作者

廖志忠

摘要

台灣由於地質、地形、氣候等諸因素而分佈甚為廣闊的卵礫石地層。近年來，政府及民間積極合力推動各項重大工程建設。此類重大建設無可避免的要構築在卵礫石地層上或其內。由於國內外甚少有在卵礫石層從事大型建設之經驗，大地工程從事人員對於這既不是土壤也不是岩石的地質材料，無論於調查、試驗、分析、設計及施工上都不似岩石或土壤一樣有成熟的理論基礎或實務經驗可供參考。因此，本期地工技術以「、卵礫石層之工程特性」為專輯主題，專輯內刊登七篇精采的相關論文，期盼對台灣地區卵石層工程之進行有所助益。
由於地質常識根基不深，常使大地從業人員於工作上未能完美，因此台灣大學地質系鄧屬予教授於「台灣卵礫石層的地質背景」文內以地質觀點，將台灣卵礫石層的分佈、成因、產狀、形成年代做了詳盡的介紹，相信對於工程師、學界解決卵礫石層工程特性分析或研究上的地質盲點有所幫助。日大工程顧問公司王文祥先生於、礫石層之沈積特徵及量化描述方法嘗試文內由卵礫石層之沈積學切入，嘗試以定量化來描述礫石，相信對於卵礫石層之分類有所助益。
台灣卵礫石之顆粒分佈甚大，無論現場調查，室內或現地試驗皆有其困難性，亦皆甚難掌握其調查成果及其正的工程特性，因此，調查方法、試驗方法的適用性於探討卵礫石層工程特性時皆有必要加以深研。另外，對於卵礫石層的工程性質亦有必要加以有系統的整理以建立一可用的資料庫。因此，中興顧問公司的張吉佐、陳逸駿、嚴世傑、蔡宜璋四位先生於「台灣地區中北部卵礫石層工程性質及施工探討」文內，依地理位置將台灣中北部礫石層分為六分區，並整理出各分區之力學性質及材料組成，以供參考。中興大學土木系褚炳麟教授及潘進明、張國雄先生於「台灣西部卵礫石層現地之大地工程性質」文內，針對卵礫石層之現地調查方法，室內及現地試驗適用性及優缺點加以檢討，並整理出部份西部地區卵礫石層現地直接剪力及平板載重試驗結果。交通大學土木系董家鈞先生及黃安斌教授將礫石土材料室內及現地試驗之檢討及未來可能改善之途撰於「礫石土材料之力學試驗現況與展望」一文內。
榮工處謝玉山先生及劉綉琴小姐所撰之「三義隧道卵礫石層段之施工探討」，針對三義隧道礫石層內之施工方法，施工監測及施工中產生災害的原因加以整理，以饗讀者。另外，三力技術顧問公司謝旭昇博士及王崑瑞先生於「礫石層深開挖案例」中針對三個卵礫石層採用連續壁施工法之深開挖案例，加以檢討，並提出卵礫石層深開挖設計注意事項以供參考。
最後由中興顧問社劉弘祥、黃崇仁及陳怡名三位先生所合撰之「不同型式岩桂及預力地錯於砂、泥岩層內之行為特性探討」，雖非屬專輯主題範疇，但本文依據台灣常用之岩桂及預力地錯於現地試驗之結果，提出軟弱岩石內地岩錯適用性建議，值得參考。

作者

陳世圯

摘要

「地工技術」是一本學術與實用兼顧的優良期刊，對國內地工技術的傳承與擴散作了偉大的貢獻。潘博士希望我寫一點東西與地工界的朋友分享，這是我很大的榮幸。由於我長久在公路局服務，所以就從公路談起。
公路運輸在交通運輸體系中佔有很大的比重，它是中短途客貨運輸的主力﹔而公路則是公路運輸的基礎建設，公路建設是公路運輸發展的主要標桿。台灣地區的公路依據網路結構，大致可分為高速公路、環島公路、橫貫公路、濱海公路及聯絡公路等六大系統﹔若依據行政管理別來分，則可分為國道、省道、縣道、鄉道及專用公路等五大類。路線總長約兩萬公里，公路密度已達每百平方公里為56公里。未來城際間的公路系統將以服務長途客運及快速中長程貨運為主要對象，並以高快速公路網為快速流通之主要幹道。因此，展望未來十年，就國家公路建設而言，將是一個充滿挑戰的年代，也是地工界朋友參與公路建設的一項使命與良機。
公路是一種線形主程，因為它很長，所以常常穿越許多自然條件十分不同的地區。公路又主要是－種地表淺層的建築物，它不僅受到地質、地工因素的影響，也受許多地理因素的影響。因此，公路建設的大地工程相關工作無論在內容、要求與方法上都有其特殊之處。
與公路建設有關的大地工程內容包括選線、路基、邊坡、潛在地質災害、橋樑基礎、隧道工程及築路材料等項目的測勘、分析與設計。公路的測勘設計是在公路網規劃的基礎上，對一條公路附近周密的調查，並蒐集相關資料，經分析比較後，具體確定公路的位置，再進行設計。路線設計是根據該公路的計算行車速度及交通量，結合所經地區的地形、地質等自然條件，確定公路在空間的線形及其幾何元素；另外還有結構設計則是根據公路的設計載重及使用年限，結合當地的氣候、築路材料等情況，確定路基、路面、邊坡、橋樑、隧道等工程實體的結構型式及各部尺寸，以及所需的交通安全等附屬設施。大地工程師在上述工作中都扮演著舉足輕重的角色，而且在整條公路的規劃設計階段，在基礎、邊坡穩定及築路材料方面擔當主角的作用。
一條公路的建設，通常包括規劃設計、施工及養護等三個階段，程序越是前面，大地主程師的重要性及責任越大﹔在施工及養護階段，大地工程師一般負有危險地質預警、天然災害防治或災後整治等責任，其重要性不言可喻。
台灣地區的公路建設，其密度雖然不低，但因為受到地形的限制，仍然以南北向為主軸，東西向者少。不過，為了促進東西部之平衡發展，橫貫中央山脈的公路系統將是未來公路建設的重要目標。又過去公路調查的資料大都零落分散，同時有些因人事吏送，恐已遺失，因此需要有單位，有心人能將這些寶貴的資料建檔，成立地理資訊系統，以供學術研究、未來建設的參考、以及充足國土資訊系統，其意義與價值，絕非金錢可以衡量，期盼大地工程師再為我國工程界貢獻新猷。

英文篇名

GEOLOGICAL BACKGROUND OF THE GRAVEL FORMATIONS OF TAIWAN

作者

鄧屬予

關鍵字

礫石、礫岩、沈積、台灣

摘要

台灣的卵礫石層主要分布在中央山脈的四周，由於中央山脈山高坡陡，岩盤常在經歷輕微的風化後，就崩解成岩塊而隨著山崩下滑，並順著土石流﹑洪流和濁流搬向河川的下游，堆積在河谷、沖積扇、氾濫平原、海灘，乃至於深海中，形成各種型態的礫石。當礫石被後續的沈積層覆蓋，逐漸地深埋於地下後，就會被壓密固結成礫岩。在造山運動的影響下，地表的常會被抬升成河階和台地的蓋層，而深埋於地下的礫岩，也會被褶曲成傾斜的地層，出露在山脈中。
卵礫石層的時空分佈主要是由造山運動來主宰。在新生代早期，台灣是中國大陸邊緣海的一角，沈積物主要來自福建地區。由於福建從中生代晚期以來，一直是個丘陵地，沈積物以砂泥為主，礫石很少，因此台灣新生代早期的地層以砂頁岩為主，礫岩只以細礫薄層出現。但到了上新世以後，蓬萊造山運動逐漸進入高峰期，中央山脈快速隆起，釋出了大量的岩礫，堆積在山脈邊緣的盆地裡，因而累積成厚層的上新統和第四系卵礫石層。

英文摘要

Gravel formations are mainly distributed in the areas surrounding the Central Range of Taiwan. Owing to the high altitude and steep slope, the rock strata of the Central Range often crumble to blocky debris after slight weathering and slide down slope with mass movements. The rock fragments are transported downstream by debris flows﹑ floods and turbidity currents and deposited in the river valleys, alluvial fans, floodplains, beaches, and eventually deep seas. After deposition, gravels may be buried to depth, compacted and consolidated to become conglomerates. If subjected to orogenic influence, the gravel beds may be uplifted as terrace and tableland deposits, or folded as tilted conglomerates.
The temporal-spatial distribution of gravel formations in Taiwan is mainly controlled by orogeny. In early Tertiary time, Taiwan was part of the China continental margin which was covered by sediments derived from Fujian. Since the late Mesozoic time, Fujian has been a hilly terrain which produced mainly sands and muds, and few pebbles. Hence the early Cenozoic strata of Taiwan are dominated by sandstones and shales with only a few thin-bedded conglomerates. After the Pliocene, the Penglai orogeny gradually reached its climax and the Central Range uplifted rapidly. A huge amount of rock fragments were derived from the Central Range and deposited in the surrounding basins to form the thick piles of Pliocene-Quaternary gravel formations.

英文篇名

SEDIMENTARY CHARACTERISTICS AND TENTATIVE QUANTITATIVE DESCRIPTION METHODS FOR GRAVEL DEPOSITS

作者

王文祥

關鍵字

礫石層、沈積構造

摘要

礫石層之沈積構造受控於其所處沈積環境中水力、深度、河床形態等因素，在同一沈積環境中也會有許多不同沈積構造出現。就一般工程規模討論礫石層邊坡問題時常會忽略到礫石層本身沈積環境及沈積構造，其在空間上的變化會對工程設計與施工有著重要的影響，甚或針對礫石層邊坡的調查工作也殊少考慮以上關係。所以目前學者對礫石層邊坡工程性質上有許多歧異看法，其根本原因在於調查記錄方式尚未標準化。本文參考許多前輩的研究成果，嘗試自沈積學角度切入，在簡單介紹礫石層之沈積環境及沈積構造外，依據這些沈積學上的特徵建議一套礫石層量化描述方法以供參考。

英文摘要

Sedimentary structures of gravel deposits are modified by hydraulics, water depth, bedloads etc. of the environments, even in one single area the facies shift very frequently. The sedimentary facies and structures are easily neglected during the discussion of gravel slopes in engineering design, or in the investigating processes. Therefore, different opinions arise, and the actual reason is that gravel slopes are not uantitatively described . After a brief introduction of sedimentary facies and structures of gravel deposits, this paper attempts to suggest one set of quantitative description methods for gravel slopes.

英文篇名

STUDY OF ENGINEERING PROPERTIES AND CONSTRUCTION METHOD FOR GRAVEL FORMATIONS IN CENTRAL AND NORTHERN TAIWAN

作者

張吉佐、陳逸駿、嚴世傑、蔡宜璋

關鍵字

卵礫石層、地下開挖、隧道、灌漿

摘要

台灣地區存在多處之卵礫石層，且愈來愈多的工程分佈於這些區域。為獲得較整體性之瞭解，本文說明各卵礫石層區域之材料性質及工程施工案例。首先依地區性將台灣西部卵礫石層分成六大分區，包括林口台地分區、苗栗分區、台中分區、大肚山分區、八卦山分區及竹山分區，分別探討其材料之物理性質及力學性質。於施工方面，主要討論工程上較常用者，包括深開挖、隧道(鑽掘工法)及灌漿。本文主要目的在提供卵礫石層之特性作為初步設計分析之參考。

英文摘要

With the increase of infrastructure development in Taiwan, more and more constructions will encounter the gravel formations. For a better understanding of the material properties of the gravel formations and the construction techniques, relevant data and cases are collected and reviewed. General discussions are provided in this paper. All data obtained are from the western areas of Taiwan and they are categorized into six groups based on the geological districts namely Linkou, Miaoli, Taichung, Tatushan, Pakuashan and Chushan. The material and engineering properties of the gravel formations are discussed. As for construction in gravel formations including excavation, tunnelling and grouting are all reviewed.

英文篇名

FIELD GEOTECHNICAL ENGINEERING PROPERTIES OF GRAVEL FORMATIONS IN WESTERN TAIWAN

作者

褚炳麟、潘進明、張國雄

關鍵字

卵礫石層、大地工程性質

摘要

由於卵礫石堆積層之大地工程性質與行為異於沖積土層和岩層，加上材料本身的複雜性與顆粒排列之方向性，使得各項試驗結果具有相當大的離散度。而且材料之基本指數性質與其力學性質，以目前的資料尚無法建立其相關性。究其原因，可能是目前國內外對於卵礫石層之探勘、調查、試驗、分類與分析的方法仍未有客觀性與代表性的標準規範可循，以致於常常帶給大地工程師們相當大的困擾。本文從多方面探討卵礫石層合理的現地調查與試驗方法，並藉由收集筆者與其他單位之資料，以瞭解卵礫石層之現地大地工程性質，提供給工程界作為參考。

英文摘要

The geotechnical characteristics and behavior of gravel formations are significantly different from those of alluvial and sedimentary deposits or other rock formations. Due to the facts of complex material properties and orientations of particle arrangement, the results obtained from the laboratory tests and field measurements are quite different and diverse. Up to the present time, the basic data of the gravel formation in Taiwan are still limited. Hence, the reliable relationship between the mechanical properties and index properties for the gravel formation is still under developing. In the authors opinion ,the main reason of the difference may be due to the method of exploration, classification system, testing and analyses used by the engineers are quite different from each other. In other words, there is still lack of standard criteria that can be followed. Therefore, the geotechnical engineers often encounter some problems when deal with gravelly formation. This paper aims to present a rational approach of exploration and testing method for the gravel formation. Furthermore, through the existing data conducted by the authors and others, it is hoped that this paper will stimulate the understanding of the field geotechnical engineering properties of the gravel formation.

英文篇名

LABORATORY AND IN-SITU CHARACTERIZATION OF GRAVELLY SOILS: CURRENT STATUS AND FUTURE DEVELOPMENT

作者

董家鈞、黃安斌

關鍵字

礫石土、室內力學試驗、現地試驗

摘要

國內外有關於礫石土材料之大顆粒材料力學試驗發展至今，已累積相當之經驗，然而現有之礫石土材料力學試驗結果因離散性過大及試驗本身適用性問題，不論在力學行為瞭解或實際工程應用上均有爭議性。本文針對礫石土材料之國內外室內與現地力學試驗過去的發展及現況作一整理，並對礫石土材料力學試驗目前於工程上之應用及未來可能之發展提出建議，以供地工界朋友參考。

英文摘要

A significant amount of experience has been accumulated through years of research and development in characterizing the mechanical properties of gravel materials. However, due to deficiencies of experimental procedures and the scattering nature of test results, there are many controversial issues related to the fundamental mechanical behavior as well as practical applications of gravelly soils. This paper summarizes current domestic and overseas development efforts in laboratory and in-situ experiments on gravelly soils. Possibilities of applying these experiments in engineering practice and their future development are recommended to our peers for their reference.

英文篇名

DISCUSSION ON THE CONSTRUCTION OF SANYI TUNNEL DRIVEN IN GRAVEL LAYER

作者

謝玉山、劉琇琴

關鍵字

卵礫石層、灌漿、先撐鋼管、坍方、超微粒水泥、小管幕

摘要

台灣山線鐵路雙軌改善計劃中之三義隧道北端約有413公尺通過卵礫石層，其中183公尺穿越中山高速公路下方8-20公尺，另一段自東側工作井向南230公尺則進入苗栗丘陵並緊鄰三義斷層。隧道直徑約10.6m，由於地下水位高，開挖前必須先行灌漿，固結並止水，再以先撐鋼管工法完成隧道開挖。本文主要探討後者230公尺之施工方法，從最初每月平均完成5.7m，並遭遇四次隧道坍方之困境，逐漸改善灌漿與開挖方法而獲得成效，始得以達到每月完成26m之進度。文中並將施工成效與高速公路穿越段之超微粒水泥灌漿與小管幕施工作一比較。

英文摘要

The northern segment of the Sanyi Tunnel for a length of 413m with a diametr of 10.6m is being driven through gravel layer. It is a new double-tracked railway tunnel of the mountain line near central Taiwan. The gravel portion could be divided into two sections：a 183m section going underneath the existing freeway with an overburden of 8～20m, and a second section of 230m is driven southward through the Miaoli hilly district. Due to the high ground water level above the tunnel, a pretreatment of grouting and forepiling is recommended before excavation.
This paper describes the tunnelling methods adopted for the 230m section, where the progress was only 5.7m per month at the beginning, and had collapsed four times. Gradually, the progress rate was improved to 26m a month after the grouting and tunnelling techniques were applied. The results were compared with that of the other section underneath the freeway, where the grout of microfine cement and the minipipe roofing were used.

英文篇名

CASES FOR DEEP EXCAVATION IN GRAVEL LAYER

作者

謝旭昇、王崑瑞

關鍵字

卵礫石層、深開挖

摘要

卵礫石層之剪力強度及透水性高於一般之砂、粘土層，因此卵礫石層中深開挖之特性與一般土層不同。本文針對三個位於台北縣卵礫石層中之深開挖進行描述，並說明其與一般土層深開挖不同之處。這些案例指出，卵礫石層對連續壁及支撐造成之應力較低，壁體變形亦小，反而是地下水之滲流控制為連續壁施工及地下室開挖之重點。

英文摘要

The shear strength and permeability of gravel layer are in general higher than those of sandy or clayey materials, and the behavior of deep excavation in gravel layer is different as a result. This paper describes three deep excavation sites located in Taipei county, which were mainly excavated within gravel layer, and the characteristics of monitoring data are discussed. These cases indicated that pressure acting on diaphragm wall and internal struts were relatively small for deep excavations in gravel layer, and the wall displacement was small as well, while the control of groundwater flow was a main issue during diaphragm wall construction and subsequent basement excavation.

英文篇名

STUDY ON CHARACTERISTICS OF APPLYING DIFFERENT TYPES OF ROCK BOLTS AND PRESTRESSED ANCHORS IN SANDSTONE AND MUDSTONE ALTERNATION

作者

劉弘祥、黃崇仁、陳怡名

關鍵字

砂泥岩互層、岩栓、預力地錨、擴孔錨碇型、乾式鑽孔、潛變

摘要

岩栓及預力地錨之行為及效用受地層性質及施工方式影響極大，且近年來其型式已有多方之發展。台灣西南部麓山地區多含地質年代輕之六雙層膠結鬆散砂泥岩互層，其粉土含量及PH值均高，且含膨脹性粘土礦物，具吸水回脹崩解特性，因此乾燥時強度高，一旦受水浸蝕強度則驟降。由於以往於類似地層之岩栓、預力地錨施工案例較少，為瞭解於此種地層開挖隧道及邊坡穩定工程，使用岩栓及預力地錨之適用性，特將台灣常用之九種不同型式岩栓及六種不同型式預力地錨，於現地施作及辦理現地試驗，並探討下列特性︰(1).鑽孔作業、錨碇段材料、型式、灌漿方法，對岩栓及預力地錨拉力行為之影響；(2).在砂泥岩互層中岩栓及預力地錨長期潛變效應；(3).設計安全係數之考慮。
試驗結果顯示採用氣壓乾式鑽孔及錨碇段以擴孔錨碇型式之岩栓及預力地錨，可於砂泥岩互層中達到較理想之拉力強度；另考量長期潛變效應，應採適當之鑽孔、安裝方式及安全係數，方能確切掌握砂泥岩互層中岩栓及預力地錨之拉力行為及安全性。

英文摘要

The effects of using rock bolts and prestressed anchors are highly affected by the geological conditions and the construction processes. In recently years, many types of rock bolts and prestressed anchors have been developed in Taiwan. The young Liushuang Formation of the western foothills geological province in southwestern Taiwan is composed of loosely cemented sandstone and mudstone alternations. Both of their PH value and silt content are high. These alternations also contain expansive clay minerals, and thus show slaking through absorption of water. In consequence, these rocks show high strength when dry, but the strength drops drastically when wet. There is very little case history of engineering application in this rock formation. In order to gain some engineering insights to such rock formations during tunnel excavation and slope protection, in-situ tests were conducted on nine types of rock bolts and six types of prestressed anchors. During these tests, the following engineering characteristics were studied :(1). The effects of drilling operation, materials for the fixing section, type of bolt or anchor, and grouting method on the pulling behavior of rock bolts and prestressed anchors;(2). Long term creep effects when rock bolts or prestressed anchors are installed in sandstone and mudstone alternations; and (3). Considerations for design safety factor.
The test results indicated that applying an expansion end rock bolts and prestressed anchors through dry drilling of boreholes would achieve a more desirable pulling strength in the sandstone and mudstone alternations. Taking long term creep into consideration, appropriate drilling of borehole, adequate installation method and safety factor will enable correct mastering of the pulling behavior of the rock bolts and prestressed anchors in sandstone and mudstone alternations.