황철석으로 조성된 성토구조체의 중화제 주입을 위한 최적 방안 제안

송영석,윤중만 한국지반신소재학회 2023 한국지반신소재학회 논문집 Vol.22 No.4

본 연구에서는 황철석 암버럭으로 시공된 성토체를 대상으로 산성배수 발생을 억제하기 위하여 중화제를 주입할 경우 최적의주입방안을 제시하고자 한다. 성토체 내에 중화제 주입으로 인한 침투효과를 수치해석으로 검토하기 위하여 유한요소해석을수행하였다. 수치해석을 위하여 중화제 주입관의 직경을 50mm로 선정하고 주입관의 간격을 1-4m, 주입압을 100-220kPa로변화시키면서 침투해석을 수행하였다. 해석결과에 따르면 중화제의 주입관 간격 1.0m 및 주입압 130kPa인 경우와 주입관간격 2.0m 및 주입압 160kPa인 경우가 상대적으로 낮은 주입압에서 성토체 전체의 포화 도달시간이 빠른 것으로 나타났다. 그리고, 성토체 전체의 포화를 위한 중화제 주입관의 간격은 3m인 경우 130kPa에서 190kPa까지 다양한 주입압을 적용할수 있으며, 성토체의 포화 도달시간은 주입압에 상관없이 유사한 것으로 나타났다. 따라서 경제성을 고려한 최적의 중화제주입조건으로 주입관의 간격은 3.0m, 주입압은 130kPa로 선정하였다. In this study, the optimal method for injection of neutralizer to restraint the leakage of acid drainage in embankment structure composed of pyrite rocks is proposed. Finite Element Analysis was performed to examine the seepage effect caused by injection of neutralizer into the embankment structure. The diameter of the neutralizer injection hole was selected as 50cm, the interval space of injection ranged from 1m to 4m and the injecting pressure ranged from 100kPa to 220 kPa were applied for the numerical analysis. According to the analysis results, the saturation time of the whole embankment structure was shown to be fast at a relatively low injecting pressure in the case of injecting interval space of 1.0m and injecting pressure of 130kPa and in the case of injecting interval space of 2.0m and injecting pressure of 160kPa. When the interval space of injection for saturation of whole embankment structure is selected as 3m, various injection pressures can be applied from 130kPa to 190kPa, and the saturation time of whole embankment is similar regardless of the injection pressure. Therefore, the optimal method for injection of neutralizer considering economic efficiency was selected as injecting interval space of 3.0m and injection pressure of 130kPa.

Settlement behavior and controlling effectiveness of two types of rigid pile structure embankments in high-speed railways

Wang, Changdan,Zhou, Shunhua,Wang, Binglong,Guo, Peijun,Su, Hui Techno-Press 2016 Geomechanics & engineering Vol.11 No.6

In this study, a series of geotechnical centrifugal tests were conducted to investigate the effectiveness of settlement control of two types of rigid pile structure embankments (PRSE) in collapsible loess under high-speed railway embankments. The research results show that ground reinforcement is required to reduce the post-construction settlement and settlement rate of the embankments. The rigid pile structure embankments using rigid piles can substantially reduce the embankment settlement in the construction of embankments on collapsible loess, and the efficiency in settlement reduction is affected by the pile spacing. The pile-raft structure embankments (PRSE) have much stronger ability in terms of the effectiveness of settlement control, while the pile-geogrid structure embankments (PGSE) provides rapid construction as well as economic benefits. Rational range of pile spacing of PRSE and PGSE are suggested based on the requirements of various railways design speeds. Furthermore, the time effectiveness of negative skin friction of piles and the action of pile-cap setting are also investigated. The relevant measures for improving the bearing capacity and two parts of transition zone forms as positive control mean have been suggested.

Numerical modelling of a pile-supported embankment using variable inertia piles

Daniel Dias,Jérôme Grippon 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.61 No.2

The increasing lack of good quality soils allowing the development of roadway, motorway, or railway networks, as well as large scale industrial facilities, necessitates the use of reinforcement techniques. Their aim is the improvement of the global performance of compressible soils, both in terms of settlement reduction and increase of the load bearing capacity. Among the various available techniques, the improvement of soils by incorporating vertical stiff piles appears to be a particularly appropriate solution, since it is easy to implement and does not require any substitution of significant soft soil volumes. The technique consists in driving a group of regularly spaced piles through a soft soil layer down to an underlying competent substratum. The surface load being thus transferred to this substratum by means of those reinforcing piles, which illustrates the case of a piled embankment. The differential settlements at the base of the embankment between the soft soil and the stiff piles lead to an “arching effect” in the embankment due to shearing mechanisms. This effect, which can be accentuated by the use of large pile caps, allows partial load transfer onto the pile, as well as surface settlement reduction, thus ensuring that the surface structure works properly. A technique for producing rigid piles has been developed to achieve in a single operation a rigid circular pile associated with a cone shaped head reversed on the place of a rigid circular pile. This technique has been used with success in a pile-supported road near Bourgoin-Jallieu (France). In this article, a numerical study based on this real case is proposed to highlight the functioning mode of this new technique in the case of industrial slabs.

한국 고대 성토구조물에서 토괴의 기능과 의미

손재현 중앙문화재연구원 2015 중앙고고연구 Vol.0 No.17

한국 고대 성토구조물로는 고분·토성·제방·대형 건물 등이 있다. 최근 이들 유적의 발굴조 사 과정에서 덩어리 형태의 흙, 즉 토괴를 성토재로 사용한 경우가 다수 확인되고 있어 주목된다. 토괴는 그간 다양한 용어로 명명되었으며 주로 구획과 밀접한 관련을 지니는 것으로 인식되어 왔다. 하지만 용어의 혼용으로 토괴의 명확한 개념 정리가 이루어지지 못했고, 토괴의 사용 양상 에 대한 관행적 해석이 반복됨에 따라 토괴 사용이 갖는 기능과 의미에 대해서 구체적으로 밝혀 지지 못했다. 본고에서는 먼저 토괴의 개념정리 후 토괴 사용이 알려진 유적 27개소를 대상으로 삼아 검토 하였다. 그 결과 고분·성곽·제방·대형 건물 등 성토구조물이라 볼 수 있는 모든 유구의 축조 에서 토괴의 사용이 확인되었다. 다음으로 현대공법과 유적 검토 결과를 참고하여 토괴의 구분 기준을 제시하고, 분류를 시도하 였으며, 사용방법과 기능을 제시하였다. 토괴의 사용방법은 유적의 성격에 따라 차이가 있음을 확인할 수 있었다. 유구의 성격뿐 아니 라 사용된 토괴의 종류 또한 채토환경의 영향을 받고 종류에 따른 다양한 기능을 얻고자 선택적 으로 사용되었음을 알 수 있었다. 한편 해외 유적 사례 검토를 통해 중국, 일본, 넓게는 서~중앙아시아에서도 토괴가 사용되었 음을 확인하게 되면서 토괴를 사용한 축조기술은 특정지역을 대표하는 것이 아니라 오랜 기간 광 범위한 지역에서 사용되었음을 파악할 수 있었다. 이렇듯 기후조건이 달랐음에도 토괴가 널리 쓰 인 이유는 토괴가 갖는 다양한 기능을 얻기 때문이었을 것이다. 이러한 근거를 통해 성토구조물의 축조에서 토괴의 사용이 갖는 의미를 단순한 운반의 편의성 으로만 볼 것이 아니라 주요 성토기법을 보조하는 하나의 보조공법으로 이해되어야 할 것으로 판 단된다. Korea’s ancient Embankment structures are assemblages a complex of advanced technologies, that is results of reflected in national power. Embankment structures include burial mounds, earthen fortications, embankments and large buildings. In recent excavations involving these structures, there are many cases that have been discovered to have used lump shaped soil, as known as clay clod, and such cases are drawing attention. Clay clods have been named in many different terms and have been thought to have close relationship with dividing sections. But with the mixed use of different terms, clarification of the concept of clay clod was not made and as conventional interpretations on the aspects of usage of clay clods were made continuously, the function and the meaning that the use of soil clods holds were not specifically identied. This paper firstly clarifies the concept of clay clod and examines 27 sites that have been known to have used clay clods. As a result of examination, it was revealed that every features that can be identied as mound structures such as burial mounds · fortications · embankments · large buildings and etc have used clay clods. Nextly, by referring to modern building techniques and the result of examination of sites, this paper renders a criteria to classify soil clods, classifies the soil clods and renders the methods of use and meanings of soil clods. It was found out that the usage of clay clods differs by the character of a site. The type of clay clod that is used is influenced not only by the character of the feature, but also by the condition of the soil collecting, and it was found out that the each types were collectively used to obtain diverse functions. Meanwhile, by examining sites overseas, the paper found out that soil clods were used in China, Japan and also in West~Central Asia and reveals that mounding technique involving the use of soil clods is not something that is limited to a specic region but a widespread technique in many different regions used over time. clay clodwould have been broadly used, despite the climate dierence, in order to obtain dierent functions from it. In this reason, the meaning of the usage of clay clods in the construction of Embankment structures should be understood not just as simplifying the transport of soil, but as an auxiliary construction technique that assists the main mounding technique.

Optimal monitoring instruments selection using innovative decision support system framework

Isa Masoumi,Kaveh Ahangari,Ali Noorzad 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.21 No.1

Structural monitoring is the most important part of the construction and operation of the embankment dams. Appropriate instruments selection for dams is vital, as inappropriate selection causes irreparable loss in critical condition. Due to the lack of a systematic approach to determine adequate instruments, a framework based on three comparable Multi-Attribute Decision Making (MADM) methods, which are VIKOR, technique of order preference by similarity to ideal solution (TOPSIS) and Preference ranking organization method for enrichment evaluation (PROMETHEE), has been developed. MADM techniques have been widely used for optimizing priorities and determination of the most suitable alternatives. However, the results of the different methods of MADM have indicated inconsistency in ranking alternatives due to closeness of judgements from decision makers. In this study, 9 criteria and 42 geotechnical instruments have been applied. A new method has been developed to determine the decision makers\' importance weights and an aggregation method has been introduced to optimally select the most suitable instruments. Consequently, the outcomes of the aggregation ranking correlate about 94% with TOPSIS and VIKOR, and 83% with PROMETHEE methods' results providing remarkably appropriate prioritisation of instruments for embankment dams.

Optimal monitoring instruments selection using innovative decision support system framework

Masoumi, Isa,Ahangari, Kaveh,Noorzad, Ali Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.21 No.1

Structural monitoring is the most important part of the construction and operation of the embankment dams. Appropriate instruments selection for dams is vital, as inappropriate selection causes irreparable loss in critical condition. Due to the lack of a systematic approach to determine adequate instruments, a framework based on three comparable Multi-Attribute Decision Making (MADM) methods, which are VIKOR, technique of order preference by similarity to ideal solution (TOPSIS) and Preference ranking organization method for enrichment evaluation (PROMETHEE), has been developed. MADM techniques have been widely used for optimizing priorities and determination of the most suitable alternatives. However, the results of the different methods of MADM have indicated inconsistency in ranking alternatives due to closeness of judgements from decision makers. In this study, 9 criteria and 42 geotechnical instruments have been applied. A new method has been developed to determine the decision makers' importance weights and an aggregation method has been introduced to optimally select the most suitable instruments. Consequently, the outcomes of the aggregation ranking correlate about 94% with TOPSIS and VIKOR, and 83% with PROMETHEE methods' results providing remarkably appropriate prioritisation of instruments for embankment dams.

청계만 식물플랑크톤 크기구조의 계절적 변동

지성,신용식,서호영,Ji, Sung,Sin, Yong-Sik,Soh, Ho-Young 한국해양학회 2008 바다 Vol.13 No.4

청계만에는 3개의 방조제(창포, 복길, 구일)가 위치하고 있고 이로부터 유입되는 담수로 인한 환경의 변화가 예상된다. 이를 조사하기 위해 2006년 11월(가을), 2007년 2월(겨울), 5월(봄), 8월(여름)에 각 방조제 앞에서 3개 정점을 선정하였다. 각 방조제 정점에서 대발생은 갈수기인 2007년 2월에 대형식물플랑크톤에 의해 발생하였고 풍수기에는 중 형식물플랑크톤이 우점하는 분포를 나타냈다. 각 방조제 정점에서 풍수기에는 담수의 유입으로 인하여 염분과 투명도는 낮고 암모늄과 인산염은 갈수기인 2007년 2월보다 높게 나타났지만 식물플랑크톤 생체량은 낮게 나타났는데 이는 담수의 유입으로 인한 높은 탁도나 염분의 급격한 감소가 영양염류보다 더 영향을 미치는 것으로 사료된다. 즉 본 조사해역에서 갈수기인 2007년 2월에는 식물플랑크톤의 성장에 영양염류가 영향을 미치지만 풍수기에는 높은 탁도나 급격한 염분변화가 영양염류보다 더 큰 영향을 미치는 것으로 판단된다. Three embankments are located in the Chunggye Bay, each named as Changpo, Bokkil and Kuil and environmental changes are expected due to freshwater input. To investigate this phenomenon, three sample sites in front of each embankment gate were selected in Nov. 2006(autumn), Feb. 2007(winter), May. 2007(spring) and Aug. 2007(summer). At every point of embankment spot, large cells(micro-size, >$20\;{\mu}m$) of phytoplankton were turned out to be a major cause of algal bloom in Feb. 2007 and nano-size($2-20\;{\mu}m$) phytoplankton became dominant during rainy season. In rainy season, each point of embankment showed low salinity and transparency with higher ammonium and phosphorus concentrations than dry season. However, the number of phytoplankton has decreased and it is expected that freshwater influx has more influence on high turbidity and radical decrease of salinity than nutrient. According to the results of this study, therefore, nutrient could have more influence on growth of phytoplankton in dry season, but high turbidity and radical changes of salinity have more influence in rainy season.

Application of a modified structural clay model considering anisotropy to embankment behavior

Zhang, Hao,Chen, Qiushi,Chen, Jinjian,Wang, Jianhua Techno-Press 2017 Geomechanics & engineering Vol.13 No.1

Natural clays exhibit features such as structural and anisotropy. In this work, a constitutive model that is able to replicate these two salient features of natural clays is presented. The proposed model is based on the classical S-CLAY1 model, where the anisotropy of the soil is captured through the initial inclination and rotation of the yield surface. To account for the structural of the soil, the compression curve of the reconstituted soil is taken as the reference. All parameters of the proposed constitutive model have clear physical meanings and can be conveniently determined from conventional triaxial tests. This proposed model has been used to simulate the behavior of soft soil in the undrained triaxial tests and the performance of Murro embankment in terms of settlement and horizontal displacements during embankment construction and consolidation stage. Results of numerical simulations using proposed model have been compared with the field measurement data. The comparisons show that the two features significantly influence the prediction results.

작업 연쇄를 활용한 한국 고대 제방 축조 공정의 복원

조미래(Jo, Mirae) 한국고고학회 2022 한국고고학보 Vol.- No.122

본고에서는 한국 고대 제방을 연구 대상으로 삼아 당대의 축조 기술 사용 양상을 분석했다. 자료를 해석하기 위한 틀로 작업 연쇄(Cha^ne O`peratoire )를 채택하였는데, 작업 연쇄는 물질자료의 생성 과정에서 수반되는 모든 기술적 선택들을 재조직하는 방법론이다. 분석 과정에서는 ‘작업 공정의 세분화’와 ‘끊임없는 선택과 의사결정’에 주목하여, 제방의 순차적 축조 공정을 복원하고 그 과정에서 사용된 기법들을 추출함으로써 특정 기법의 선택에 영향을 준 다양한 요인을 분석하고자 했다. 제방 축조의 작업 연쇄 복원을 시도하는 과정에서 한국 고대 제방 축조에 사용된 기술의 종류는 제한적이었거나 유사했던 반면 그러한 기술이 구현되는 방식은 축조 집단에 따라 다양하게 나타났음을 확인할 수 있었다. 또한 이러한 기술적 선택과 관련된 기술의 기능 및 사용 목적에 대한 인식, 상황에 따른 기술의 선택과 응용 방식, 환경에 따른 자원의 이용 가능성에 대한 인식, 이전 공정에서의 선택이 다음 공정에서의 기술 선택에 미친 영향 등을 확인할 수 있었다. This paper explores the use of the building technologies of seven excavated embankments from the Ancient Period of Korea. This research applies Chaîne Opératoire to understand and organize the embankments data. The concept of ‘fragmentation of the operation’ and ‘decision making for the choice’ helps to reproduce the building process and identify the building techniques, thereby approaching the analysis on various factors that bring about a choice among alternatives. The operational sequence of the embankments shows that while the types of building techniques were limited, the way in which the techniques were used varied according to each embankment site. With regard to technological choices, there were the knowledge for technical function and purpose, the identification of the surrounding environment which could limit or widen the variety of choices, the fact that the former technological choice structured the latter choice, and so on.

아라가야 토목구조물의 기술적 특징과 그 의미

최경규 ( Choi Gyong-gyu ) 동아문화재단 2019 文物硏究 Vol.- No.36

고대국가 단계에 지배 엘리트의 무덤인 고총고분, 행정센터인 도성, 방어중심인 산성, 종교적 기념물인 신전과 사원, 재해로부터의 방어와 농경의 필수요소인 제방의 건축에는 당시 사회정치적 발전과 권력의 중앙 집중화 정도를 내포하고 있다. 이러한 토목구조물의 조사 자료가 비교적 잘 확보된 아라가야를 대상으로, 축조 기술적 특징과 토목구조물에서 보이는 상호연관성을 살펴보고, 아라가야에서 토목구조물이 가지는 의미에 대해 검토해 보았다. 그 결과, 당시 최고의 토목공법이 사용된 거대 토목구조물인 말이산 고총고분, 가야리유적(전 아라가야 왕궁지), 안곡산성, 가야리제방의 축조에는 상호 공통된 토목공법이 확인되고 있는것을 확인하였다. 국가적 사업인 대규모 토목공사에 나타난 이러한 양상을 통해 동원된 기술자집단 또는 관리집단이 동일하였을 가능성을 상정해 볼 수 있었다. 그리고 백제 한성기 토성의 특징적인 토목공법인 토제가 말이산 고총고분에 상당히 적극적으로 활용된 양상을 통해 주변 선진토목기술의 적극적 도입을 위한 활발한 기술교류도 추정해 볼 수 있었다. 이러한 국가적 토목구조물을 축조하는 데에는 인구증가에 의한 노동력의 확보, 선진 토목기술의 축적 등이 필요하며 이를 운영ㆍ관리할 수 있는 체제의 안정이 필수적이다. 아라가야에서는 상기의 토목구조물이 5세기 후반 거의 동시기에 일률적으로 중심지에 배치되는데, 이때가 가장 강력한 국가적 역량을 보이는 시기로 생각된다. In the ancient state stage, the tombs of the ruling elite, the capital city, the fortress, the defensive center, the mountain fortress, the religious monument, a shrine and the temple, and the construction of the embankment, which are essential elements of agriculture, implies the degree of social and political development and centralization of power. For Ara-Gaya, where the survey data of these civil structures are relatively well secured, the construction technical features and interrelationships shown in the civil structure were reviewed and the implications of the civil structure were reviewed in Ara-Gaya. As a result, it was confirmed that common civil engineering methods were found in the construction of the Mari-san Tomb, the Gaya ruins (formerly Ara-gaya Palace), Angoksanseong Fortress, and Gayari Embankment, a large civil engineering structure where the best civil engineering methods were used at that time. This aspect of the large-scale civil engineering work, which is a national project, could be assumed to have been the same for the mobilized technical or management groups. In addition, it was possible to estimate active technological exchanges for the active introduction of advanced civil engineering technologies in the Baekje Dynasty through the highly active use of the characteristic civil engineering method of earrthen a bank, which was made during the Hanseong period of The Baekje Dynasty. Building these national civil structures requires securing workforce by population growth, accumulation of advanced civil engineering technologies, etc., and stability of the system to operate and manage them is essential. In Ara-Gaya, the above civil structures are placed uniformly in the central area almost simultaneously in the late 5th century, which is thought to be the most powerful period of national capability.