地工格網肋條抗張強度試驗條件控制之影響評估

Effects Study of Controlled Testing Conditions for Geogrid Rib Tensile Behaviors

林言融(Yan-Rong Lin)

指導教授 ： 張達德

中原大學/工學院/土木工程研究所/碩士(2003年)

https://doi.org/10.6840/cycu200300659

摘要

地工格網材料之強度特性通常由GRI-GG1單肋強度試驗所求得，然而，相同試驗在規範要求下，由不同試驗人員測得之試驗結果，理論上，試驗結果應相似；實際上，試驗結果常有差異，這對抗張模數影響甚巨，所以在規範要求下，試驗條件選定格外重要，量測抗張模數試驗條件影響因素，諸如量測長度、預拉力、使用不同夾具及應變量測儀器。
因此，本研究為進一步探討三種量測長度與五種預拉力對地工格網性質影響之程度，針對九種不同材質、性質與強度之地工格網進行單肋強度試驗，施加於地工格網之變形速率為50mm/min，試體尺寸為格網單一肋條 (依據GRI-GG1)。
於研究之本文中將呈現下列成果：
1.將量測長度對不同材質、性質與強度地工格網抗拉強度、材料模數與極限應變之影響進行分析，計算折減幅度與增量。
2.提出各種地工格網於三種量測長度與五種預拉力下之最佳量測長度與預拉力。

關鍵字

量測長度 ； 單肋強度試驗 ； 抗張模數 ； 預拉力

並列摘要

The strength and feature of geogrid material is normally obtained by a single rib strength test. In Theory, under same test criteria, even when tests are conducted by varied testing staff, their test results should be similar; in reality, the test results vary most of the time, which affect tensile modulus a great deal. Under the demand of criteria, selecting testing conditions thus is particularly important. The testing conditions of measuring tensile modulus may be affected by gage length, preload, different clamps used, and strain measuring instruments.

Consequently, this research has further explored how much the three gage lengths, and five preloads may affect features of geogrid. With nine different materials of geogrid, single rib strength tests on nature and strength are conducted; deformation speed 50 mm/min is applied to geogrid; the size of test body is a geogrid single rib (according to GRI-GG1).

The article of this research will present the following achievements:
1. Make analyses of their influences of varied materials, nature, strength, tensile strength of geogrid, material modulus and extreme strains in terms of their measuring length, and calculate decrease scale and increase level.
2. Bring up the best gage length and preload of various geogrids under three gage lengths and five preloads.

並列關鍵字

Tensile Modulus ； Single Rib Strength Test ； Preload ； Gage Length

參考文獻

20.謝啟萬，“地工合成材料常用檢測方法簡介”，地工技術雜誌第七十一期，pp. 13-28 (1999)。

21.張達德、林上源，“應變對地工加勁材基性質影響之探討” ，碩士論文，私立中原大學土木工程研究所 (2001)。

22. Ajit D. Kelkar et al, (2000) “Effect of Gage Length and Test Speed on the Measured Tensile Properties of Geosynthetic Reinforcements” ASTM STP 1379,pp.37-46.

26. Bergado D.T., Chai J.C. and Balasubramanism A.S., “Interaction between grid reinforcement and cohesive-frictional Soil”, Proceedings of the International Symposium on Earth Reinforcement Practice, Kyushu University, Fukuoka, Japan, pp. 29-34 (1992).

29.Boyle, S.R., Gallagher, M. and Holtz, R.D., 1996, “Influence of Strain Rate, Specimen Length and Confinement on Measured Geotextile Properties”, Geosynthetics International, Vol. 3, No. 2, pp. 205-225.