電滲法運用於地下鑽掘包泥問題之可行性探討

Application of Electro-osmosis to Reduce Interfacial Adhesion Between Clay and Cutter for Accessing Tunnel Mechanical Driving

陸嘉(Chia Lu)

指導教授 ： 陳立憲

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2013年)

https://doi.org/10.6841/NTUT.2013.00155

摘要

國內外機械式掘削開挖之隧道工程案例日增，惟因台灣地質複雜多變，施工常遇黏土包泥，因不利排碴而引致掘削機頭阻滯不前，為影響地下工程之進度、成本要因之一。而包泥如依傳統工法解決，如機械刮刀設置或作泥材注漿改善；均較為耗時且效果不彰。故本研究乃以電滲法於國內首次嘗試解決地下鑽刀包泥問題，先由地下施工與包泥造成之工程影響作外業調查；再依多用於地盤改良之電滲工法之理論、機制，運用於地下機械鑽掘包泥解決方案之可行性探討。
本研究再行設計室內砂箱試驗，並簡化模擬地下鑽掘機包泥條件，以變化不同電極棒材質並施以固定30V之電位差；量測負極附近之含水量變化以評估包泥改善效果，並以抗剪扭力之阻抗大小作為檢核其增潤效應之指標，藉由不同電極棒材質、電滲時間、壓密壓力等變數，進行系列探討其試驗之改良成效。
結果顯示，增潤改良效果在無壓密壓力狀況之電滲試驗下，以抗剪扭力T作為直接證據為檢視刀頭包泥之不排水剪力阻抗，試驗T值於5分鐘即有顯著反應，(抗剪扭力已降低26.4 %)；而於最終60分鐘之電滲過程，抗剪扭力大幅降低T0之56.8 %；另外間接證據則計測刀頭包泥附近含水量，在電滲20分鐘即顯著增加約三成五(即含水量由40 %增至54.13 %)；且於最終60分鐘後，含水量增加約五成(由40 %變為59.75 %)。綜析由剪力阻抗大幅降低、含水量顯著增加之增潤效應可應用於機刀包泥之解決方案。最終本文並作外業調查，實地暸解地下鑽掘機具之構造與其相關電機設備，初步提出結合電滲之設計構想與可行性芻議，俾供未來實際應用之佐參。

關鍵字

潛盾工法管推工法 ； 包泥 ； 電滲法 ； 不排水剪力強度 ； 增潤效應 ； 電蝕機制

並列摘要

This study is first attempts on reduce interfacial adhesion between clay and cutter for accessing tunnel mechanical driving use electro-osmosis. First by field investigation for affected by the engineering of Clay Clogging, then more for ground improvement by the electro-osmotic theory and mechanism, used in interfacial adhesion between clay and cutter for accessing tunnel mechanical driving solutions feasibility. And design laboratory experiments, and to simplify the interfacial adhesion between clay and cutter for accessing tunnel mechanical driving conditions to simulation. From the measurement of the water content near the anode in order to assess the effect of improving the clay clogging, and the impedance of the shear torque to Checklist its as an indicator of lubrication effect, with different voltage, electrode rod material, electro-osmosis time, compaction pressure etc variables, conduct series discussed for improved effectiveness of tests.
The results showed improvement effect of enrichment in the absence of compaction pressure electro- osmosis conditions under test, to shear torque T as direct evidence for the inspection of the undrained shear impedance in clay clogging, T value that is significant response in five minutes (shear torque has been reduced by 26.4 %). And in the final 60 minutes of electro-osmosis process, significantly reducing of shear torque T0 of 56.8 %. Another indirect evidence is measuring water content of near cutter. In the electro- osmosis have a significant increase of about 35 % in 20 minutes (water content from 40 % to 54.13 %). And in the final 60 minutes after the water content increased by about 50 % (from 40 % to 59.75 %).
The results of experiments showed different lubricant improvement by each factor. When using tunnel mechanical driving during construction, our ways of lubricant improvements would be a good reference and verification of advanced methods. Besides, by connecting structural research of underground excavation machine with electric machinery, our result provided idea to future design of excavators and suggestion for improvement, increasing feasibility of facilities combining and application on the scene.

並列關鍵字

Shield tunnel ； Pipe jacking ； Clay Clogging ； Electro-osmosis ； Undrained Shear Strenght ； Lubrication Effect ； Electrical Pitting Mechanism

參考文獻

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