合的评价方法对其进行地质灾害风险评价,结果表明: 地质灾害风险等级较高的有1处,占6.66%; 风险等级中等的有4处,占26.67%; 风险等级较低的有10处,占66.67%。根据管道沿线地形地貌、地质灾害发育密度、风险等级等因素,划分地质灾害中易发区61 km,低易发区10 km,管道沿线以地质灾害中易发区为主。最后,针对不同类型、不同风险等级地质灾害提出了相应的防治消减措施,为后期管道安全运营和风险整治决策提供了有效的技术依据。     

Seismic risk assessment and hazard mapping in Nepal

Natural Hazards - Seismic risk in the form of impending disaster has been seen from past records that moderate-to-large earthquakes have caused the loss of life and property in all parts of Nepal....     

Seismic risk assessment of buildings in Izmir,Turkey

Izmir, the third largest city and a major economic center in Turkey, has more than three million residents and half million buildings. In this study, the seismic risk in reinforced concrete buildings that dominate the building inventory in Izmir is investigated through multiple approaches. Five typical reinforced concrete buildings were designed, modeled and assessed for seismic vulnerability. The sample structures represent typical existing reinforced concrete hospital, school, public, and residential buildings in Izmir. The seismic assessments of the considered structures indicate that they are vulnerable to damage during expected future earthquakes.     

Active faults pattern and interplay in the Azerbaijan region (NW Iran)

Northwest Iran is dominated by two main sets of active strike slip faults that accommodate oblique convergence between the Arabian and Iranian Plates. The best known are the right-lateral North-Tabriz, Qoshadagh, Maragheh and Zagros (Main Recent) strike slip Faults. This work reports that these dominant NW–SE to E–W striking faults are conjugate to smaller, NNE–SSW striking, left-lateral faults with minor dip slip component. All of these active faults displace Precambrian rock units, which suggests that they root in the crystalline basement of the NW Iranian microcontinent. Coulomb stress variance during co-seismic rupture along one of these faults may cause reactivation of the other faults. The minor set of left-lateral fault is therefore important to introduce in seismic risk assessment.     

Seismic risk assessment and mapping at different levels

In 2012, the damage costs of floods in Russia amounted to about €300m, and these floods have caused nearly 200 fatalities (Kotlyakov et al. in Reg Res Rus 3(1):32–39, 2013). Risk assessment is one of the most pressing scientific topics in Russia, but most of the works are devoted to natural hazards assessment. The purpose of this work is to estimate the influence of hazardous hydrological phenomena on society. The field research was conducted in the Slavyansk municipal district in the Krasnodar region (the south-western part of Russia), which is a highly populated coastal territory with a high frequency of hazardous hydrological events. Modified methods of the Ministry of the Russian Federation for Affairs for Civil Defence, Emergencies and Elimination of Consequences of Natural Disasters (EMERCOM) were used for potential economic damage calculation. The paper did not only focus on direct, tangible risks, but also included social risk (i.e. risk to life and health). Social vulnerability has been calculated directly as a percentage of vulnerable people, estimated in opinion polls, while in many recent papers the social vulnerability index was calculated as a combination of several statistical indicators. The resulting percentage of vulnerable people was converted to numbers of potential victims. Finally, the social risk was expressed by financial indicators in terms of the cost of the value of statistical life lost (Mrozek and Taylor in J Policy Anal Manag 21(2):253–270, 2002; Viscusi and Aldy in J Risk Uncertain 27(1):5–76, 2003). Social risk can be underestimated in comparison with economic risk because of a low “value of life” in Russia (no life insurance, neglecting of basic safety rules, etc.) (Guriev in Myths of economics, Alpina Business Books, Moscow, 2009).     

On the occurrence of analcime in the northeastern Azerbaijan volcanics (northwestern Iran)

Euhedral, phenocryst-like crystals of analcime, as well as microlites, are rather common in phonolitic and tephritic lavas and in some anaicitic dikes and lenses of the Upper Cretaceous and Lower Tertiary volcanics of eastern Azerbaijan (Iran). The mineralogy and petrology of these extrusive rocks are described with the aim of establishing the origin of the big analcime crystals. While the mineralogical data (e.g. true symmetry, Al/Si disorder and Na atom distribution, structural refinements) are not conclusive, the paragenesis and microprobe analyses of analcime and associated phases, mainly feldspars, lead us to believe they are of a secondary, metasomatic origin. It is suggested that during late or post-magmatic stages analcime may have originated either from ion-exchanged leucite or by alteration or interaction between pre-existing Na-rich phases such as nepheline, feldspars and glass at subsolidus temperatures.     

Seismic risk assessment and mapping at different levels

Earthquakes incur the greatest damage compared with all the other natural deleterious occurrences; when occurring in industrialized and densely populated regions, they can prove devastating. In the Russian Federation, we have more than 20 million people living in regions of moderate and high seismicity. The areas that are hit by earthquakes, with events of intensity VII (MMSK-86 scale) or greater occurring, make up approximately 20% of Russia’s area. The present paper addresses the methodological procedures of risk assessment and databases used for risk computations at different levels. The examples of seismic risk assessment and mapping at different levels: country, region and urban, are given. Special attention is paid to information and web technologies used for verification data on built environment inventory and vulnerability.     

Seismic hazard assessment of the city of Hamedan and its vicinity, west of Iran

This article presents the results of deterministic and probabilistic seismic hazard analyses (DSHA and PSHA) of the city of Hamedan and its neighboring regions. This historical city is one of the developing cities located in the west of Iran. For this reason, the DSHA and PSHA approaches have been used for the assessment of seismic hazards and earthquake risk evaluation. To this purpose, analyses have been carried out considering the historic and instrumented earthquakes, geologic and seismotectonic parameters of the region covering a radius of 100?km, keeping Hamedan as the center. Therefore, in this research, we studied the main faults and fault zones in the study area and calculated the length and distance of faults from the center of Hamedan. In the next step, we measured the maximum credible earthquake (MCE) and peak ground acceleration (PGA) using both DSHA and PSHA approaches and utilized the various equations introduced by different researchers for this purpose. The results of DSHA approach show that the MCE-evaluated value is 7.2 Richter, which might be created by Nahavand fault activities in this region. The PGA value of 0.56?g will be obtained from Keshin fault. The results of PSHA approach show that the MCE-evaluated value is 7.6 Richter for a 0.64 probability in a 50-year period. The PGA value of 0.45?g will be obtained from Keshin fault. Seismic hazard parameters have been evaluated considering the available earthquake data using Gutenberg?CRichter relationship method. The ??a?? and ??b?? parameters were estimated 5.53 and 0.68, respectively.     

Analysis of the stress regime and tectonic evolution of the Azerbaijan Plateau,Northwestern Iran

The increasing number of earthquakes in recent decades in Northwestern Iran and the determination of the epicenters of these events makes possible to estimate accurately the changing tectonic regime using the Win-Tensor inversion focal mechanism program. For this purpose focal mechanism data were collected from various sources, including the Centroid Moment Tensor catalog (CMT). The focal mechanism and fault slip data were analyzed to determine change in the stress field up to the present day. The results showed that two stages of brittle deformation occurred in the region. The first stage was related to Eocene compression in NE–SW direction, which created compressional structures with NW–SE strike, including the North and South Bozgush, south Ahar and Gushedagh thrust belts. The second brittle stage began in the Miocene with NW–SE compression and caused developing thrusts with N–S trends that were active presently. These stress regimes were created by the counter-clockwise rotation of the Azerbaijan plateau caused by movement on strike slip faults and continuous compression between the Arabian plate, the south Caspian basin and the Caucasus region. Pliocene-Quaternary activity of the Sabalan and Sahand volcanoes as well as recent earthquakes occurred as a result of this displacement and rotational movement. The abundance of hot springs in the Ardebil, Hero Abad and Bostanabad areas also bore witness to this activity.     

Contamination and ecological risk assessment of heavy metals in street dust of Tehran,Iran

Heavy metals are introduced in human tissue through breathing air, food chain and human skin. They can cause damage to the nervous system and internal organs. In the present study, sixty street dust samples were collected from the central area of Tehran and were digested in the laboratory to determine the content of Zn, Ni, Cd, Cr, Cu and Pb, using inductively coupled plasma optical emission spectrometry (ICP-OES). The level of contamination with the analyzed metals was determined according to the following indices: geo-accumulation index (I _geo), enrichment factor (EF), pollution index (PI), integrated pollution index (IPI) and potential ecological risk index (RI). The average concentration of heavy metals found was in the order of Zn > Cu > Pb > Ni > Cr > Cd. The average I _geo values for Cd, Cr, Cu, Ni, Pb and Zn were 1.53, ?1.88, 2.68, ?0.67, 1.62 and 2.70, respectively. Among the investigated heavy metals, zinc and copper had the maximum average EF values and were placed into the “very severe enrichment” class. Potential ecological risk factor (E _r) also indicated that Cd had the highest risk, and it was classified as of considerable potential ecological risk. Therefore, it is necessary to pay more attention to the appearance of Cd in the human environment. The calculated potential ecological risk index values also illustrated that the street dust samples presented a “moderate ecological risk.” The calculated IPI values showed that the pollution levels of the street dust samples ranged from high to extremely high.     

Seismic risk assessment of a steel building supported on helical pile groups

Acta Geotechnica - Designing structures to be the least vulnerable within earthquake-prone areas is a serious challenge for structural engineers. One common and useful tool that structural...     

Land subsidence risk assessment using GIS fuzzy logic spatial modeling in Varamin aquifer,Iran

GeoJournal - The extent of the subsidence and the consequents damage to most of the residential and populated areas of Iran have made this phenomenon one of the most important natural hazards after...     

Health risk assessment of nitrate exposure in groundwater of rural areas of Gonabad and Bajestan,Iran

Prolonged exposure to excessive levels of nitrate through drinking water is a potential risk for human health. The current research reports the analytical results and associated health risk for water quality in term of nitrate in 39 groundwater samples during January 2018 in rural areas of Gonabad and Bajestan, Iran. Nitrate concentrations ranged from 1.8 to 82.2 and from 5.5 to 84.3 mg/L for Gonabad and Bajestan, respectively. In this work, the potential risk to human health was determined using the hazard quotient (HQ) for three age groups including adults, children and infants. Comparison of HQs among the 39 sampling sites showed that the rural areas in Bajestan had higher HQs than Gonabad. Among the studied groups, infants exposed to a higher risk than children and adults. The results also indicated that the health of individuals from nitrate exposure in most of the groundwater studied was not acceptable and most of the consumers were in danger from current nitrate concentrations. Therefore, there is an urgent need for enforcing effective plans to improve groundwater quality and to better manage and control probable nitrate contaminated sources.     

西气东输管道通过长江三江口方案工程地质条件评价

从工程地质及水文地质角度,对西气东输管道通过长江三江口方案适宜性进行了研究。指出了方案有利的环境地质条件及存在的主要环境地质问题,提出了相应的对策,为优化管道过长江设计、施工方案提供了地质依据。     

Geotechnical assessment of a landslide along a natural gas pipeline for possible remediations (Karacabey-Turkey)

A new natural gas pipeline with a 0.90-m diameter is under construction to provide a gas connection between Turkey and Greece as well as to create a gas ring for southern Europe. The new pipeline route lies next to an existing small diameter gas pipeline broken by a landslide that occurred in February 2006 near Karacabey (Bursa). Although the existing pipeline has been temporarily repaired, either the pipeline route should be relocated or the landslide should be stabilized. The geological survey conducted in the study area reveals that relocation is not feasible due to the existence of other landslides in close vicinity to the site. In order to investigate the causes of the landslide and to suggest possible remedial measures, geotechnical investigations including surface geological mapping, trial pitting, drilling with field tests, inclinometer measurements, laboratory testing, and limit equilibrium analyses were conducted. The investigation revealed that the unconsolidated clayey soil slid on claystone along a non-circular failure surface. Based on the gathered data, possible remedial measures including partial removal of landslide material and construction of toe buttresses, slope flattening, lowering the pipeline, and surface drainage systems were evaluated. These are suggested to prevent the reactivation of the landslide, and thus to establish a safe route for both the existing and the new pipelines.     

Seismic risk assessment of buildings in urban areas: a case study for Denizli,Turkey

This study aims to carry out a seismic risk assessment for a typical mid-size city based on building inventory from a field study. Contributions were made to existing loss estimation methods for buildings. In particular, a procedure was introduced to estimate the seismic quality of buildings using a scoring scheme for the effective parameters in seismic behavior. Denizli, a typical mid-size city in Turkey, was used as a case study. The building inventory was conducted by trained observers in a selected region of Denizli that had the potential to be damaged from expected future earthquakes according to geological and geotechnical studies. Parameters that are known to have some effect on the seismic performance of the buildings during past earthquakes were collected during the inventory studies. The inventory includes data of about 3,466 buildings on 4,226 parcels. The evaluation of inventory data provided information about the distribution of building stock according to structural system, construction year, and vertical and plan irregularities. The inventory data and the proposed procedure were used to assess the building damage, and to determine casualty and shelter needs during the M6.3 and 7.0 scenario earthquakes, representing the most probable and maximum earthquakes in Denizli, respectively. The damage assessment and loss studies showed that significant casualties and economic losses can be expected in future earthquakes. Seismic risk assessment of reinforced concrete buildings also revealed the priorities among building groups. The vulnerability in decreasing order is: (1) buildings with 6 or more stories, (2) pre-1975 constructed buildings, and (3) buildings with 3–5 stories. The future studies for evaluating and reducing seismic risk for buildings should follow this priority order. All data of inventory, damage, and loss estimates were assembled in a Geographical Information System (GIS) database.