• 국제학술발표논문집
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• The 7th International Conference on Construction Engineering and Project Management Summit Forum on Sustainable Construction and Management
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• pp.242-244
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• 2017

Excavation for construction is implemented in natural geographical terrain using a variety of construction equipment. Therefore, 3D excavation simulation requires integration of geographical and equipment modeling. This paper proposes a technique that integrates geographical and equipment modeling for 3D simulations of construction excavation. The geographical model uses a digital map to show ground surface changes during excavation and the equipment model shows equipment movement and placement. This combination produced a state of the art 3D simulation environment that can be used for machine guidance. An equipment operator can use the 3D excavation simulation to help construction equipment operators with decisions during excavation work and consequently improve productivity.

• Geomechanics and Engineering
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• 제16권4호
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• pp.399-413
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• 2018

This paper addresses the issue of field measurement of excavation damage zone (EDZ) and its numerical simulation method considering both excavation unloading and blasting load effects. Firstly, a 2000 m-deep rock cavern in China is focused. A detailed analysis is conducted on the field measurement data regarding the mechanical response of rock masses subjected to excavation and blasting operation. The extent of EDZ is revealed 3.6 m-4.0 m, accounting for 28.6% of the cavern span, so it is significantly larger than rock caverns at conventional overburden depth. The rock mass mechanical response subjected to excavation and blasting is time-independent. Afterwards, based on findings of the field measurement data, a numerical evaluation method for EDZ determination considering both excavation unloading and blasting load effects is presented. The basic idea and general procedures are illustrated. It features a calibration operation of damage constant, which is defined in an elasto-plastic damage constitutive model, and a regression process of blasting load using field blasting vibration monitoring data. The numerical simulation results are basically consistent with the field measurement results. Further, some issues regarding the blasting loads, applicability of proposed numerical method, and some other factors are discussed. In conclusion, the field measurement data collected from the 2000 m-deep rock cavern and the corresponding findings will broaden the understanding of tunnel behavior subjected to excavation and blasting at great depth. Meanwhile, the presented numerical simulation method for EDZ determination considering both excavation unloading and blasting load effects can be used to evaluate rock caverns with similar characteristics.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.395-406
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• 2008

An excavation with the depth of 32.7m will be constructed as a ventilation shaft in Shanghai metro Line 9. The excavation induced effect on a nearby undercrossing road in operation must be properly evaluated. A centrifuge model test was conducted to study the impact of deep excavation on this existing undercrossing. Detail simulation works are described in this paper. The excavation steps could be simulated in the no-stop state of centrifuge machine. And induced settlements of the undercrossing road in both parallel and vertical directions were analyzed. Protective partition cement soil piles were also simulated in the tests. Simulation test shows deep excavation has a great influence on undercrossing road and the partition pile can obviously deduce the influence.

• Geomechanics and Engineering
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• 제30권2호
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• pp.153-167
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• 2022

This study proposes a method to analyze the distribution of coal porosity disturbances after the excavation of ultra-large-diameter water jet boreholes using a coal wetting and softening model. The high-pressure jet is regarded as a short-term high-pressure water injection process. The water injection range is the coal softening range. The time when the reference point of the borehole wall is shocked by the high-pressure water column is equivalent to the time of high-pressure water injection of the coal wall. The influence of roadway excavation with support and borehole diameter on the ultra-large-diameter jet drilling excavation is also studied. The coal core around the borehole is used to measure the gas permeability for determining the porosity disturbance distribution of the coal in the sampling plane to verify the correctness of the simulation results. Results show that the excavation borehole is beneficial to the expansion of the roadway excavation disturbance, and the expansion distance of the roadway excavation disturbance has a quadratic relationship with the borehole diameter. Wetting and softening of the coal around the borehole wall will promote the uniform distribution of the overall porosity disturbance and reduce the amplitude of disturbance fluctuations.

• 터널과지하공간
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• 제6권4호
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• pp.326-334
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• 1996

In underground construction the multi-step excavation sequence is commonly adopted for the convenience of the underground work. A numerical simulation method which is capable of analyzing the effects of excavation sequence on the stability of the opening is greatly needed. In this study a two dimensional finite element code was developed based on the effective numerical algorithm for the multistep excavation. The practical applicability of the model was verified for the simplified excavation sequences.

• 한국터널지하공간학회 논문집
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• 제21권6호
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• pp.849-860
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• 2019

본 논문은 쉴드 TBM의 급곡구간 굴착 시 안정성에 대한 데이터를 얻기 위한 장비 시스템 개발 연구이다. 최근 터널 굴착에 쉴드 TBM 장비가 많이 활용되고 있다. 굴착 시 지반 상부의 건물이나 기존 지하 구조물에 의해 불가피 하게 우회해야 할 경우가 발생할 수 있다. 이러한 경우에 대비하여 시공의 안정성을 확인하기 위해 시공 전 사전 시뮬레이션이 필요로 한다. 그러므로 본 장비 시스템 개발로 자동화 제어시스템을 구축하여 급곡구간 굴착 모형 시뮬레이션을 통해 모의실험을 진행한다면 안정성을 높일 수 있을 것이다. 장비의 좌·우 각도 및 추력 등을 제어하며 굴착 시 장비에 받는 토압, 추진압에 대한 데이터를 실시간으로 볼 수 있도록 시스템을 개발하여야 한다. 이 시스템으로 굴착 방법과 각도 별 굴착 시뮬레이션을 통한 현장실험에 필요데이터를 수집할 수 있다. 실제 쉴드 TBM 공사 전 축소모형 실험을 통한 평가 시 매우 유용하게 활용될 수 있을 것으로 기대된다.

• 한국터널지하공간학회 논문집
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• 제4권3호
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• pp.185-193
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• 2002

본 연구에서는 풍화토층에 굴착된 지하철 터널의 변형거동과 종방향 지보재의 보강효과가 3차원 유한차분해석에 의해 조사되었다. 굴착방법이 터널 변형거동에 미치는 영향을 조사하기 위해서 반단면 및 전단면의 2가지 굴착방법이 고려되었다. 또한, 우산형 막장보강법 (RPUM) 및 유리섬유 파이프의 보강효과가 비교되었다. 터널 변형거동을 분석하기 위해 막장변위, 내공변위, 선행변위 및 측벽변위가 조사되었고, 굴착방법 및 종방향 지보재의 효과가 지표침하량를 사용하여 분석되었다. 해석 결과, 반단면 굴착이 전단면 굴착 보다 더 큰 내공변위, 선행변위, 측벽변위를 야기시키며, 반면 막장변위는 전단면 굴착이 반단면 굴착에 비해 더 크게 발생됨을 알았다. 또한, 같은 굴착방법에서는 RPUM만이 사용되었을 때가 RPUM이 유리섬유 파이프와 같이 사용되었을 때 보다 모든 변위가 더 켜졌다.

• 대한기계학회논문집A
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• 제32권11호
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• pp.984-989
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• 2008

Hydraulic excavators have been one of the most popular devices in the various industries for construction, forestry and agriculture etc. Because the excavators generally work in poor environment, the various organizations study to automate those. In this paper, a hydraulic simulation for evaluation of automatical excavation system is presented. It is using the AMESim based on the 1.5 ton excavator with fixed displacement pumps, and operated by signals those control pilot pressure to spools of the main control valve. The main control valve is regarded that only consists of boom, arm and bucket. This simulation program is expected to apply to evaluation of the controller for automatic excavation system and to estimate of effect in accordance with change of some components or parameter.

• Structural Engineering and Mechanics
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• 제84권6호
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• pp.743-765
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• 2022

Near-surface excavations may cause the tilting and destruction of the adjacent superstructures in big cities. The stability of a huge excavation and its nearby superstructures was studied in this paper. Some test instruments monitored the deformation and loads at the designed location. Then the numerical models of the excavation were made in FLAC3D (a three-dimensional finite difference code) and Plaxis-3D (a three-dimensional finite element code). The effects of different supporting and reinforcement tools such as nails, piles, and shotcretes on the stability and bearing capacity of the foundation were analyzed through different numerical models. The numerically approximated results were compared with the corresponding in-field monitored results and reasonable compatibility was obtained. It was concluded that the displacement in excavation and the settlement of the nearby superstructure increases gradually as the depth of excavation rises. The effects of support and reinforcements were also observed and modeled in this study. The settlement of the structure gradually decreased as the supports were installed. These analyses showed that the pile significantly increased the bearing capacity and decreased the settlement of the superstructure. As a whole, the monitoring and numerical simulation results were in good consistency with one another in this practically important project.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1992년도 가을 학술발표회 논문집
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• pp.174-179
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• 1992

In this paper a discussion is presented about excavation responses of underground openings for radioactive waste disposal. The effects of excavation methods, stress redistribution, thermal change, and backfill materials are reviewed. Comparisons of computational models for discontinuous reek masses and discussions on numerical simulation techniques for the excavation of underground openings are also described. Finally, the application of the CAD system to the planning, design and construction of underground openings fop radioactive waste disposal is introduced.