場址變位之跨尺度多時序量測整合技術－以隧道工程為例

Multi-scales and Temporal-stages Integrating Survey Technology for Site Displacement : An example of Tunnel Engineering

賴彥儒(Yen-Ru Lai)

指導教授 ： 黃燦輝

國立臺灣大學/工學院/土木工程學研究所/碩士(2013年)

https://doi.org/10.6342/NTU.2013.02956

摘要

工程監測為瞭解場址變形與評估結構體安全性的必要手段，近年來三維測量儀器與技術的蓬勃發展，處理空間資訊的誤差理論已趨於成熟，實務上除了採用傳統的現地監測儀器，三維測量技術已成為不可或缺的項目，用以掌握監測體的三維變形特性。因此，發展監測整合技術來統合監測資訊為大地工程實務上極為重視的課題。
實務與法統上，工程測量採用的坐標框架，需依循內政部國土測繪中心最新公告的絕對坐標框架(例如現在是TWD97與TWVD2001)。使用三維量測技術監測待測區的位移或變形時，需架構於已知點或參考網，但已知點或參考網於測設時即存在的不確定性，且不同時間可能會產生變動。實務上，測量加密網平差採用視已知點為固定無誤的逐級平差模式，將使加密網的成果品質呈現出一種假象，且強制附合已知點會造成網形張力的問題，越下級的加密網之網形張力就越嚴重(尤瑞哲，1984)；而已知點變動可經由已知點檢測作業排除之。實有必要發展監測整合技術統合監測資訊，提出合適的平差模式與監測作業流程，實現工程體生命全週期的第一步。
大地工程界中關注的監測體不外乎隧道、邊坡、深開挖或斷層活動等，其中隧道為網形幾何結構不佳的特殊測量環境，故本研究以最困難的隧道監測為例，使用尤瑞哲(1996)所提出的動力平差模式，或稱為虛擬觀測平差法，依據常見工程測量與監測作業的方法以及選用坐標系統的特性，畫分為全域尺度(macro-scale)、介觀尺度(meso-scale)以及局部尺度(micro-scale)，提出跨尺度多時序監測整合技術並建立相應的監測作業流程，基於誤差理論進行數值模擬實驗，並透過物理模型實驗驗證監測整合技術的應用性，進行單時序參數精度分析與多時序變形與位移分析。
研究結果顯示：隧道加密控制網的誤差行為由隧道橫斷面方向主控，整體的誤差行為受到跨尺度誤差累積的影響，長隧道加密控制網的絕對點位精度已低於公分等級，且考量不對稱隧道控制點精度的成果與傳統採用逐級平差模式的成果差異甚大。隧道網形設計的成果中建議採用矩形且對角連線的單元網型態。應用真北儀於隧道測量可提升隧道加密控制網的精度。藉由本研究所提出的監測整合技術將監測資訊整合至國家公告的絕對坐標系下，並進行變位分析，無論是數值模擬實驗或物理模型實驗的成果中皆顯示，絕對位移受跨尺度誤差累積的影響，可監測性較低；相對變形則不受跨尺度誤差累積的影響，可監測性較高，可視為應變場的概念。最後，建議工程監測保存多時序各尺度平差完成後的完整協變方矩陣，以確保變形分析的正確性與往後跨尺度平差的資料來源。

關鍵字

跨尺度 ； 多時序 ； 監測整合技術 ； 場址變位分析 ； 隧道監測 ； 誤差理論

並列摘要

Engineering monitoring is an essential way to understand the site deformation characteristic and evaluate the safety of structure. In recent years, the rapid development of instruments and techniques to deal with spatial information error theory has matured. Practically, in addition to adopting traditional site monitoring instrument, three-dimensionally surveying instrument has become indispensable item for realize the characteristics of three-dimensional deformation of monitoring object. Therefore, it has been seen as the extremely important issue for geotechnical engineering which is to develop monitoring and integrating techniques to unify monitoring information.
In practice and under law, the adopting coordinate frame of engineering measurement need to follow National Land Surveying and Mapping Center of the ministry of the Interior bulletin absolute coordinate frame (for example, there are TWD97 and TWVD2001 nowadays). Using three-dimensional surveying techniques to monitor the displacement or deformation of the area need to base on a known point or reference network. However, the uncertainty of known point or reference network existed and the change may occur at different times. The conventional hierarchical adjustment model which the coordinates of existing point are viewed as error free. The quality of result will make network present a kind of illusion, and fixed-known point will cause the problem of the tension of net-shaped which is more subordinate hierarchical network, more serious (R.J. You, 1984);
While the known point change can be excluded operation via detecting operation from known points. There are essential to develop integrated techniques to unify monitoring information and propose appropriate adjustment model and monitoring operational processes as the first step to achieve the whole life-cycle for engineering body.
Geodetic engineering concern about monitoring objects, including tunnels, slopes, deep excavation or fault activity and so forth, of which tunnel is net-shaped geometry for the special measurement environment of poor structure. Taking for the most difficult tunnel monitor in this research for example, using R.J. You (1996) proposed the model of the dynamic adjustment, or called as unified least squares adjustment. According to the common way of engineering measurement and monitoring operation and chose characteristics of the coordinate system, which is used to dividing into a macro-scale, meso-scale and micro-scale, propose Multi-scales and Temporal-stages Integrating survey technology and establish appropriate monitoring processes. Based on using error theory to conduct the experiment of numerical simulation, verify the application of monitoring integration techniques through a physical model and analyze the accuracy of the single timing parameters and the analysis of temporal parameters of deformation and displacement.
The result of research indicate that the error behavior of tunnel control network is mainly dominated by the direction of the tunnel cross section, the overall error behavior is affected by the accumulation of cross-scale error, the precision of absolute point of long tunnel encryption control network has fallen below the centimeter level, and there are considerably difference between considering the accurate result of the control point of asymmetric tunnel and adopting traditionally stepwise adjustment model. Otherwise, the gaining from the net-shaped design recommend uses the cell network type of rectangular and diagonal connection, utilize Gyro station can enhance the precision of tunnel encrypted control network as measuring tunnel. Hence, via proposing a monitoring integration information technology from this research that will be integrated into the absolute coordinate system of national bulletin, and conduct displacement analysis. Both the consequence of numerical simulation experiments or physical model experiments are displayed that the evidence the less monitorability when absolute displacement is affected by the cross-scale error accumulation; relative deformation is not subjected to cross-scale error accumulation and can be monitored higher with regarding the conception of strain field. Finally, in order to ensure the correctness and subsequent deformation analysis cross-scale adjustment data sources, I suggest that engineering monitoring must conserve complete full-scale covariance matrix after the accomplishment of each scale and temporal adjustment.

並列關鍵字

multi-scale ； temporal ； integrating survey technology ； tunnel engineering ； error theory

參考文獻

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