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第50期 |
土石壩工程 |
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林宏達 |
1995/06/01 |
90 |
無庫存
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| 廖培明、劉安強、施國欽 |
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| 橫向集水管、地下水排除、地滑 |
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| 地下水排除是最有效的地滑整治工法之一。傳統的排水工程，包括橫向集水管、集水井、排水廊道等，都是仰賴φ=50～76mm的PVC集水管來執行滑動體及滑動面附近地下水的排水任務，但此等集水管經過兩年左右的使用後，時常會發生阻塞，而大幅降低排水功能。大口徑橫向集水管為一φ=400mm的集(排)水鋼管，根據1991～1993年在日本沖見地滑試驗區所觀測到的資料，包括排水量和水溫、觀測井內之地下水位、及降水量等，得知大口徑橫向集水管的排水效率並未逐年遞減，反而是有漸佳的徵兆，表示日後在整治地滑時，又多一種整治工法可供選擇。 |
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Subsurface drainage is an effective solution to correct or stabilize a landslide. The funtcion of conventional subsurface drainage measures, including horizontal drains, collection wells and drainage tunnels, is mainly carried out by PVC drainage pipes (φ=50～76mm). About two years after the installation, these PVC pipes are often clogged, and the effectiveness of the subsurface draingage system is substantially reduced.
To prevent the clogging problems resulting from the usage of relatively small diameter PVC pipes, the use of large diameter horizontal drain (φ=400mm) is proposed.
The proposed horizontal drain is made with steel pipe which is tested at Okimi landslide test site in Niigada Prefecture, Japan. The test items include drainage capacity and its accompanying temperature, groundwater level inside the monitoring well, precipitation, etc. The test results indicate that the drainage capacity of the proposed large diameter horizontal drain is not reduced over three years (～1993). Conversely, the results show an improvement in the groundwater drainage. Encouragingly, the test results provide us with an alternative in selecting the subsurface drainage measures. |
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| 陳錦清、高憲彰 |
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| 土石壩、地質調查、築壩材料 |
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| 土石壩屬於柔性壩體，適合地震區域及較差之地質條件，且其材料就地取材，設計也因地制宜，合乎經濟要求，因此被廣為使用。因材料的品質與數量必須滿足築壩之要求，故材料調查與評估為土石壩工程的重點工作之一。本文旨在介紹分區土石壩各區之功能及其材料要求重點，闡述進行地質調查之方法與內容，並且以建民水庫為例，評估築壩材料之品質與數量，提供工程界參考指教。根據建民水庫細部規劃築壩材料調查報告，其材料品質與數量經過各項的評估後，大致上均能符合築壩材料之標準，唯在後續階段需提高調查精度及增加部份試驗項目，使整個評估更臻完善。 |
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| Earth dam is a better choice for dam built seismic or/and poor geological conditions zones compared to concrete dam. Generally, it is quite flexible and economic for earth dam construction with materials available near the dam site. In this paper, the required material quality and quantity for different parts of earth dam are described. Investigation and evaluation of materials for the Chien-Ming reservoir dam are particularly discussed. |
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| 吳偉康、林曉宗、莊賢達、謝勝彥 |
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| 土石壩、監測、孔隙水壓、施工含水量、沉陷、位移 |
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| 土石壩因築壩材料性質之不確定性，目前大壩之設計與施工均採經驗與理論並重之方式辦理，故所有土石大壩均設置監測儀器以偵測施工期間、初次蓄水及長期運轉期間壩體可能發生之不正常行為。本文首先介紹分區型土石壩之一般監測項目與目的及規劃之考量，並以一實際案例加以說明。如何利用監測結果瞭解壩體施工期間及將來預期之行為，則為監測結果評估之最重要工作，本文利用一實際例說明施工期間壩體孔隙水壓、沉陷及位移之估計方法。 |
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Due to the uncertainties involved in the behavior of dam construction materials, semi-empirical and theoretical methods were employed in the design and construction of earthfill dam in the current practice. Instrumentation is an important measure to detect the problems which might occur during construction, first filling and long term operation. This paper describes the items, purposes and consideration in instrumentation program for a zoned earth dam. A case history is used to illustrate the design consideration. How to interprete or
predict the performance of dambody using monitored data is the most important aspect of a instrumentation program. The results from a case history were used to illustrate the methods of predicting pore pressure generation and the developments of settlement and deformation of dambody during construction. |
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| 林宏達 |
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| 含水量，土壩，孔隙壓力，最佳含水量 |
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| 夯實含水量對土壩施工中及完工後之行為均構成影響，即便是含水量控制在施工規範規定的含水量範圍內，含水量的變化仍將對大壩行為顯現差異，本文蒐集一些國內土壩施工案例，探討含水量對壩心孔隙壓力的生成、壩體安定分析、壩體沉陷及壩體之滲透性等影響，綜合上述影響，建議在可確保施工階段安全的前題下，將含水量控制在最佳含水量略偏濕側對大壩整體而言較合適。 |
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Water contend of compacted fill inside an earth dam may influence the
preformance of the dam during and after construction. Minor change in water content may cause significant difference in preformance of the dam even when the water content is kept within the allowable range as specified. Case studies on several domestic earth dams have been performed. The results are discussed hereby regarding the influence of water content on build-up of pore water pressure in the core of the dam as well as on the stability ,settlement, and permeability of the dam. The water content is recommended to be kept slightly larger than optium water content, providing the dam is stable during construction, in order to result in
better preformance of the dam. |
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| 包承綱 |
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| 土石壩，地震力，動態分析 |
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| 土石壩在地震作用下之反應，常受壩體材料、壩形、基礎地質、壩址地形及地震特性等複雜因素之影響，因此在進行壩體動態反應分析時，常須作適當的假設及簡化。本研究之目的，在探討土石壩受震時之動態行為，主要研究項目有四部份，包括分析模式，壩體材料、蓄水庫及地震強度等對壩體動態反應之影響。研究結果顯示，土石壩之動態分析可以粘滯邊界有效模擬土壤無限延伸之特性而流體應被納入分析模式。壩體動態反應受壩殼材料變化之影響較壩心黏土材料性質為大。地震強度較大時，壩體基本振動週期較長，然動態放大函數之放大倍數反而較小，且一般土石壩壩殼坡度甚緩，其動態反應受垂直向地震之影響亦較水平向地震為大。 |
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The seismic responses of earth dams are affected by the construction material properties and geometric configuration of the dam, the geology and topography of the site, and the characteristics of earthquakes. They are so complicated that adequate assumptions and idealizations may be necessary to be made to perform the dynamic analysis of earth dams under seismic forces. The main purpose of this research is to investigate the dynamic behavior of the earth dam. The boundary type of analytical models, the variation of shear moduli, the water level of reservoir, and the intensity of seismic force are all studied to evaluate their influence on the seismic responses of the earth dam. Results of this investigation show that viscous boundaries may beeffectively used to simulate the infinitely-extended characteristics of soil, and the fluid in reservoir need to be included in the analytical model. The seismic responses of the earth dam are influenced more by variations of material in the shell part than the clay material in the core part. The fundamental vibration period is longer although the dynamic amplifica-tion is smaller for a larger seismic intensity. Since the slope of the shell part is usually not sharp, the seismic responses of an earth dam are influenced more by the vertical than the
horizontal seismic loads. |
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