 |
|
|
 |
 |
第14期 |
地錨設計與施工 |
可選購電子書 |
游坤 |
1986/04/01 |
90 |
無庫存
|
[ 開啟全部內容 ]
[ 隱藏全部內容 ]
|
| DESIGN CONSIDERATIONS AND TESTS OF GROUND ANCHOR |
|
| 歐晉德 |
|
|
|
地錨在土木工程上之應用已近五十年歷史，但其應用效果受土層性質、施工方式等之影響極大，在目前之設計理論上，仍難完全統一，在過去十年來，各國工程界對地錨的施工標準逐步改進，並且對工程設計之安全度亦漸趨嚴格，其應用範圍更泛蓋了拉力基礎、邊坡穩定、加筋土、海岸構造、隧道工程等，可謂極其廣泛，鑒於國內工程水準之日益提昇，目前地錨之應用亦大幅度增加，乃藉本文對現行之設計觀念，考慮重點以致安全係數之選擇標準以及施工檢驗法等作一綜合說明與討論，以供參考。
地錨之主要功能在於將拉力傳遞至轉堅實的地層中，如圖一所示，地錨之主體分成以下幾個主要部份。
（1）鋼鍵（Anchor Tendon）－－為傳遞拉力之主體，係由數根鋼線或鋼棒（Steel Rod）所組成。
（2）錨碇端（Anchorage）－－於鑽孔之後端，於鋼鍵安裝後，以水泥灌漿固定鋼鍵於孔內，與四周土層緊密結合，形成錨碇作用，亦稱為固定端（Fixed Length），其灌漿通常稱為主要灌漿（Primary Grout）。
（3）自由端（Free Length）－－鋼鍵之前端以保護鞘將鋼鍵與地層分開，使鋼鍵得以自由伸長受力，此部份鑽孔以次要灌漿（Secondary Grout）封孔，用以保護地錨不致鬆動與受腐蝕。
地錨通常以斜角裝設於地層中，與擋土結構合併使用，以保持邊坡之穩定，必要時亦有以垂直角度裝設，以保持構造物於一定之基面上，如拉力樁一般使用。 |
|
| The paper reviews briefly the design methods of ground anchor currently adopted in the general practice around the world. The limitations in the application of the various theoretical approaches in different ground condition have been discussed. The methods of loading test specified in the various Design Manuals, Codes or Standards for the construction control of ground anchor have been summarized also in some detail. |
| |
|
| ANCHOR──DESIGN, CONSTRUCTION, STRESSING AND TESTING |
|
| 曹治宗、張吉佐 |
|
|
|
| 岩錨由於具有效性、經濟性及易控制性之優點，自西元1934年初次用於阿爾及利亞Cheurfas大壩加高後，即廣泛地應用在大地工程上諸如大型地下開挖及山坡穩定等。岩錨係一結構單元，將一特定之拉力以特定之方向穿過結構物至岩盤內部，使結構物與岩盤間成一體，藉以提高結構物或岩盤之安全性。 |
|
| Rock anchor is very useful in increasing the stability and safety of rockmass, rock structure and structure which is sitting on rockmass. It is owing to the applying a compressive stress within rockmass or between rockmass and structure in order to combine the rockmass or rockmass and structure as a continuous body so as to increase the strength of rockmass and to decrease the influence of weak plane on the stability of rockmass, rock structure or structure. In this paper the design, construction, stressing and testing of anchor are introduced. Several reference data of anchoring, such as the recommended strength of allowable working bond, working bonds between rockmass and cement grout, and the bond between tendon and cement grout, are also presented in this paper. |
| |
|
| THE QUALITY CHECK-UPS OF THE PRESTRESSED ANCHOR AND ITS IMPROVEMENT IN THE ROUTINE ACCEPTANCE TEST |
|
| 張清秀、王文禮 |
|
|
|
| 台灣近年來隨著經濟之繁榮與需要，建築物地下基礎之開挖規模逐漸增大，地下工程之設計日趨複雜，造成地下結構體之構築與基礎開挖時內部支撐配置愈趨困難，因此，採用地錨背拉支撐工法之可行性則廣泛被考慮。惟台灣工程界鑑於過去少數預力地錨工程失敗之經歷，因此對採用此種施工方法總是持著特別謹慎之態度，其實在國外已有工程採用背拉式地錨施工，開挖深度達地下33公尺深者（歐晉德等，1983），相信只要增進施工時對地錨之品管，加上配合開挖工程進行中周詳之觀測，以檢核地錨之預力強度是否合乎設計之安全標準，地錨背拉式支撐工法之效果在許多深基礎開挖情況下必較內部支撐工法為有效。本文針對地錨之施工品管作概略的介紹，引述有關預力地錨拉力實測之案例，予以整理分析，以期獲得一有效之預力地錨負荷值之檢核與改善方法，使工程人員對地錨之施工品管有進一步的認識，俾能破除心理障礙，樂於接受及採用此一經濟有效的支撐方法，則亦是筆者撰寫本文所樂於期盼獲得的一些成果。 |
|
As part of the quality control procedure, all the prestressed earth anchors are to be checked to see if the prestress loads meet the design requirements. This step is usually called acceptance tests for the prestressed earth anchors.
In general the prestress load applied on the prestressed earth anchors is measured by the pressure gage of the hydraulic jack during the acceptance tests. However, due to tendon friction and other operation difficullies, the reading from the pressure gage usually does not correctly reflect the load transferred to the earth anchor. Therefore, load cells are introduced to measure the prestress load and serve as a check to those measured by the pressure gage. Nevertheless, because of the accuracy of the load cell and its measuring apparatus, the incorrect arrangement of the load cells in contact with the anchor plate, or the insufficient stiffness of the anchor plate itself, the accuray of prestress load measurement using load cells remain to be a problem. Three cases of earth anchor acceptance tests are described in this paper. The problems encountered in those cases are discussed and analyzed by the authors. An improved method which can measure the prestress load more precisely is also presented. |
| |
|
| INTRODUCTION OF SOIL ANCHORS IN NATIONAL THEATER AND CONCERT HALL PROJECT |
|
| 林泰煌 |
|
|
|
預力地錨常用於（1）岸壁船塢之背拉系統，（2）邊坡穩定之錨定加強，（3）深開挖基礎與船塢底部之抗浮系統，（4）試樁之錨定，（5）建築物地下室擋土背拉系統，（6）其他特殊抗拔錨定。
國家劇院與音樂廳結構體工程施工時曾應用預力地錨於（1）兩廳院地下室擋土背拉系統，（2）音樂廳軌道型塔式吊車之防颱錨定，（3）吊裝兩廳院鋼屋架之起重吊桿之地面錨定，均能圓滿達成預期效果，本文將地下室擋土地錨之使用情況說明如後。 |
|
| A simple description about the design considerations, loading tests and the different applications of soil anchors were given in this paper. The results indicates that soil anchor is the best alternative method of ground support in the construction of the basements of national theater and concert hall project. |
| |
|
| THE CONSTRUCTION AND THE MONITORING OF EARTH ANCHORS IN VETERANS GENERAL HOSPITAI-VACRS |
|
| 吳國安 |
|
|
|
鑒於地錨式之支撐系統，可獲得完全開放的開挖面而使得基礎開挖作業所受的影響可降至最低，故近年來已逐漸為工程界所接納，尤其是運用在深基礎開挖的工程。同時由於基礎開挖的規模日益擴大，對於擋土設施的穩定性亦日趨重視，一般均設置監測系統作為評估開挖工程安全性之依據。
本文所介紹之基礎開挖深度達地表下16公尺，故應屬深基礎開挖工程，此工程係採用場鑄排樁做為臨時擋土壁，並利用預力地錨維持擋土壁之穩定性，並裝設電感式荷重計（Load Cell），以檢測地錨之受力情況。本文將就此工程中地錨之施工及觀測作一介紹與檢討。 |
|
In order to have an effective retaining system for the foundation excavation, which is 140m ~100m in plan and 16 meters in depth, of the central ward of VGH-VACRS, bored piles of 100 cm in diameter with strand type prestressed earth anchor system were used.
Installation procedure as well as the monitoring system of the earth anchor system were briefly described in this paper. Observation results were also briefly discussed. |
| |
|
| AN INTRODUCTION TO THE CONSTRUCTION OF DEEP EXCAVATION IN URBAN AREA-THE DESIGN, TESTING AND CONSTRUCTION OF GROUND ANCHORS FOR THE NEW NATIONAL TAIWAN UNIVERSITY MEDICAL COMPLEX. |
|
| 趙基盛、陳福勝 |
|
|
|
由於都市之極度發展，活動及使用空間日益匱乏，致使土地之使用價值升高，為求土地之有效利用，市區內之建築物越建越高，大規模之超高層建築物則越來越多，建築物之荷重亦隨之增大；為使建築物基礎施工費用能作更有效之利用，並能增加使用之空間，工程設計時漸以增加地下室之層數，同時採用補償式之筏式基礎，取代費用甚昂之樁基礎，導致大規模之深開挖亦越來越多，致使開挖施工時對鄰地結構物所造成之影響，亦漸趨嚴重並廣受大眾重視，因此深開挖擋土支撐系統之選擇得當與否對於基礎施工之成敗影響甚鉅，一般選擇擋土支撐系統時除須考慮地質情況、施工費用及工期等因素外，開挖對鄰地之影響亦為主要因素之一。
國內深開挖之案例甚多，其中絕大部份皆採用橫擋支撐系統（內撐法），而預力地錨（背拉法）應用於國內之基礎開挖施工雖有十餘年之歷史，惟採用之案例並不多，較具規模者僅有台北市亞洲世界大樓、台北市名人世界大樓、仁愛醫院及台大醫學院主體工程；其中以台大醫學院主體工程（長180公尺、寬140公尺、深15.7公尺）規模為最大，採用之地錨長度最長約63公尺，因此於設計時，針對地錨承載力之判斷及其施工性，均應審慎之調查及分析；本文將本工程預力地錨設計之過程加以介紹，並將施工資料提供作為爾後相關設計及施工工法選擇之參考。 |
|
| This paper presents the design and construction of the multi, tied diaphragm wall for the foundation excavation of the new National Taiwan University Medical Complex in Taipei. The building will reach 74 meters above and 17 meters below ground level. A 70-cm thick, 27-m deep diaphragm wall with earth anchros serves as the retaining structure of the 180-m long, 140-m wide foundation excavation. The paper describes the main factors concerned in the selection of retaining system, the evaluation and testing for the bearing capacity of ground archors, the sequence of construction, and practical experience gained during construction. |
| |
|
| INTRODUCTION OF PRESTRESSED EARTH ANCHORING SYSTEM FOR THE TAIWAN UNIVERSITY MEDICAL CENTER |
|
| 陳秋聲、陳昇元 |
|
|
|
台大醫院整建計劃主體大樓係位於台北市中山南路與仁愛路口（原台大醫學院址內），該新建大樓佔地面積達24,000平方公尺，地下室開挖深度15.7～17.7公尺，為一地下3～4層，地上15層之建築物，地下室之周長達620公尺，為一長約180公尺，寬約140公尺之矩形基地，可謂在亞洲地區少見之大基地，乃為亞洲最大之地下室工程之一。
本地下室之施工，如採用慣用之鋼支撐工法時，由於基地之週長至大且開挖深，對於鋼樑之斷面要求、防止挫曲及中間柱之間隔、深度等均難予控制，因此考慮採用背拉式預力地錨工法之施工以達到經濟、安全及縮短工期之目的。 |
|
| The foundation excavation of the medical center is 164,000 m2 in plan and 15.7 to 17.7 meters in depth, and diaphragm wall together with earth anchor served as retaining structure. 1735 earth anchors, with maximum length of 62 meters, were prestressed up to 65 tons. The installation of the anchor system, results of loading test, and an overall evaluation of this project will be briefly reviewed. |
| |
|
| TAIPEI RAILWAY UNDERGROUND PROJECT DESIGN AND CONSTRUCTION OF UNDERPINNING FOR AI-KUO W. RD., OVERPASS BRIDGE |
|
| 高聰忠、王祥騮、王春煌 |
|
|
|
| 目前正興建中之台北市區鐵路地下化工程西隧道自北門至萬華段係沿著現有縱貫鐵路西側施築，在小南門附近須穿過愛國西路陸橋下方，而該橋之P10橋墩正好位於隧道範圍內（圖一及圖二）。對於P10橋墩與隧道主體結構之衝突，地鐵工程處決定採用托底法，將P10橋墩之荷重傳於隧道兩旁之連續壁上。本文係就設計時的考慮因素、施工概況以及施工安全觀測系統作一簡要說明。 |
|
| Taipei Railway Underground Project is under construction at present time. The west tunnel from Peimen to Wanhwa is constructed along the west side of the existing TRA railway. A section of the west tunnel near Hsiao Nanmen is crossing beneath the existing Ai-Kuo West Road Overpass Bridge. The bridge pier（PLO）is located inside the tunnel. Taipei Railway Underground Project Office（TRUPO）has decided to underpin the pier and transfer the pier load to exterior retaining walls of the tunnel. This paper presents a brief description about the design considerations, construction steps, and the instrumentation systems of this project. |
| |
|
|
|
|
|
|
|