Assessment of rock slope stability by probabilistic-based Slope Stability Probability Classification method along highway cut slopes in Adilcevaz-Bitlis (Turkey)

Rock slope stability is of great concern along highway routes as stability problems on cut slopes may cause fatal events as well as loss of property. In rock slope engineering, stability evaluations are commonly performed by means of analytical or numerical analyses, principally considering the factor of safety concept. As a matter of fact, the probabilistic assessment of slope stability is progressively getting popularity due to difficulties in assigning the most appropriate values to design parameters in analytical or numerical methods. Additionally, the effect of heterogeneities in rock masses and discontinuities on the analysis results is minimized through the probabilistic concept. In this study, slope stability of high and steep sedimentary rock cut slopes along a state highway in Adilcevaz-Bitlis (Turkey) was evaluated on the basis of probabilistic approach using the Slope Stability Probability Classification (SSPC) system. The probabilistic assessment indicates major slope stability problems because of discontinuity controlled and discontinuity orientation independent mass movements. Almost all studied cut slopes suffer from orientation-independent stability problems with very low stability probabilities. Additionally, the probability of planar and toppling failures is significantly high with respect to the SSPC system. The stability problems along the investigated rock slopes were also verified by field reconnaissance. Remedial measures such as slope re-design and reinforcement at the studied locations should be taken to prevent hazardous events along the highway. On the other hand, the probabilistic approach may be a useful tool during rock slope engineering to overcome numerous uncertainties when probabilistic and analytic results are compared.     

世界地质公园--黄山

黄山位于安徽省南部,19913年,联合国教科文组织将黄山以文化和自然遗产双重身分列入《世界遗产名录》。黄山面积1200平方公里．景区范围154平方公里,有自然景色400处。景区群山耸立．峰峰相连,七十二峰捧三星：莲花峰、天都峰、光明顶、莲花峰海拔高度1860米．宛若一朵盛开的芙蓉：天都峰高1810米．传说中神仙居住的地方;光明顶高1840米,是观云海看日出的绝好去处。     

高速公路工程建设用地勘测定界实用方法

建设用地勘测定界的目的,主要是为国土资源管理部门对工程的用地规模,比照国家行业用地标准,审查是否符合要求.其次,所界定的县(市)、乡、村的用地面积以及不同的地类,作为给予被征地人补偿和占用耕地后进行补充耕地面积的依据.建设用地勘界工作的工期长短将直接影响整个工程的建设速度和质量精度,将影响对被征地人进行合理补偿的落实问题.可见建设用地勘界成果的质量和工期的长短在整个工程建设中也是同样重要.     

IMPACT OF ROAD CONSTRUCTION ON VEGETATION ALONGSIDE QINGHAI-XIZANG HIGHWAY AND RAILWAY

Based on the field investigation in August 2001 and August 2002, digital China Vegetation Map in 2001 and Qinghai-Xizang(Tibet) Plateau Vegetation Regionalization Map in 1996, vegetation characteristics along two sides of Qinghai-Xizang highway and railway are studied in this paper. Meanwhile, the impact of Qinghai-Xizang highway and railway constructions on the vegetation types are analyzed using ARCVIEW. ARC/1NFO and PATCH ANALYSIS. It was found that: 1) Qinghai-Xizang highway and railway span 9 latitudes, 12 longitudes and 6 physical geographic regions (East Qinghai and Qilian mountain steppe region, Qaidam mountain desert region,South Qinghai-Xizang alpine meadow steppe region. Qiangtang alpine steppe region, Golog-Nagqu alpine shrubmeadow region and South Xizang mountain shrub steppe region); 2) the construction of Qinghai-Xizang highway and railway destroyed natural vegetation and landscape, especially in 50m-wide buffer regions along both sides of the roads, it was estimated that the net primary productivity deceased by about 30 504.62t/a and the gross biomass deceased by 432 919.25-1 436 104.3t. The losing primary productivity accounted for 5.70% of the annual primary productivity within lkm-wide buffer regions (535 005.07-535 740.11t/a), and only 0.80%-0.89% of that within 10km-wide buffer regions (3 408 950.45-3 810 480.92t/a). The losing gross biomass was about 9.47%-17.06% of the gross biomass within lkm-wide buffer regions (7 502 971.85-25 488 342.71t), and only 1.47%-2.94% of that within 10km-wide buffer regions (43 615 065.35-164 150 665.37t).     

Recent climate trends on the northern slopes of the Tianshan Mountains, Xinjiang, China

In arid regions, mountains fulfill important ecological and economic functions for the surrounding lowlands. In the scenario of global warming, mountain ecosystems change rapidly, especially in the arid region of northwestern China. This paper provides an assessment of the changes in temperature and precipitation in the historical records of climate on the northern slopes of the eastern Tianshan Mountains. A Mann-Kendall nonparametric trend and Sen＇s tests are employed to analyze the interannual changes and innerannual variability in temperature and precipitatiofi in the regions of low to high altitude. The present study finds that the largest increases in annual temperature are observed at stations in the low altitude regions. The significant increasing trends in temperature tend to occur mainly in late winter and early spring at stations from middle to high altitude, but in summer and autumn at stations of low altitudes. The increasing trends in annual precipitation are found from the middle to high altitude areas, but decreasing trends are found in the low altitude areas. The significant increasing trends in precipitation occur mostly in winter and earlier spring at stations from the middle to high altitudes, while the increasing and decreasing trend coexists at stations of low altitude with most of the significant trend changes occurring in March, June and August.     

山区公路软基病害研究

随着高等级公路建设规模的扩大，山区公路所面临的路基病害特别是软土路基病害问题也逐渐增多。结合对陕南勉(县)一宁(强)高速公路工程实例分析，对山区软土成因及其特性进行了初步分析，认为山区软土属以坡洪积、湖积和冲积为主的软土，也有少量是由坡残积物堆积而形成。山区软土的特殊性表现在成分的复杂性、分布的不均匀性、隐蔽性和物理力学性质的特殊性。根据其特性以及中国山区公路软基普遍存在的病害问题，总结了山区公路软基的主要病害类型为剪切拉裂破坏、浸水沉陷破坏、剥蚀坍塌破坏、推挤滑动破坏。还提出了相应的软基处理方法及建议。     

公路建设生态环评编制问题分析

从评价工作等级、评价范围等方面明确公路建设生态环评编制中易忽略的几个问题，籍为提高环评大纲及报告书编制质量有所裨益。     

Methods for the construction of DEMs of artificial slopes considering morphological features and semantic information

As human activities increase,artificially modified terrain is increasingly widely distributed in road,hydrological,and urban construction.Artificially modified ...     

基于可靠度理论的黄土高边坡优化设计

对黄土高边坡进行可靠性分析，应用数学原理和优化原理，建立了黄土高边坡的优化模型，对铜黄一级公路黄土高边坡进行分析验证。结果表明，该方法计算的结果与实际较接近．应用中易操作。     

THE ORIGIN AND CHARACTERISTICS OF THE GLACIAL DEBRIS FLOW IN THE DUKU HIGHWAY OF TIANSHAN MOUNTAINS，

ＴＨＥＯＲＩＧＩＮＡＮＤＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＯＦＴＨＥＧＬＡＣＩＡＬＤＥＢＲＩＳＦＬＯＷＩＮＴＨＥＤＵＫＵＨＩＧＨＷＡＹＯＦＴＩＡＮＳＨＡＮＭＯＵＮＴＡＩＮＳ，ＣＨＩＮＡ￥ＸｉｏｎｇＨｅｉｇａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ...     

Evolution model and failure mechanisms of rainfall-induced cracked red clay slopes:insights from Xinshao County,China

Red clay landslides are widely distributed worldwide, resulting in severe loss of life and property. Although rainfall-induced red clay slopes have received extensive attention, the role of cracks in the evolutionary process of red clay slopes and their connection to failure mechanisms is still poorly understood. A comprehensive approach integrating field investigation, laboratory tests, and numerical simulations was conducted to study the 168 red clay landslides in Xinshao County, China. The re...     

Reference evapotranspiration concentration and its relationship with precipitation concentration at southern and northern slopes of Tianshan Mountains,China

The investigation of concentration characteristics of reference evapotranspiration(ETref) is important for water resources management. The concentration index(CI), concentration degree(CD) and concentration period(CP) are used to investigate the concentration characteristics of ETref and the relationship between ETref concentration and precipitation concentration at sub-monthly timescale based on the daily climatic variables from 1966 to 2015 in 27 meteorological stations at the southern and northern slopes of Tianshan Mountains in China. It was found that the CI of ETref is about 0.40 and less concentrated than precipitation in the study area. At the southern slope, the maximum ETref appears in late June and is earlier than the maximum precipitation(early July), ETref distributes more equally than precipitation, and the CI, CD and CP of these two variables do not show significant change based on the Mann–Kendall test. At the northern slope, both the maximum ETref and precipitation appear in early July, and ETref is more dispersed than precipitation. During the study period, the maximum ETref at the northern slope tends to appear earlier due to the impacts of wind speed, relative humidity, sunshine duration, and air temperature. ETref concentration does not match the precipitation concentration in the study area, particularly at the southern slope. The mismatch between ETref and precipitation concentration within a year reveals the water resources pressure on environmental, social and economic sustainability in the study area.     

Study on preventing frost heave methods for highway foundation in seasonal frozen area

In order to resolve the frost-heave problem of highway foundation, firstly, the author discussed the law to frost heave of highway roadbed and gave an analysis on its influencing factors, such as soil, water and temperature. Meanwhile, sand clay and silt are given a classification according to frost heave ratio. Secondly, the roadbed frozen damage shows to frost heave and froze boiling based on the frost heave law and its influencing factors. In addition, taking some highway as an example and some principle suggestion was given through the theory on providing frostbite methods for highway foundation frost heave in seasonal frozen area. Specially, an effective method, STYROFOAM extruded polystyrene foam was introduced.     

Study on preventing frost heave methods for highway foundation in seasonal frozen area

In order to resolve the frost-heave problem of highway foundation,firstly,the author discussed the law to frost heave of highway roadbed and gave an analysis on its influencing factors,such as soil,water and temperature.Meanwhile,sand clay and silt are given a classification according to frost heave ratio.Secondly,the roadbed frozen damage shows to frost heave and froze boiling based on the frost heave law and its influencing factors.In addition,taking some highway as an example and some principle suggestion was given through the theory on providing frostbite methods for highway foundation frost heave in seasonal frozen area.Specially,an effective method,STYROFOAM extruded polystyrene foam was introduced.     

COMPARISON OF QUATERNARY DEPOSIT ENVIRONMENT AMONG LUSHAN,HUANGSHAN AND TIANMU MOUNTAINS

TheQuaternalypaleo--environmentoftheLushan,HuangshanandTianmumountainsisasignificantacademicproblemtowhichmuchattentionhasbeenpaidbymanyresearchersingeosciencecircle.Manyscholarshavestudiedtheproblemandgotalotofachivementsoverthepastyears(Lee,1933;Lee,1936;Lee,1947;Ren,1953;Huang,1963;Li,1974;Shi,1989).HOWever,identicalviewsandconclusionshavenotbeenreachedyetuptillnow,especiallylackingofcomprehensivestudyforsedimentsintheseregions.Inrecentyears,applyingsedimentalcomprehensiveindexgotfromv…     

Stability of submarine slopes in the northern South China Sea: a numerical approach

Submarine landslides occur frequently on most continental margins. They are effective mechanisms of sediment transfer but also a geological hazard to seafloor installations. In this paper, submarine slope stability is evaluated using a 2D limit equilibrium method. Considerations of slope, sediment, and triggering force on the factor of safety (FOS) were calculated in drained and undrained (Φ=0) cases. Results show that submarine slopes are stable when the slope is <16° under static conditions and without a weak interlayer. With a weak interlayer, slopes are stable at <18° in the drained case and at <9° in the undrained case. Earthquake loading can drastically reduce the shear strength of sediment with increased pore water pressure. The slope became unstable at >13° with earthquake peak ground acceleration (PGA) of 0.5 g; whereas with a weak layer, a PGA of 0.2 g could trigger instability at slopes >10°, and >3° for PGA of 0.5 g. The northern slope of the South China Sea is geomorphologically stable under static conditions. However, because of the possibility of high PGA at the eastern margin of the South China Sea, submarine slides are likely on the Taiwan Bank slope and eastern part of the Dongsha slope. Therefore, submarine slides recognized in seismic profiles on the Taiwan Bank slope would be triggered by an earthquake, the most important factor for triggering submarine slides on the northern slope of the South China Sea. Considering the distribution of PGA, we consider the northern slope of the South China Sea to be stable, excluding the Taiwan Bank slope, which is tectonically active.     

东天山黄山岩体的侵位时代及其地质意义

东天山黄山-镜儿泉地区分布有众多镁铁质-超镁铁质岩体,岩体成群成带分布,受区域性韧性剪切带和断裂构造控
制。为进一步确定黄山-镜儿泉基性-超基性岩带的侵位时代、成因和大地构造背景,对选自黄山岩体辉长岩相中单颗粒锆石进
行了LA-ICP-MSU-Pb定年研究,将其结果[(284.5±2.5)Ma]与黄山岩体和黄山-镜儿泉一带其他基性-超基性岩中已有的定
年成果进行了对比,并结合近年来该区研究成果,分析得到黄山辉长岩侵位于晚石炭世-早二叠世,此时正值东天山后碰撞大规
模岩浆侵位和成矿时期。黄山镁铁质-超镁铁质岩带形成于后碰撞的伸展构造环境。      

Some conifers from Aptian in Yanbian area of jilin,Northeast China

Some well-preserved conifer leafy shoots and female cones from the Lower Cretaceous Changcai Formation near Fudong of Helong, eastern Jilin, Northeast China are studied. Based on gross morphological and cuticular study, a new species, Elatides helongensis Sun et Zhao (sp. nov.) is described systematically. The new species is characterized by persistent, linear or slightly falcate leaves with obtusely acute apex, attached helically on the shoots. Female cones of the new species are terminal and oval, composed of persistent helically-arranged rhomboidal scales and erect seeds. One erect seed is growing on each scale. Leaf cuticles are hypostomatic. Monocylic stomata are ellipse, composed of 2 sunken guard cells and 4-8 subsidiary cells. Moreover, the cuticles of a young female cone of Pityostrobus yingchengensis Yang are described for the first time.     

Survey on PCDDs and PCDFs in sediments and soils in Ya-Er Lake area, China

INTRODUCTIONOverthepastseveralycars,considerableinteffethasbocenteIdontheenvir0nmentalbehaviouroftoxicandpersistritcomP0undssuchashalogenatalaromat-ies,inparticularthepolychiorinataldibopdioxins(PCDDe)andpolydil0rinateddi~fUtansrpCDFs).ManyofthesecomPounds,espedllythosewithahighdegere0fchiorinesubstitution,arehighlylipophiliccontawhnantSwithlowWhtersolubility,highre-sistancet0chdricaltransformationsandlowwhcrobiologhaldegradatfonpeatnnann,l988,Bromanetal.,l989,Hites,l990)whichexplain…     

Assessing the influence of highway and high-speed railway construction on local climate using Landsat images in karst areas

Large-scale transportation infrastructure construction in ecologically vulnerable areas such as the karst region of Southwest China requires estimation method for better project design. This research was carried out on a four-lane highway(the Guilin-Guiyang highway, G76) and a two-lane highspeed railway(the Guilin-Guiyang high-speed railway,GGHSR) in karst areas in Guizhou and Guangxi provinces. The highway and high-speed railway were constructed in the 2010 s and covered by Landsat images whose multispectral information could be used for research purposes. In this study, the severity of the impact and the CO_2 emissions from the G76 and GGHSR construction were evaluated. Landsat images and field meteorological measurements were applied to calculate the surface functional parameters(surface temperature and surface wetness) and heat fluxes(latent, sensible and ground heat flux) before and during the highway and high-speed railway construction; the amount of CO_2 emissions during the G76 and GGHSR construction were determined by using budget sheets, which record the detail consumptions of materials and energy. The results showed that the decrease of water evaporation from the highway and high-speed railway construction can reach up to 26.4 m~3 and 20.1 m~3 per kilometer, which corresponds to an average decrease in the vegetation cooling effect of 18.0 MWh per day per highway kilometer and 13.7 MWh per day per high-speed railway kilometer, respectively. At the meantime, the average CO_2 emission densities from the G76 and GGHSR construction can reach up to 24813.7 and 36921.1 t/km, respectively. This study implied that extensive line constructions have a significant impact on the local climate and the energy balance, and it is evident that selecting and planting appropriate plant species can compensate for the adverse effects of line constructions in karst mountain regions.