A method for quick assessment of earthquake-triggered landslide hazards: a case study of the Mw6.1 2014 Ludian,China earthquake

Rapid assessment of the distribution of earthquake-triggered landslides is an important component of effective disaster mitigation. The effort should be based on both seismic landslide susceptibility and the ground shaking intensity, which is usually measured by peak ground acceleration (PGA). In this paper, we address this issue by analyzing data from the Mw6.1 2014 Ludian, China earthquake. The Newmark method of rigid-block modeling was applied to calculate the critical acceleration of slopes in the study area, which serve as measurement of slope stability under seismic load. The assessment of earthquake-triggered landslide hazard was conducted by comparing these critical accelerations with the distribution of known PGA values. The study area was classified into zones of five levels of landslide hazard: high, moderate high, moderate, light, and very light. Comparison shows that the resulting landslide hazard zones agree with the actual distribution of earthquake-triggered landslides. Nearly 70% of landslides are located in areas of high and moderately high hazard, which occupy only 17% of the study region. This paper demonstrates that using PGA, combined with the analysis of seismic landslide susceptibility, allows a reliable assessment of earthquake-triggered landslides hazards. This easy-operation mapping method is expected to be helpful in emergency preparedness planning, as well as in seismic landslide hazard zoning.

     

Evaluation of dynamic stability and analysis of reinforcement measures of a landslide under seismic action: a case study on the Yanyangcun landslide

Bulletin of Engineering Geology and the Environment - Earthquakes are a major landslide trigger, and evaluation of the dynamic stability of landslides under seismic action is very important. The...     

Impact of slope stability changes on landslide activity near the epicenter of the 2008 Wenchuan Ms8.0 earthquake,China

Bulletin of Engineering Geology and the Environment - Strong earthquakes in mountainous regions can trigger massive landslides, and not just during the period of shaking. This study uses a time...     

Formation and evolution of a successive landslide dam by the erosion of river: a case study of the Gendakan landslide dam on the Lancang River,China

Bulletin of Engineering Geology and the Environment - A landslide dam located on the Lancang River in Southwest China was used as a case to study the landslide formation and evolution process...     

The mechanisms of a loess landslide triggered by diversion-based irrigation: a case study of the South Jingyang Platform,China

Bulletin of Engineering Geology and the Environment - Continuous use of diversion-based irrigation has been associated with an increase in the frequency of loess landslides on the South Jingyang...     

Effect of locally accumulated crushed stone soil on the infiltration of intense rainfall: a case study on the reactivation of an old deep landslide deposit

An old landslide deposit situated in Deqin County, Yunnan Province, China, was used to investigate the effects of local accumulation of crushed stone soil on infiltration of intense rainfall. This study considers the infiltration process and landslide stability using finite-element method (FEM)-based models and a physical experimental model. The results show that reactivation of the old landslide was triggered by intense rainfall that occurred on 7–9 October 2012. The crushed stone soil played a key role in the rapid infiltration of rainfall deep into the landslide deposit. Accumulated rainfall and runoff water caused the formation of high pore water pressure in the crushed stone soil, which induced higher infiltration of the surrounding soil due to the higher gradient. The original slip zone was another key factor, as infiltrated water accumulated at the slip zone and form a high pore water pressure due to the lower permeability of the slip zone. The high pore water pressure that formed at the slip zone was the main factor triggering reactivation of the landslide during the rainfall.

     

Combining geophysical methods,drilling, and monitoring techniques to investigate carbonaceous shale landslides along a railway line: a case study on Jiheng Railway,China

Bulletin of Engineering Geology and the Environment - Landslides are common occurrences along Chinese rail routes. Accordingly, the accurate determination of sliding-surface locations and the...     

Influence of faulting on a mine shaft—a case study: part I—Background and instrumentation

The impact of geological structures on the stability of underground infrastructures is well recognised. Moreover, the influence of major geological structures such as faults, becomes critical when the stability of underground infrastructures which are essential for mine production, are threatened. The X41 shaft is the man and supply shaft at the Copper Mine, at Mount Isa, Australia. Here, there has been observed evidence of degradation manifested by the development of cracks in the shaft concrete lining since the early nineties. In addition, the shaft steel structure is being deformed and needs regular and meticulous maintenance. The shaft degradation has been attributed to the presence of two major geological structures, the W41 and W42 faults, which intersect the shaft in two distinct locations.This paper presents a case study whereby the causes of shaft degradation were examined. The influence of faulting and mining sequence on the stability of the main mine shaft were investigated by means of field investigations and numerical modelling. This paper concentrates on the field investigation performed as part I of this project. It provides a review of work done prior to this study and exposes the past field monitoring practices and those that were implemented to characterise the observed displacement in the X41 shaft.     

GIS-based landslide hazard zonation: a case study from the Parwanoo area,Lesser and Outer Himalaya,H.P., India

GIS-based landslide hazard zonation has been carried out for a tectonically active region of the Himalayas, which is under pressure for rapid economic development. Thematic layers of slope, fault, geology, land use, flow accumulation, drainage and roads were prepared based on topographic maps, satellite imagery, published geological maps and ground truth. Five classes of landslide hazard were identified; 24% of the total area falls into the Very high or High hazard zones where 54% of the observed landslides were recorded.      

Influence of fines content on liquefaction from a critical state framework: the Christchurch earthquake case study

Bulletin of Engineering Geology and the Environment - In earthquake engineering practice, the liquefaction potential of soils is commonly evaluated through simplified procedures. These approaches...     

Modification of rock stress factor in the stability graph method: a case study at the Alhada Lead-Zinc Mine in Inner Mongolia,China

Bulletin of Engineering Geology and the Environment - The stability graph is an empirical approach to predicting stope performance based on the geometric dimensions of stopes and the geotechnical...     

Ground cracks development and characteristics of strata movement under fast excavation: a case study at Bulianta coal mine,China

Bulletin of Engineering Geology and the Environment - Field examples of fast exploitation from underground coal seams in Bulianta mines, China, show that unexpected developmental rules of...     

广西忻城与云南纳楼土司衙署建筑初探

从建筑形制和建筑风格的角度,对广西忻城县莫氏土司和云南建水县纳楼土司的衙署进行分析,归纳总结两地土司衙署的异同,探讨影响衙署形制和风格的因素,对两地土司衙署建筑做出新的判断。     

Site response analysis for the seismic improvement of a historical and monumental building: the case study of Augusta Hangar

Bulletin of Engineering Geology and the Environment - Eastern Sicily is very rich of historical buildings, but at the same time is one of the most seismically active areas of Italy. In particular,...     

Design of anchorage and assessment of the stability of openings in silty, sandy limestone: a case study in Turkey

This study presents a procedure for the design of anchorage and for the assessment of the stability of openings in silty, sandy limestone through investigating the geotechnical problems of the Hasankeyf historical settlement area in southeastern Turkey, of which a good portion will stay below the reservoir of the proposed Ilısu dam. Rock mass characterization was performed. The RMR and GSI methods were utilized for rock mass classification. The RocLab software was used to determine the shear strength parameters and the geomechanical properties of the rock mass according to the GSI method. The cohesion and angle of internal friction of the rock mass was determined as 257 kPa and 52°, respectively. A back analysis was applied to a structurally controlled planar failure block supporting one of the prominent historical structures in the area to determine the shear strength parameter pairs that satisfy limit equilibrium along the sliding surface of the planar block. A sensitivity analysis of the most likely shear strength pairs satisfying limit equilibrium was performed as a function of reservoir water condition (i.e., rapid drawdown, dry and wet reservoir condition) and the expected earthquake generated peak horizontal ground acceleration coefficient. The results of the back analysis led to a cohesion of 161 kPa and an angle of internal friction of 40° along the failure surface of the planar block. A limit equilibrium sensitivity analysis of the unstable rock block was performed as a function of the water condition of the reservoir, expected earthquake generated peak horizontal ground acceleration coefficient and rock anchor inclination angle. The minimum anchor force required for the stabilization of the planar block was calculated for a rapid drawdown condition as 4000 kN/m. A total of fifty six (56) rock anchors, each with a service load capacity of 1000 kN and spaced at 1 m are recommended for stability. Finite element analysis was utilized to analyze the collapse of some of the roofs of the adjacent man-made cave dwellings carved in rock due to insufficient pillar thicknesses and to determine the minimum pillar thickness required between adjacent caves in the region for stability. Nine different pillar thicknesses ranging from 0.1 to 0.93 m were analyzed. The stages included in the finite element analysis of the caves were: (a) gravity loading due to the thickness of the overburden followed by applying the far field horizontal stresses and inserting the planar block fracture; (b) excavating the caves in stressed rock assuming full face excavation and (c) applying a uniform traction load. The results of the finite element analysis led to a recommendation to apply a steel arch support to one of the adjacent caves located at Hasankeyf in case the wall thickness was less than or equal to 0.5 m.     

Modification of the BQ system based on the Lugeon value and RQD: a case study from the Maerdang hydropower station,China

Bulletin of Engineering Geology and the Environment - Current rock mass quality classification methods include the rock mass rating (RMR), the Q system, the geological strength index (GSI) and the...     

Comprehensive concept planning of urban greening based on ecological principles: a case study in Beijing, China

Greenspace is an important part of complex urban ecosystems and provides significant ecosystem services. It benefits urban communities environmentally, esthetically, recreationally and economically. Beijing Province is in north of China, and has a total area of 16,807.8 km² and a population of about 13.8 million. This paper aims to develop a comprehensive conceptual framework for urban greening of Beijing Province based on landscape ecological principles. It attempts to answer how to establish an urban greening plan at the regional, city and neighborhood levels to achieve long-term sustainability. At the regional level, a big natural and semi-natural forest area in the northwest and an ecological buffer belt in the southeast are planned to protect the environmental quality of Beijing and provide habitats for wildlife. At the city level, a green network system of green wedges, parks and green corridors has been proposed. This green network helps to limit future urban expansion, improve urban environmental quality and serve as habitats and migration routes for wildlife. At the neighborhood level, green extensions and connections of riverside greenway, road greenway, parks and vertical greening permeate into the built-up areas. They provide open space close to residential areas and offer places for recreation. This three-level green system constitutes an integrated ecological network for urban sustainable development of Beijing. For future development of Beijing, urban parks, forestry, agriculture, water and infrastructure should be planned and designed in an integrated way. After this greenspace plan is legislated and completely realized, Beijing will develop an interconnected and integrated network of urban greenspaces. It has the prospect of achieving the aim of “Green Olympic City 2008” and the long-term goal of developing Beijing towards an “Eco-City”.