• Journal of the Korean Society for Railway
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• v.9 no.1 s.32
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• pp.110-117
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• 2006

Boulder detection methods and its compensation is discussed with consideration of boulder conditions in soft ground tunneling by shielded TBM. For analysis of proper compensation methods for boulder obstruction, its removal costs and cases on eight projects are presented. Compensation for boulder obstruction removal by volume or weight is not practical for most tunneling situation, but compensation by crew time is probably the most equitable method. If boulders are anticipated on project, boulder removal plan must be considered with proper equipment selection.

• Journal of the Korean association of regional geographers
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• v.6 no.2
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• pp.71-82
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• 2000

The purpose of this paper is to clarify geomorphic features and development on the boulder stream of granitoid in Korea. Considering the purpose and the method of this paper, three boulder streams are selected : Biseulsan(Mt. Biseul) boulder stream (Daegu city), Maneosan (Mt. Maneo) boulder stream(Gyeongnam province), Geumjeongsan(Mt. Geumjeong) boulder stream (Busan city). The boulder streams mentioned above are bigger in scale and more typical in shape than any other ones in the Korean Peninsula. The main results are summarized as follows. 1. The following are the main features of the boulder streams morphology : the mean gradient is $3{\sim}25^{\circ}$, the longer axes of the component boulders within the deposits averaged about 2m in length, the shapes of the component boulders may be both subangular and subrounded features. 2. The formation of the component boulders is associated with deep weathering of granitoid under warm humid conditions, and the downward movement of boulders occurred by solifluction and frost creep under periglacial conditions. 3. The geomorphic development stage of the boulder streams may be classified into four stages. These boulder streams come under fossil landform stage, the 4th stage ; evidence provided by lichens and weathering features indicate inactive or fossil landform. 4. In generally, boulder streams are well developed on shallow valley floors.

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.59-59
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• 2002

• 한국초전도학회:학술대회논문집
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• v.12
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• pp.18-18
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• 2002

• Geotechnical Engineering
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• v.28 no.2
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• pp.20-26
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• 2012

• Magazine of the Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.2-6
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• 2019

• Magazine of the Korean Society of Agricultural Engineers
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• v.59 no.3
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• pp.43-49
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• 2017

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.996-1008
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• 2016

Effects of substrate types (bedrock and boulder habitat) on the community structures of benthic biota (macroalgae, macrobenthos) were monthly examined at Sinheung in Jeju Island, Korea, from Feb. to Nov. 2015. Species diversity of seaweeds and macrobenthos was greater at bedrock sites with 57 and 102 species than at boulder sites having 42 seaweeds and 67 macrobenthos. Average annual biomass of seaweeds was $1,601.13g\;wet\;wt./m^2$ at bedrock site and $448.85g\;wet\;wt./m^2$ at boulder site. Ecklonia cava was the most dominant species, occupying 62.64% ($1,002.93g/m^2$)of total biomass at bedrock. Amphiroa anceps was the most dominant species and subdominant species was Ecklonia cava, Grateloupia angusta, Peyssonnelia capensis and Meristotheca papulosa at boulder site. Density and biomass of macrobenthos were estimated to be $106.9indivi./m^2$ and $871.93g/m^2$, respectively at bedrock site and they were $64.6indivi./m^2$ and $984.28g/m^2$ at boulder site. The dominant macrobenthos species based on biomass were Turbo comutus (36.40%), Astralium haematragum (19.18%) and Anthocidaria crassispina (13.61%) at bedrock site and they were Alveopora japonica (54.13%) and Psammocora profundacella (24.28%) at boulder site.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.417-422
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• 2015

This paper introduces the design and operational considerations for TBM tunneling in boulder bed which poses significant problems in terms of advance rate and machine wear. Managing these problems is difficult since normal soil investigation techniques do not accurately predict the presence and frequency of boulders. This has leads to considerable extra costs and delays during construction. In this paper, EPBM design and operational parameters, cutter wear characteristics and soil conditioning method in soft ground condition were studied and key successes were highlighted for future projects in similar ground condition.

• The Journal of the Petrological Society of Korea
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• v.25 no.1
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• pp.29-37
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• 2016

A "granite boulder", ~70 cm in size, was reported from the Geumgang Limestone, and has been considered as a glaciogenic dropstone. Since this interpretation has enormous implications for unraveling the evolution history of the Ogcheon Metamorphic Belt, we re-examined the contact relationship and structure of the "granite boulder", and estimated its emplacement age based upon SHRIMP U-Pb zircon dating. The weighted mean $^{206}Pb/^{238}U$ age pooled from 6 spot analyses of two specimens is $170{\pm}2Ma$ ($2{\sigma}$, MSWD=2.2). This zircon age suggests that the "granite boulder" in the Geumgang Limestone is a part of Jurassic granite, rather than a glaciogenic dropstone.