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第108期 |
高壓噴射灌漿/地盤改良 |
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王繼勝 |
2006/06/25 |
150 |
無庫存
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| THE DESIGN AND CONSTRUCTION OF SUPER JET GROUTING METHODS |
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| 廖惠生、余明山、陳敏雄、劉明欽 |
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| 高壓噴射灌漿、超高壓噴射灌漿、地盤改良、品質管理 |
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| 台灣由於地狹人稠，為求土地更有效率之應用，無論是深開挖或潛盾隧道工程均有朝大深度發展之趨勢，灌漿深度時有超過40公尺以上，傳統之高壓噴射灌漿工法已不敷使用，因此有超高壓噴射灌漿工法之引進及應用。本文首先介紹各種超高壓噴射灌漿工法基本原理及工法差異和限制，其次探討設計及施工應注意事項，並進一步檢討目前施工品質成效檢驗方法及判定之問題，提供類似工程設計及施工之參考。 |
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| In order to make efficiency use of the congested land in Taiwan, the current trend is towards deep depth of excavation or shield tunnel. The super-jet grouting methods have been introduced since the traditional jet-grouting method is not useful enough for grouting depth over 40m. This paper introduces the difference between several theories of super-jet grouting and its limits, moreover, the key points in design and construction are discussed in the paper. The experimental methods of checking construction quality and the problem during judging will also be presented for reference. |
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| IN SITU TEST PROGRAM FOR DOUBLE TUBE JET GROUTING METHOD |
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| 研究委員會 |
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| 高壓噴射灌漿、二重管工法、現地試驗 |
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| 為瞭解高壓噴射灌漿所能形成的樁徑及樁體品質，數家二重管高壓噴射灌漿專業廠商參加在台北捷運蘆洲機廠基地舉辦的試灌研究計畫。每一廠商都先行預測在蘆洲機廠特定地層及GL-30m條件下所能形成的樁徑，並自行規劃施工參數，進行施工。試灌作業分為皂土樁及水泥樁，皂土樁是噴射皂土漿並以超音波檢測噴射切削形成的孔徑。水泥樁則以鑽心取樣方式檢驗樁體品質，此外也應用CPT調查高壓噴射樁週邊土壤受高壓噴射施工的影響範圍及影響程度。研究發現專業廠商在切削孔徑方面的能力甚佳，即使是GL-25m深度以下，SPT N=8之粘土層都可切削出直徑介於0.75m~2.1m之孔洞，但是水泥樁體的品質卻不理想。研究結果指出在某些限制條件下，高壓噴射灌漿可能無法形成一個類似圓柱體的水泥樁體，工程師應有此認知。 |
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An in-situ test program on double tube jet grouting was carried out at LuZhou depot, Taipei MRT by four local contractors. Purpose of the test program was to validate the diameters and integrity of the jet grout piles. Soil condition at the test site consists of medium stiff silty clay and medium dense silty sand. Jet grouting was conducted within specified layers (<30m), and each contractor was required to develop his own grouting plan as well as the associated grouting parameters.
The test program was carried out in two stages. The first stage used bentonite slurry as the cutting fluid to form jet grout piles, and the pile diameters were later verified by ultrasonic sounding. The second stage used cement slurry instead, and cored samples were taken to examine the quality of jet grout piles. In addition, CPT tests were conducted near the jet grout piles in an effort to identify the extent of ground disturbance induced by jet grouting.
Test results showed that the local contractors are very efficient in cutting holes even in medium stiff clay at depths below GL.-25m. Jet grout piles with diameters ranging from 0.75m to 2.1m can be formed, though the integrity of piles is generally poor. Test results further indicated that under certain circumstances shape of the jet grout piles are far from an ideal cylindrical one, and it is advised that design engineers should bear this in mind.
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| IN SITU TEST PROGRAM FOR TRIPLE TUBE JET GROUTING METHOD |
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| 研究委員會 |
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| 高壓噴射灌漿、三重管工法、現地試驗 |
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| 本文探討CJG及X-Jet這兩種三重管高壓噴射灌漿工法，應用在台北盆地，改良GL-19m~GL-39m地層的施工案例。這兩則案例都是在正式施工前先做皂土漿試灌，利用超音波檢測切削形成的孔徑，據以決定有效樁徑及改良樁體配置，再針對實際施工結果於三樁重疊處鑽心取樣。研究結果發現，雖然樁體配置已做較保守考量，亦即樁心與樁心間距已較切削形成孔徑大幅縮小，但是鑽心取樣顯示的實際改良成效仍與設計或施工規劃預期的成效有很大落差。工程界須正視此一問題，研擬妥善的對策才能減少災變發生。 |
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| This paper discussed results of CJG and X-Jet triple tube jet grouting at a construction site in Taipei basin. Ground between GL.-19m and GL.-39m was jet grouted. Test piles using bentonite slurry as the grouting fluid was constructed first, and ultrasonic soundings were carried out to verify the diameter of test piles. The results of ultrasonic sounding were used as a design basis for the layout of production piles. After completion of the production piles, cored samples were taken at the overlapping area of adjoining piles. Careful examination on the cored samples showed that quality of the improved body was no where close to the design requirements, though a conservative approach had been adopted in designing the diameter and layout of jet grout piles. It is advised that this finding should not be overlooked by the design engineers, or the safety of construction may be in jeopardy. |
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| CASE STUDY OF JET GROUTING EFFECT ON ADJACENT GROUND AND DIAPHRAGM WALL DISPLACEMENT |
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| 林士誠、林宏達、郭晉榮 |
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| 灌漿、攪拌樁、深開挖、連續壁變形 |
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| 本研究針對一個採用高壓噴射攪拌(JMM)工法之地盤改良深開挖案例，進行一系列之監測及試驗來探討改良樁施作時對四周土壤及連續壁行為之影響。試驗結果顯示，灌漿後樁間土壤有傾向脆性行為，而強度較灌漿前略為增加。另由監測結果顯示，(1)灌漿時連續壁可能產生顯著之外擠變形，此外擠變形會因靜置而有回復現象，而其回復比約在18%~22%之間；(2)灌漿引致之外擠變形對後續開挖變形影響很大，連續壁變位會從朝向開挖區外逐漸變化至朝向開挖區內；(3)灌漿時鑽孔四周土壤會產生相當大之位移，尤其距鑽孔約1.0m處時之最大土壤側向位移量可達6.2cm；(4)灌漿施作會激發大量孔隙水壓，距鑽孔愈近被激發之超額孔隙水壓力也愈大，加上超額孔隙水壓之水壓力可達常時水壓之1.5倍。 |
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| In this study, a basement excavation case in Taipei using the JMM jet grouting technique was investigated. Besides regular instrumentation, in-situ and laboratory tests were also conducted both before and after grouting to investigate the effects of jet mixing on the adjacent soils and diaphragm wall displacement. Testing results showed that the soil between the jet grout piles exhibits brittle behavior and slight strength increase. The monitoring results showed that (1) jet grouting would induce significant outward diaphragm wall displacement, and this wall displacement would rebound after some elapsed time, with a recovery ratio of 18%~22%.；(2) Jet grouting had tremendous impact on the diaphragm wall displacement during the subsequent excavation, the displacement profile would gradually move from the unexcavated side toward the excavated side； (3) Soils adjacent to the grouting borehole exhibited large displacement, and the maximum lateral soil displacement recorded adjacent to the jet-mixed piles was about 6.2cm.；(4) During jet grouting, the excess pore water pressure of adjacent soils increased significantly, the closer the larger with a maximum value of about 1.5 times the in-situ pore water pressure. |
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| THE PRELIMINARY STUDY OF SLEEVE GROUTING IN GRAVEL FORMATIONS |
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| 陳瑞禾、林書田、吳以超 |
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| 卵礫石層、雙環塞灌漿、滲透理論 |
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| 卵礫石層屬一複合材料地層，其性質受卵礫石及細料之含量、分佈及性質之影響而異，且卵礫石層透水性佳，因此灌漿應用於卵礫石層比一般土層灌漿或岩盤灌漿複雜。本文針對卵礫石層雙環塞灌漿之理論依據、施工材料及參數選擇、施工管理重點等進行初步介紹，同時以中壢地區潛盾發進端鏡面灌漿施工案例進行驗證，藉以了解滲透理論及施工參數之適用性，以供日後雙環塞灌漿工法應用於卵礫石層設計與施工之參考。 |
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| Gravel formations comprise compound materials. Their diverse characteristics depending upon content, distribution and nature of the composing gravel and fine-grained materials, together with their high permeability, make it more complicated to apply grouting in gravel formations than in regular soil or rock formations. This paper provides a preliminary introduction to the theoretical background, selection of grout materials and construction parameters, and construction management of sleeve grouting in gravel formations. A case of grouting in a launch shaft of a shield machine in Chung Li area is also studied to verify the applicability of the aforementioned permeation theory and construction parameters. |
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| CASE STUDY ON THE APPLICATION OF HORIZONTAL DOUBLE PACKER METHOD IN CROSSPASSAGE EXCAVATION OF THE TAIPEI MRT |
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| 楊國榮、王錦伍、詹榮鋒、黃敏祥、趙際禮 |
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| CH221、雙環塞、地盤改良、聯絡通道 |
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| 捷運系統聯絡通道開挖期間，常採用高壓噴射灌漿或藥液灌漿等地盤改良工法作為輔助工法。本文介紹藥液灌漿工法中改良成效最佳之雙環塞灌漿工法，使用於台北捷運新店線CH221標聯絡通道開挖時輔助工法之細節，以供工程界未來類似工程設計與施工之參考。 |
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| High pressure or chemical grouting is commonly adopted as an auxiliary method during the excavation of crosspassage of MRT. This paper presents the details of double packer method, the best method of chemical grouting, used as an auxiliary method during the excavation of crosspassage of Contract CH221 of Taipei MRT. This will be a reference for the design and construction of the similar project in the future. |
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| CONSTRUCTION AND GROUND IMPROVEMENT OF A CROSS PASSAGE |
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| 方永壽、林俊次、許仕達、鄭國雄、周黎明、蘇啟鑫、陳滄江 |
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| 壓氣工法、聯絡通道、地盤改良、集水井、潛盾隧道 |
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| 本文藉由台北捷運土城線CD266標工程，介紹潛盾隧道間聯絡通道的地盤改良作業及施工。潛盾機到達前，施工單位即已完成聯絡通道四周土壤的高壓噴射灌漿地盤改良施作。於潛盾機鑽掘通過後，改良體可能受擾動產生裂縫、形成水路，因此於聯絡通道開挖前，必須由主隧道內向外鑽孔，對改良體進行試水作業，以確認地盤改良效果。若試水作業測得的滲水量不符合要求，則由隧道內採低壓方式進行補充藥液灌漿，填充改良體內的水路縫隙。聯絡通道施工採階梯式分段開挖，開挖斷面依序由上而下分為上半部開挖、中間部開挖、下半部開挖與集水井開挖等四個部分。即使開挖區四周的地盤已順利施作高壓噴射灌漿，且改良土體亦已完成試水作業及補充藥液灌漿，但是於施工開挖時，仍可能有地下水滲出，故於開挖過程中，施工單位另採壓氣工法抑制地下水壓，順利完成聯絡通道與集水井的開挖作業。在地表下深處施工遭遇的狀況可能相當複雜，施工人員千萬不能高估高壓噴射灌漿及化學藥液灌漿的止水效果。本文建議，在強大的地下水壓力威脅之下，施工單位宜採取多層防禦的觀念，以謹慎的態度層層戒備，確保施工安全。 |
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| This paper reports the ground improvement and excavation of a cross passage and a drainage sump between two shield tunnels for the construction of Tu-chen Line of Taipei Rapid Transit Systems. Jet grouting was conducted for soils around the cross passage before the tunneling of the shield machine. Leakage tests were conducted to detect the cracks in the JSG soilcrete, and chemical grouting was conducted from the shield tunnel to fill the cracks. Compressed-air method was selected as an auxiliary method to depress the groundwater pressure and prevent water inflow at the face of excavation. The construction of cross passage and drainage sump was successfully completed. It is concluded that the subsurface conditions encountered at a great depth might be quite complicated. The geotechnical engineer should never overestimate the watertight characteristics of the soilcrete body formed around the cross passage by jet grouting and chemical grouting. Under the threat of high water pressure, the contractor is suggested to bear the multiple lines of defense concept to keep the excavation work on the safe side. |
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| APPLICATION OF ELECTRICAL RESISTIVITY IMAGINE PROFILE METHOD IN UNDERGROUND ENGINEERING |
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| 李維峰、張嘉峰、梅興泰、蔡道賜 |
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| 潛盾隧道、地質改良、非破壞性地球物理探測、地電阻影像剖面 |
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| 大地工程中之地下鑽掘工程，如深開挖、捷運潛盾隧道等，皆是一般認定之高風險作業。地質改良效果確認於此類工程為極重要之步驟。一般地質改良均利用破壞性的鑽孔取樣或試水試驗來檢驗地改之成效。但採用鑽孔試水只能代表單點處或是小區域的狀況；並無法清楚明確的得知改良土體的完整性或分佈狀況的情形。針對此一工程問題本文提出一先進非破壞性地球物理探測方法—地電阻影像剖面探測，利用地質改良體或改良土體之高電阻率之特性、以及高含水量軟弱土壤之低電阻率特性；驗證地質改良效果並預測地下工程風險。除說明地電阻影像剖面探測原理與應用外，本文亦提出二個案例，證明此法已由傳統的之地質水文探測，進步到高精度之地下工程實務問題之解決。 |
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| In geotechnical underground engineering, such as deep excavation, shield tunneling construction, is generally considered as a high risk operation. It is very important stage to identify geology improving among these works. In traditional execution, they use destructive method, boring and water test, to verify the effect of geology improving. But they usually present the regional condition only, can not show the whole underground condition. Because of the improving soil or block have high resistivity characteristic and high water content soft soil have low resistivity. In this paper, we use developed non-destructive geophysical exploration, Electrical Resistivity Imagine Profile (RIP), to identify the quality of geology improving and predict the risk in underground engineering. We will introduce two cases and the results show that the RIP can clearly present the condition of underground anomaly. By doing this, we improve this method from 2D to 3D tomography. The outcome shows the traditional geological survey has been improved to a better accuracy in engineering problem solving. |
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| 廖惠菁、李維峰 |
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| 設計例～潛盾隧道聯絡通道地盤改良設計實例 |
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