 |
|
|
 |
[ 開啟全部內容 ]
[ 隱藏全部內容 ]
|
| DESIGN AND APPLICATION OF AASHTO M 288-96 GEOTEXTILE SPECIFICATIONS |
|
| 胡寶麟 |
|
| 地工織物、地下排水、過濾、分隔、穩定、水土保持、臨時沉泥攔柵、
鋪面織物 |
|
地工織物為柔性之工程材料，於70年代末問世以來，即以線性快速成長，至今已成大地工程解決疑難雜症之利器；但地工織物牽涉到高分子材料、紡織及大地工程，雖為大地工程所應用，但其性質及行為取決於高分子材料與紡織製程，故如何恰當、允當使用地工織物為一重要課題。
本文以AASHTO M 288-96規範為例，闡述地工織物之應用；於特定之應用，地工織物所扮演之功能，及涵蓋紡織及大地工程所應考量之物理、化學及力學因素，需求之地工織物性質，供大地工程師在地工織物應用之省思及參考。 |
|
Geotextiles are soft engineering materials. From the end of 1970, geotextile's application in geotechnical engineering has grown rapidly and become a great tool for solving geotechnical problems. Geotextile includes polymer, textile and geotechnical engineerings, although used by geotechnical engineer, its properties and behaviors are related to polymer materials and textile manufacturing process. It is an important topic on how to use geotextile properly.
In this paper, using AASHTO M 288-96 Specifications explains the applications of geotextile. In the specialized applications, the functions of the geotextile and the factors of the physical, chemical and mechanical properties of geotextiles covered in textile and geotechnical engineering as well as required properties for the application are introduced. |
| |
|
| INTRODUCTION TO THE STANDARD TEST METHODS FOR GEOSYNTHETICS |
|
| 謝啟萬 |
|
| 地工合成材料、規範、標準 |
|
| 地工合成材料為土木營建新興施工材料，其大致包括地工織物、地工格網、地工止水膜、地工排水網、地工粘土毯、地工排水管、地工複合材、及地工泡沫材等八大類，其應用功能包括區隔、加勁、濾水、排水、防漏、保護、及防沖蝕。設計上地工合成材之選用除需滿足其應用功能外，亦需考慮其性能是否可滿足規範之要求，及其於市場上之供應情形及價格等因素。目前地工合成材於工程之應用上已日益普遍，因此本文乃針對地工織物、地工止水膜、及地工格網目前CNS、ASTM、及GRI所包含之相關規範，簡要地敘述，供工程界先進參考。 |
|
| Geosynthetics exclusively are human made new construction materials which have influenced the construction in the areas of geotechnical engineering, transportation engineering, environmental engineering, and hydraulics engineering, etc. The families of Geosynthetics include Geotextiles, Geogrids, Geomembranes, Geonets, Geosynthetic clay liners, Geopipes, Geocomposites, and Geofoams. Geosynthetic materials perform seven major functions：separation, reinforcement, filtration, drainage, liquid barrier, protection, and erosion control. For a particular application design, the ultimate decision usually take one of the three directions：design by cost and availability, design by function ,and design by specification. Since the new materials are widely used in various construction, design by specification is very common and exclusively important when dealing with public agencies. The objective of the paper is to review the current common used CNS, ASTM, and GRI test standards for Geotextiles, Geomembranes,and Geogrids. |
| |
|
| REVIEW OF GEOTEXTILE FILTER DESIGN |
|
| 吳朝賢 |
|
| 織物、過濾、阻塞、遮蔽、設計 |
|
| 地工織物在過濾排水的應用日趨廣泛，其設計方法則日新月異。本文介紹地工織物應用於過濾功能上的考量及近期發展。內容包含過濾原理介紹、影響過濾因子與織物特性之量測方法、過濾準則的檢討、及依據土壤與織物特性及現場條件的設計流程。最後對設計使用者該有的判斷與抉擇作建議。 |
|
| Geotextiles are used extensively to replace granular soil filters in many geotechnical applications. This paper reviews current criteria used in geotextile filter design. Principle concepts, influence factors, methods of characteristic measurement, as well as recently-developed design procedures are included in this review. |
| |
|
| COMPARISON OF FIVE DIFFERENT GEOSYNTHETICS DESIGN CODES |
|
| 林三賢 |
|
| 地工合成材，荷重－阻抗係數設計，凝聚重力法，背拉楔形法，結構勁度法 |
|
| 各種地工合成材設計規範之基本觀念互有異同。有的規範會在某些考量較為保守，而在其餘部分較為開放。本文比較了英國BS8006，BE3/78；法國NF P 94－220，德國DIBt，以及美國聯邦公路協會（FHWA）五種設計規範之基本異同觀點。尤其注重在擋土牆設計方面之比較。 |
|
| Basic design concept of various codes for geosynthetics may be the same on certain points, however, they may also be different on certain other points. The purpose of this paper is to compare the basic design concept of five different design codes, which include UK BS 8006, BE 3/78; France NF P 94-220; Germany DIBt; and USA FHWA codes. The comparison emphasizes on retaining wall design. |
| |
|
| EVALUATION OF GEOTEXTILES AS SEPARATORS IN ROADWAYS |
|
| 蔡文森、R.D.HOLTZ |
|
| 地工織物、道路、分隔層、試驗室試驗、車轍 |
|
| 地工織物(geotextile)為道路分隔層(separator)應用上，除提供分隔(separation)基層與路基之主要功能外，亦提供其它次要功能，如過濾(filtration)、排水(drainage)及加勁(reinforcement)等功能。為能有效地提供上述功能，地工織物埋設於道路中須克服耐久性(survivability)、碎石級配之細顆粒污染(soil contamination)、地工織物開孔阻塞(clogging)與老化(aging)等問題。為瞭解地工織物於道路中之行為，作者等共進行19組試驗室試驗。試驗結果顯示，地工織物若於施工中與設計年限中沒有被穿破或撕裂，地工織物之採用可增加路基承載力，惟地工織物種類與勁度對車轍深度之影響甚微。另水壓計量測結果亦顯示，路基中超額孔隙水壓變化不受地工織物之種類與勁度所影響。另地工織物分隔層沒有被穿破或撕裂，則均能有效地阻止細顆粒從路基進入碎石級配中。雖地工織物分隔層之部份開孔被阻塞，但超額孔隙水壓並不因此而大幅增加，其原因可能係即使地工織物分隔層之部份開孔被阻塞，其透水性仍較其下之路基高，而能充分排除從路基排出之孔隙水。 |
|
To evaluate the performance of geotextiles as separators in roadways, a series of laboratory model tests were conducted to simulate field conditions experienced by geotextiles. In this study, different thicknesses of base courses and geotextiles of various types with various weights were used. The soft subgrades also have different strengths and soil types. These parameters can represent some of the conditions, where geotextiles are used.
In laboratory tests, cyclic loading was applied on aggregates, which were underlain by a geotextile. Underneath the geotextile, a soft soil (clayey soils and silty soils) was prepared by consolidation to simulate a soft subgrade in a field. During cyclic loading, the depression at aggregate surface and porewater pressure within soft subgrade were monitored. In this paper, the performance of geotextiles are evaluated in terms of separation, survivability, drainage, filtration and reinforcing. Based on the results, the separation function of geotextiles are found promising, if they survived under the dynamic loadings. In contrast with control tests (without geotextile), the failure mode of soft subgrade were found to become general failure mode from local failure mode. Therefore, the bearing capacity of the subgrade increased due to the presence of a geotextile. The porewater pressure within the soft soils increased initially and then decreased with the number of loading cycles. The influence of the types or weights of geotextiles on excessive porewater dissipation is found very minimal. No considerable amount of fines migrated through the geotextiles in the laboratory tests. |
| |
|
| APPLICATION OF GEOSYNTHETICS TO WASTE LANDFILLS |
|
| 陳榮河 |
|
| 地工合成材、掩埋場、廢棄物 |
|
| 地工合成材在掩埋場的應用上，扮演著相當重要的角色，其功能包含作為襯墊層、隔絕層、防護層、及排水排氣設施等。本文主要對掩埋場之覆蓋系統及襯墊系統之組成及功能，加以說明；並提出地工合成材在選材、設計、及施工時的一些考量及注意事項；此外，對於地工防水膜的的特性也有詳細的介紹。 |
|
| Geosynthetics play a very important role in application to waste landfills. They can be used as surface layer, protective layer, drainage layer, barrier layer, as well as for gas collection. This paper introduces how geosynthetics are applied as the components of the cover and the liner systems of waste landfills. Some consideration and important issues are also mentioned for material selection, designing, and construction. In addition, the characteristics of geomembranes are described as well. |
| |
|
| LANDFILL HYDRAULIC BARRIER MATERIALS AND METHOD OF EVALUATION BASED ON TECHNICAL EQUIVALENCY |
|
| 單信瑜 |
|
| 掩埋場、阻水層、阻水材料、地工合成材 |
|
| 地工合成材的快速發展有一大部份的原因歸諸這些材料在廢棄物掩埋場中的應用。由於法規的制訂直接導致了地工止水膜的廣泛使用，其後許多其他地工合成材料也陸續被引進掩埋場工程中。但是也因為法規的限制，導致了許多新開發的地工合成材料並不容易被立即應用於掩埋場中；主管機關往往必須針對個案進行材料的評估。近幾年來，美國衍生出一套基於技術相當性的評估方式，非常值得借鏡；本文中將予以詳細說明。文中雖僅就掩埋場中最重要的子系統-阻水系統使用的材料為例做詳細的技術相當性評估介紹。但是這一套原則對於其他子系統如滲出水集排水系統(Leachate Collection and Removal System, LCRS)、排氣系統(Gas Collection System)、甚至是每日覆土(Daily Cover)，都同樣適用。 |
|
| Hydraulic barrier is the most critical component of the bottom lining and final cover systems of modern landfills. There is a wide variety of materials that can be used for hydraulic barriers including synthetic materials made of polymers, natural soils, asphalt, and composites made of some of these materials. The choice of materials has been limited by regulations such that many new geosynthetic products are excluded. Recently, a method for comparing these materials based on technical equivalency has been developed and has been gaining acceptance among the regulatory agencies and the industry. The procedure will be introduced in this paper and will use the hydraulic barrier material as the subject for evaluation. The procedure should also be employed to evaluate other components of the landfill. |
| |
|
| CASE STUDY ON GROUND FREEZING OF CONTRACT CH221 OF THE TAIPEI MRT SYSTEM |
|
| 楊國榮、范陳柏、趙際禮、王錦伍 |
|
| 冷凍工法、凍結管、測溫管、CH221標 |
|
| 冷凍工法主要藉由冷凍液經由埋設於地盤中之凍結管，將地盤中之熱發散於大氣中，以使地盤凍結，達到地盤不透水及增加地盤強度之目的。本文介紹此工法之細節，與其應用於台北捷運系統新店線CH221標2A潛盾隧道受損環片更換之施工案例。 |
|
| The ground freezing technique was used to improve the watertightness and the shear strength of the ground. By transferring the heat in the ground via the brine circulation pipes into the atmosphere, the ground is then frozen. This paper presents the details of ground freezing and the application of this technique to the restoration of the damaged linings of tunnel 2A of Contract CH221 of Taipei MRT. |
| |
|
|
|
|
|
|
|