個別元素法於潛盾開挖引致礫石層沉陷特性之應用研究

Using bonded-particle model simulating gravel-deposit settlement induced by shield tunneling

詹尚書(Shang-Shu Zhang)

指導教授 ： 王泰典

國立臺北科技大學/工程學院/資源工程研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00378

摘要

台灣土地資源取得不易，都會區之交通網往往建置於地下空間中，常使用潛盾隧道開挖工法來鑽掘，而地層變形為潛盾開挖最重要之考慮因素。因國內外關於礫石層潛盾開挖案例甚少，且受限於礫石層特殊地質與工程特性—由顆粒與基質組成，其個別力學特性差異甚大，力學行為介於土壤與岩石之間，且受力後具有明顯之剪脹特性，利用彈性等向性模式描述不易，且欲應用連體模式發展之數值方法加以預測礫石層潛盾開挖變形特性，需要大量試驗以獲現地參數，耗時費力。
本研究以顆粒力學理論為基礎，應用顆粒流數值軟體PFC2D建構大地模型，並以現地直剪試驗結果為數值模擬獲取微觀參數之準則，並搭配一微觀參數轉換試驗，以弭平顆粒力學理論之尺寸效應影響，最終用獲得之微觀參數模擬現地開挖歷程，並與實際隧道開挖監測資料比對後，探討潛盾開挖引致礫石層之沉陷特性，並進一步模擬潛盾輔助工法—灌漿工法對地盤沉陷之成效。
研究結果顯示利用顆粒力學數值模擬技術，能有效模擬礫石層特殊地質、工程特性，並適合應用於模擬礫石層潛盾開挖之行為探討與灌漿工法之研究。

關鍵字

顆粒力學 ； 礫石層 ； 潛盾開挖 ； 沉陷曲線 ； 灌漿改良

並列摘要

As the special terrain of Taiwan environmental, land for living and activities more focused on Taiwan's western plains and alluvial valleys, the result difficult to obtain valuable land resources, transportation network in urban areas tend to build on the ground floor space, common excavation construction method shall shield construction method. To guard against the effects of ground subsidence caused by excavation to the surface of buildings, often using the construction of the auxiliary shield law to prevent excessive settlement, and special areas to prevent the settlement, then use the grouting method to curb settlement site. However, improving the effectiveness of the current study of more than filling the continuum hypothesis using numerical software, by changing the mechanical properties of the soil around the tunnel parameters to simulate, can’t effectively change the method of grouting soil porosity, bonding paste and the soil and increase soil effective stress.
In this study, non-continuum theories assume that individual element to explore the gravel layer at different scales the mechanical properties of macroeconomic parameters and patterns of behavior and to understand the behavior of the auxiliary methods. First build direct shear test model to compare with the present to get in as the scale, the same mechanical parameters of the microscopic parameters, and then build a larger scale this microscopic parameters of single pressure test in order to consider the impact of scale effects, and compare to obtain the same behavior, and finally to the same behavior of microscopic parameters of the shield as a parameter set based on the excavation, in order to facilitate follow-up to improve the effectiveness of grouting and simulation study.
The results show that the use of individual elements of simulation shield excavation caused subsidence curve and improve the effectiveness of grouting the results are excellent, and the obtained numerical simulation of gravel behavior microscopic parameters are available to follow up the basis for industry and academic research.

並列關鍵字

Granular Mechanics ； Gravel Deposits Layer ； Shield Excavation ； Settlement Curve

參考文獻

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