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第66期 |
工程案例探討(二) |
可選購電子書 |
謝百鍾 |
1998/04/01 |
90 |
無庫存
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| CASE STUDY OF TBM CONSTRUCTION TECHNIQUES IN SEVERELY FRACTURED ZONE WITH HIGH GROUNDWATER INFLOW |
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| 鄭文隆、張文城 |
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| 迂迴隧道，繞行隧道，水平長距離鑽探 |
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| 全斷面隧道鑽掘機（ＴＢＭ）的使用為國內正在萌芽的施工技術，並被首次應用在北宜高速公路的坪林隧道工程。因坪林隧道東端的地質構造甚為複雜且破碎，因此以ＴＢＭ施工的過程遭遇極大的困難，尤其是在里程39k+079處遭遇極度堅硬而破碎的四稜石英砂岩層，並伴隨壓力高達20kg/cm2以上的地下水，以每秒約150公升的流量湧入隧道內，造成ＴＢＭ無法順利開挖並停機長達兩年。本文旨在詳細說明施工所遭遇之困難與處理所引用之技術與工法，以為爾後使用ＴＢＭ施工，甚至規劃設計之參考。 |
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| The construction techniques of tunnel boring machine(TBM), which is firstly applied in the Pinglin tunnel of Taipei-Ilan expressway, is founded and been improved domestically. Many difficulties were encountered during the construction of TBM in Pinglin tunnel because of the complicated and fractured geological structure especially at station 39k + 079 of Pinglin pilot tunnel. Large groundwater inflow, I.e. approximately 150 l/s, with high water pressure over 20 kg/cm2 in hard and highly fractured Szeleng sandstone formation was encountered at station 39k+079 and approximately two years has been consumed to solve the geological difficulties since February 1996. This paper is to present and discuss the difficulties encountered and related construction techniques in the Pinglin tunnel in detail in order to upgrade the related techniques in the future. |
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| CASE STUDY ON APPLICATION OF TUNNEL FOREPOLING METHOD IN TAIWAN |
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| 郭奇正、劉弘祥 |
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| 洞口、斷層、剪裂帶、軟弱地盤、先撐管幕工法、先撐鋼管、固結灌漿 |
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| 台灣位處於板塊碰撞交界處，地層年代及地質構造變異性高。近年來大部份隧道工程均位於地層及構造複雜之西部麓山帶、中央山脈帶及雪山山脈帶，因此隧道洞口必須面臨岩盤強度不足及偏壓問題；而隧道沿線亦經常遭遇斷層、剪裂帶及軟弱地盤問題，為克服此種困難地質，除了加強支撐措施之外，另外必須採取各種輔助工法才能順利通過，其中先撐管幕工法是一種較先進而有效的工法，其原理是在未開挖的隧道頂拱部份預先打入一系列先撐鋼管，並施以固結灌漿，使隧道頂拱預先形成一傘狀保護環，俟隧道開挖後，先撐管幕即與鋼支保、鋼線網及噴凝土形成三度空間支撐系統。本文除了詳細說明先撐管幕工法之施工過程之外，回顧國內施工案例並詳細介紹鐵路新觀音隧道施工實例，敘述先撐管幕工法應用於破碎機開挖隧道的情形，最後依據施工經驗提出檢討與建議，以供隧道工程先進們參考。 |
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| Taiwan, located at the contact edge of two colliding tectonic plates, is composed of geological formations highly variable in geologic age and geologic structures of high complexity. In recent infrastructure development, many tunnel projects are concentrated within the western foothill and Hsuehshan Range geologic areas both of which are complicated in their geological features. Tunnelling in these areas is inevitably expected to encounter difficulties at two localities: at the portal areas where shallow overburden of friable rock mass is present; and along the alignment, where adverse effects arising from occurrence of faults and numerous shear zones tend to aggravated the situation. To overcome these difficulties, additional measures besides strengthening of the tunnel support have to be adopted to enable smooth execution of the projects. Tunnel forepoling method, among these additional measures, is one of the promising methods which have been implemented in tunnel construction for years in foreign countries. In tunnel forepoling method, a series of steel pipes is installed at the crown of the tunnel ahead of the driving face and then followed with consolidation grouting to form a protection vault or umbrella in the rock mass before excavation. With the subsequent tunnel excavation and support, the forepoled vault combined with the transverse support has, thus, established a 3-dimensional tunnel support system. This article, besides the details of the construction procedures of the forepoling method, is to introduce some tunnel construction projects, one by TBM and the other using backhoe and hydraulic breaker, those through application of tunnel forepoling method. Finally, we submit a discussion and suggestion according to the construction experience to tunnelling engineer for reference. |
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| AN INTRODUCTION TO THE PILOT TEST OF DYNAMIC COMPACTION |
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| 吳偉康、吳建閩、吳博凱、葉嘉鎮、郭天成 |
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| 地盤改良、動力夯實 |
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| 台塑六輕石化工業區海豐區以動力夯實工法進行地質改良，為尋找最適當的施工方法分別以落距、錘擊間距、夯實能量等不同組合方式進行五種模擬施工。由各種模擬施工之成效檢驗結果發現，其有效的改良深度在地表下9-11公尺範圍內，而改良效果則以施加能量最大的TypeⅢ區最佳，TypeⅠ區次之，且模擬施工的成效與國外相關經驗比較，大致相符。在夯實能量相當的TypeⅡ、TypeⅣ及TypeⅤ區由於規劃之間距及單點錘擊不同，亦產生不同的改良效果，顯示動力夯實工法的施工規劃甚為重要。 |
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| Dynamic compaction technique has been used to improve the soil condition in FPG Sixth Cracking Project. Therefore, 5 patterns of dynamic compaction pilot test have been executed on Hi-Feng site to find the best combination of the drop height, grid spacing and applied energy. The verification results indicate that the effective improvement depth is between 9 and 11 meters. Moreover, the best improvement result is that of TypeⅢ which has the greatest applied energy. And TypeⅠcomes in second. These results correspond well with those obtained from foreign experience. The improvement results of TypeⅡ、TypeⅣ and TypeⅤ, which have similar applied energy, are different due to their grid spacing, drop height, and numbers of drops. The above results clearly show that the construction planning is very important to dynamic compaction. |
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| THE INFLUENCE OF GROUND TREATMENT TO TANK FOUNDATION SETTLEMENT ON RECLAIMED LAND |
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| 王傳奇、鄭智元、劉福生、吳青昆 |
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| 動力夯實、礫石樁、覆土預壓、儲槽基礎、沈陷 |
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| 海埔新生地上構築大型儲槽須面對土壤液化、基礎承載力不足及沈陷量或差異沈陷過大的課題，一般咸認地盤改良是經濟而有效的解決方案。本文擬以動力夯實、礫石樁及覆土預壓三種土壤改良工法於海埔新生地儲槽基礎之應用成果，探討該三種改良工法對土壤壓縮性及基礎沈陷之影響。由現地圓錐貫入試驗及沈陷監測結果顯示，三種工法對於降低新生地土壤壓縮性均有相當成效。其中礫石樁可降低疏鬆砂土層之壓縮性約50至70%，而對於大型儲槽載重造成基礎之沈陷，以覆土預壓之改善效果最為顯著，可降低約80%之營運沈陷。 |
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The construction of large storage tanks on reclaimed land faced problems including soil liquefaction, insufficient bearing capacity and excessive total settlement or differential settlement. It is generally considered that ground treatment is an economical and effective solution. In this paper, the improvement results using dynamic compaction, stone column and preloading are presented and compared in two respects, soil compressibility and foundation settlement.
The field cone penetration test and settlement monitoring results indicated that all of the three kinds of improvement techniques worked effectively to reduce the soil compressibility of reclaimed land. For loose sandy soil, the installation of stone column could reduce soil compressibility for about 50 to 70 %. For the foundation settlement of large tank, the improvement effect of preloading was the most significant , a reduction of 80 % of operation settlement . |
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| BASEMENT UPLIFT DURING CONSTRUCTION |
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| 謝旭昇、林永光 |
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| 地下室開挖、地下室上浮、抽水、加載 |
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| 地下室結構體上浮現象常見於地下一層或兩層之較淺開挖，其發生原因主要是地下水位短期間失去控制，其發生時機常在鋼版樁或鋼軌樁拔除並停止抽水後，暴雨後亦是發生上浮之另一時機。地下室結構體之上浮量一般介於30 ~ 100 cm之間，須設法將上浮之結構體適度壓回原高程以利後續上部結構體之施工。壓回結構體之可行方式包括加載、打設解壓孔、抽水、洗砂等，須視現場土質、地下水及上浮狀況搭配使用以竟全功。 |
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| Basement uplift is a phenomenon not uncommonly encountered for one-story or two-story basement excavation projects. Ground water temporarily out of control is the main culprit for such incidents, and it usually happens following the completion of basement structure, upon which the retaining sheet/soldier piles are withdrawn and dewatering operation ceased. Heavy rainfall in a short period may also lead to basement uplift under certain circumstances. The amount of uplift ranges between 30 ~ 100 cm, and the situation has to be more or less remedied before the construction can be resumed. A number of remedial schemes, including reloading, installing relief holes, pumping and wash boring, are currently available. These schemes can be used independently or in combination, pending on in-situ soil, ground water and uplift conditions. |
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| CASE HISTORY ON PIPING FAILURE AND REMEDIAL MEASURES FOR A DEEP EXCAVATION |
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| 劉國鎮、段紹緯、王劍虹、王瑞芳 |
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| 管湧，灌漿，透水試驗，修復設計 |
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| 本文描述位於臺灣南部港口碼頭之深開挖工程，於13.75公尺開挖完成，在構築大底組紮鋼筋期間，發生管湧破壞案例。針對管湧災變發生經過，原因及修復設計，加以分析說明；修復設計採用填充及止水灌漿，配合降水措施及監測系統完成本工程之修復。本管湧案例導致破壞之原因，可能係由於開挖面下方具有黏土夾層，加上颱風帶來大量豪雨，造成黏土層下方水壓上升，導致管湧破壞。 |
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| This paper presents the sequence, failure mechanism and remedial measures of a piping failure occurring during a deep excavation at a harbor in southern Taiwan. The piping failure occurred after a 13.75 m deep excavation had been completed and after 5 days heavy raining. The causes of the pipping failure could be associated with the presence of a thin clay blanket below the bottom of excavation, together with the rising of groundwater table due to waves and heavy rains brought by a typhoon. After the incident, the remedial measures taken included instrumentation, groundwater pumping as well as grouting to fill cavities and to stabilize disturbed soils. |
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| CASE STUDY OF CORRECTING BUILDING SETTLEMENT |
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| 朱 旭、周黎明 |
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| 工作井、湧水、低壓灌漿、扶正 |
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| 台北捷運板橋線於和平西路工地因工作井發進鏡面破除時突然發生湧水，導致路面下陷及鄰近一棟10樓之建築物發生側傾，本文特針對該建物側傾情形、扶正施工規劃及觀測結果等詳細說明，以供相關工程規劃、施工之參考。 |
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| Taipei MRT for Panchiao Route Project had experienced a piping failure while excavating at the entrance face for shield tunneling in the starting shaft on Ho-ping W. Rd. site. The sudden piping had resulted in ground subsidence and tilt of a nearby 10-story building. For leveling and lifting of tilt building and ground subsidence, a series of remedial program have been performed successfully and are presented in this paper. |
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| ANALYSIS OF LATERALLY LOADED GROUP PILES |
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| 范嘉程 |
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| 橫向力，群樁，樁-土壤-樁互制效應，p-y曲線 |
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| 當群樁之樁距窄小時，承受橫向力之樁群行為受各樁間之互制作用影響極大，此一互制作用可稱為樁-土壤-樁互制(Pile-soil-pile Interaction)或群樁效應(Group Effect)。影響承受橫向力之群樁行為的主要因素為樁材料性質、土壤行為、樁間距及載重方向，其中樁間距及載重方向為控制群樁效應的重要因素。根據前人研究指出，沿橫向載重方向6至8倍樁徑或垂直於載重方向4至5倍樁徑時，群樁效應可不予考慮，樁群中各樁之行為可以單樁來考慮。本文將探討”樁-土壤-樁”互制對承受橫向力群樁行為的影響，除對現有分析方法作一討論外，同時亦介紹一目前最新發展之橫向力群樁分析方法，以提供大地工程師作為分析承受橫向力之群樁的變形及應力行為的參考。 |
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| The laterally loaded behavior of a group pile is affected greatly by the interaction between piles while pile spacing is close. The interaction is termed as pile-soil-pile interaction or group effect. Pile properties, soil behavior, pile spacing, and loading direction are main factors affecting the behavior of a laterally loaded group pile; among which, pile spacing and loading direction are important factors controlling pile-soil-pile interaction. According to previous studies, group effect is insignificant while pile spacing is six to eight times pile diameter along the lateral loading direction or is four to five times pile diameter normal to the loading direction; the lateral behavior of a group pile can be modeled as that of a single pile. This article focuses mainly on discussion of the effect of pile-to-pile interaction on behavior of laterally loaded pile groups. Existing methods for analyzing laterally loaded pile groups are described. In addition, a recently developed concept and methodology for analyzing a laterally loaded pile group is introduced to provide geotechnical engineers with a way to reasonably calculate the stress and deflection of laterally loaded group piles. |
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