砂土地盤皂土液灌漿的室內模型試驗之研究

The Study of Fracture Grouting in Granular Soil with Bentonite Grout

張亨萃(Heng-Tsui Chang)

指導教授 ： 倪至寬

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2005年)

https://doi.org/10.6841/NTUT.2005.00067

摘要

在台灣土木工程中，灌漿工法常用來降低地盤滲透性及提昇地盤強度，但由於地盤狀況複雜，常導致灌漿成效難以掌控，又灌漿工法之相關設計，如漿材種類、灌漿壓力、灌漿量等參數仍需依賴施工人員之經驗，而欠缺實際原理依據，因此，若能藉助室內灌漿模型試驗，將試驗所獲得之成果建立及彙整成灌漿資料庫，回饋至現地設計與施工之用，作為現地灌漿作業之依據，可提昇工程品質及降低災變的發生。
本研究係針對皂土漿液（材），配合五種濃度之皂土液（2、2.5、3、4及5%，wt.%），進行基本性質試驗，包括比重試驗、泌水試驗及黏滯度試驗，並且選用不良級配砂土（SP），製作疏鬆與緊密試體（直徑3.82公分，高度36.9公分），透過自行建製之可灌度試驗設備，評估低稠度漿液（2%）對試體的滲透能力。最後，再由室內灌漿模型試驗設備，利用同樣的砂土，以乾式霣降方式，製作一直徑93公分及高度142公分的砂土試體，經模擬地下飽和砂土的應力狀況後，選擇濃度2.5%皂土液進行室內低壓灌漿試驗，配合監測資料與試體開挖的結果，探討灌漿壓力、灌漿流量與灌漿型式間的關係。
由本研究結果得知，皂土漿液穩定性與皂土稠度及靜置時間有密切關係。在流變性質上，皂土漿液屬賓漢塑性流體，可利用雙曲線模式描述其流變行為；對不良級配砂土（Cu=3.71，Cd=0.86）而言，因漿液受限於顆粒尺寸及漿液黏滯度，導致無法以滲透方式改良試體而是呈劈裂型式。

關鍵字

可灌度試驗 ； 黏滯度試驗 ； 賓漢流體 ； 組合律

並列摘要

Grouting is a routine procedure used to decrease permeability and to increase the strength of soil in Taiwan. However, it is difficult to predict and to confirm the effect of grouting due to complex nature of soil deposit. In addition, the grouting parameters, such as grout type, injection pressure and injection rate, are mainly based on experience. Therefore, an indoor grouting chamber facility is established and grouting simulation can be conducted inside the chamber. The grouting results can provide a data base and may provide valuable information regarding to planning, design, grouting and evaluation of permeation and fracture grouting.
The grout made with water-to-bentonite ratios (W/B) of 2, 2.5, 3, 4 and 5% is tested for its physical properties of specific gravity, stability and rheology. A poorly graded sand of relative density 25% and 85% is used to prepare the sample with a diameter of 3.82cm and a height of 36.9cm. The bentonite grout with W/B of 2% is injected to evaluate the penetrability. At last, a large cylindrical sample with a diameter of 93cm and a height of 142cm is made of the same soil. The bentonite grout with W/B of 2.5% is injected while the grout pressure and grout take are monitored and recorded. The sample is excavated after the curing. The grouting mechanism is discussed along with all the monitored data.
In this study, the stability of grout relates to its consistency and setting time. The grout behaved like the Bingham plastic fluid and the hyperbolic model may be described its rheology behavior. Due to the particle size and viscosity of bentonite grout, fracture grouiting (not permeation grouting) is observed in a poorly graded sand with Cu of 3.71 and Cd of 0.86.

並列關鍵字

penetrability test ； viscosity test ； Bingham fluid ； constitutive law

參考文獻

[58] 林任峰（2005），超細水泥漿液滲透灌漿模式之研究，碩士論文，國立台北科技大學土木與防災研究所，台北。

[66] 趙基盛、陳福勝與何泰源（1994），「藥液灌漿工法之設計」，地工技術，第47期，第5-21頁。

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