岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2014年
2期
573-583
,共11页
基坑%支护体系%冗余度%连接节点%离散元
基坑%支護體繫%冗餘度%連接節點%離散元
기갱%지호체계%용여도%련접절점%리산원
excavation%retaining structure%redundancy%connection node%discrete elements
目前基于构件设计的基坑设计理论使得很多支护体系缺乏必要的冗余度，并导致了众多基坑事故。将离散元方法引入到基坑垮塌模拟和冗余度研究中，提出了基于局部破坏的冗余度分析模拟方法。进而以探究支撑端部连接对支护结构冗余度的影响为例，对两种连接情况的基坑的破坏过程进行了模拟，对其中的连续破坏现象进行了分析，并将模拟结果与实际工程进行了对比。结果表明，支护体系冗余度的提高可以有效地抵抗连续破坏的发生，防止基坑在局部损伤情况下，由一种形式的破坏引发其他形式的破坏，由局部破坏导致整体崩溃。另外，模拟结果也验证了离散元法在基坑破坏模拟中的适用性与可行性，为类似地下工程的破坏模拟和基坑冗余度的深入研究提供了参考。
目前基于構件設計的基坑設計理論使得很多支護體繫缺乏必要的冗餘度，併導緻瞭衆多基坑事故。將離散元方法引入到基坑垮塌模擬和冗餘度研究中，提齣瞭基于跼部破壞的冗餘度分析模擬方法。進而以探究支撐耑部連接對支護結構冗餘度的影響為例，對兩種連接情況的基坑的破壞過程進行瞭模擬，對其中的連續破壞現象進行瞭分析，併將模擬結果與實際工程進行瞭對比。結果錶明，支護體繫冗餘度的提高可以有效地牴抗連續破壞的髮生，防止基坑在跼部損傷情況下，由一種形式的破壞引髮其他形式的破壞，由跼部破壞導緻整體崩潰。另外，模擬結果也驗證瞭離散元法在基坑破壞模擬中的適用性與可行性，為類似地下工程的破壞模擬和基坑冗餘度的深入研究提供瞭參攷。
목전기우구건설계적기갱설계이론사득흔다지호체계결핍필요적용여도，병도치료음다기갱사고。장리산원방법인입도기갱과탑모의화용여도연구중，제출료기우국부파배적용여도분석모의방법。진이이탐구지탱단부련접대지호결구용여도적영향위례，대량충련접정황적기갱적파배과정진행료모의，대기중적련속파배현상진행료분석，병장모의결과여실제공정진행료대비。결과표명，지호체계용여도적제고가이유효지저항련속파배적발생，방지기갱재국부손상정황하，유일충형식적파배인발기타형식적파배，유국부파배도치정체붕궤。령외，모의결과야험증료리산원법재기갱파배모의중적괄용성여가행성，위유사지하공정적파배모의화기갱용여도적심입연구제공료삼고。
The conventional design method of deep excavation retaining structure generally processes element by element, consequently, some retaining structures are probably lack of essential redundancy, which is one of the reasons that led to many catastrophic collapses of deep excavations. Discrete element method (DEM) is adopted for simulation of excavation collapse and study of retaining structure redundancy;and a simulation method based on local failure for analyzing redundancy is also proposed. Here the influence of prop connection on the retaining structure redundancy is selected as an example of redundancy research. The failure processes of two excavations with different types of prop connections are simulated; and the phenomena of progressive collapses in them are compared and analyzed. Furthermore, the simulation results are also validated by comparison with the realistic case of excavation collapse. It is indicated that the improvement of the retaining structure redundancy can effectively resist the progressive collapse in deep excavation, and then the transformation of a type of damage to other types of damages and the evolution of the local damage to entire collapse can be avoided. In addition, the simulation results also show that the excavation collapse using DEM is feasible and reasonable, so as to provide a reference for simulation of such collapse problems in underground engineering and further study of redundancy in deep excavations.
