scholarly journals Back analysis for circular or elliptical tunnel in isotropic and anisotropic rock medium based on exact elastic solutions.

1991 ◽  
pp. 1-8
Author(s):  
Ken-ichi HIRASIMA ◽  
Tetsutaro KAWAKAMI ◽  
Toshio FUJIWARA ◽  
Yukio YAMASHITA
Keyword(s):  
Back Analysis ◽  
Anisotropic Rock

scholarly journals Optimization of Measuring Points Layout around a Tunnel in the Transversely Isotropic Rock Mass

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Zhizeng Zhang ◽  
Yongtao Li ◽  
Weili Yang ◽  
Shunchuan Wu ◽  
Xiaoli Liu ◽  
...  
Keyword(s):  
Rock Mass ◽  
Lateral Pressure ◽  
Back Analysis ◽  
Transversely Isotropic ◽  
Anisotropic Rock ◽  
Maximum Displacement ◽  
Transversely Isotropic Rock ◽  
Isotropic Rock ◽  
Anisotropic Rock Mass ◽  
Principle Of Maximum

The arrangement of measuring points has a great impact on the uniqueness and accuracy of the back analysis of displacement. To explore the arrangement method of measuring points in the anisotropic rock mass, the principle of maximum displacement is applied to study the optimization of measuring points layout around a tunnel in the transversely isotropic rock mass. Firstly, the criterion of maximum displacement is deduced. Secondly, the variations of displacement with angle and radius are analyzed, respectively, and two key lateral pressure coefficients are obtained. Thirdly, some principles of measuring points arrangement are summarized according to the criterion of maximum displacement. Finally, an example is given to prove the correctness of these principles. These principles can be used to guide the arrangement of displacement measuring points in the transversely isotropic rock mass, especially suitable for shaft excavation in horizontal sedimentary rock.

Back-analysis of Donghekou landslide using improved DDA considering joint roughness degradation

Landslides ◽  
2021 ◽  
Author(s):  
Jinmei Wang ◽  
Yingbin Zhang ◽  
Yanlong Chen ◽  
Qingdong Wang ◽  
Chenlin Xiang ◽  
...  
Keyword(s):  
Back Analysis ◽  
Joint Roughness

Back-Analysis of a Debris Slope through Numerical Methods and Field Observations of Slope Displacements

2021 ◽  
Author(s):  
Koushik Pandit ◽  
Mahendra Singh ◽  
Swati Sharma ◽  
Har Amrit Singh Sandhu ◽  
Jagdish Prasad Sahoo
Keyword(s):  
Numerical Methods ◽  
Back Analysis ◽  
Field Observations ◽  
Debris Slope

Thematic mapping of the abandoned mining hazard: a pilot study for the South Wales Coalfield

1987 ◽  
Vol 4 (1) ◽  
pp. 255-268 ◽  
Author(s):  
I. Statham ◽  
C. Golightly ◽  
G. Treharne
Keyword(s):  
Back Analysis ◽  
Ground Surface ◽  
Historical Record ◽  
Mining Subsidence ◽  
Present Condition ◽  
Opencast Mining ◽  
The South ◽  
Mining Sites ◽  
South Wales ◽  
Method Of Production

AbstractThe Department of the Environment and the Welsh Office jointly sponsored a South Wales Desk Study into the feasibility of producing thematic maps of the Mining subsidence risk for planners. A method was to be developed and tested for a 25 km2 Pilot Area centred on Ebbw Vale.The study was started by collecting geological and mining data for the Pilot Area and compiling this information on a map. It was then intended to prepare the mining subsidence map from this map by back analysing subsidence incidents to determine the hazardous areas. This simple approach could not be followed for two reasons. First, the record of mining was incomplete and it was therefore necessary to define ‘worked’ seams and areas from the total historical record and not only from the surviving mine plans. Secondly, insufficient subsidence incidents were discovered in the Pilot Area to carry out meaningful back analysis.The study was extended to collect all readily available records of subsidence incidents throughout the Coalfield. A total of 388 were traced, mainly dating from 1960. About threequarters were collapses through superficial materials and were either close to the outcrop or above mine entries, the remaining 25% propagated to the ground surface through rock. The upper limit of migration was typically 8 times the extracted height where the dip was shallow, incrasing to as much as 18 times for steep dips. Selected grout contracts and opencast mining sites were also examined to gain information on the present condition of old workings and to study the ‘reputations’ of the various seams for voids.The results of the coalfield study were applied to the Pilot Area to produce a 1:10 000 scale Development Advice Map, ‘Mining Subsidence for use by developers and planners’. The map is zoned to show areas where specialist advice is necessary to support a planning application and it also shows all mine entries traced by the desk study. The method of production is general for the South Wales Coalfield and further maps could be prepared, using the Coalfield Study, quickly and cheaply.

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