update孟加拉OCell法樁基靜載試驗(yàn)方案提交

1、government of the peoples republic of bangladeshoffice of the project directorpaira bridge (lebukhali bridge) construction projectroads and highways departmentroad transport and highway divisionministry of road transport and bridgesconstruction of 1470 meter long paira bridge (lebukhali bridge) over

2、 the river paira including approach road, bank protective and related work atth km barisal-patuakhli road(n-8)paira bridge (lebukhali bridge) loading test project of the piles試樁靜載試驗(yàn)實(shí)施方案中國(guó)北京建筑大學(xué) 北京市城市交通基礎(chǔ)設(shè)施建設(shè)工程技術(shù)研究中心中國(guó)黑龍江路橋一公司beijing urban transportation infrastructure engineering technology research

3、 centerbucea, beijing chinano. 1st branch of heilongjiang road and bridge co., ltd., haerbin china2016-02-21paira bridge (lebukhali bridge) construction project-loading test project of the piles試樁靜載試驗(yàn)實(shí)施方案目錄1工程概況/engineering background31.1橋梁概況/bridge configuration31.2試樁概況/ outlines of the testing pil

4、es32試驗(yàn)依據(jù)及要求/test basis and requirements62.1試驗(yàn)依據(jù)/test basis62.2試驗(yàn)要求/test requirements63試驗(yàn)原理/ test principles74實(shí)施方案/test project114.1試樁位置/ the location of testing piles114.2荷載箱的選擇/ the choice of loading cells124.3測(cè)試儀器安裝/ installation of test instruments144.3.1荷載箱和連接的壓力管線/load box and its connected pre

5、ssure pipeline144.3.2振弦式位移傳感器/vibrating displacement sensor154.3.3應(yīng)變桿/strain bars154.4.4振弦式應(yīng)變計(jì)/ vibrating strain extensometer154.3.5塑料管/plastic pipe154.3.6動(dòng)力組件/power components154.3.7安裝基準(zhǔn)梁及數(shù)據(jù)采集系統(tǒng)/the installation of reference beam & data collectionsystem164.4試樁進(jìn)度安排/ testing schedulre174.5現(xiàn)場(chǎng)測(cè)試/field

6、test174.5.1端部承載力試驗(yàn)（3.5m試樁) /bearing capacity test of pile end (for 3.5m test piles)174.5.2總承載力和分層側(cè)壁摩擦力試驗(yàn)（3.5m試樁) /total bearing capacity test & layered sidewall friction for 3.5m test piles194.5.3總承載力和分層側(cè)壁摩擦力試驗(yàn)（其它試樁)/test of total bearing capacity and layered sidewall friction test (for other test p

7、iles)204.6結(jié)果分析/analysis of test results204.7報(bào)告內(nèi)容/report contents205需要業(yè)主和施工方提供的協(xié)助/ needed assistance provided by owners and constructors 216驗(yàn)證荷載數(shù)量及觀測(cè)耗材預(yù)估/estimation list of proof load and observation materials237附件/attachments257.1 o-c安裝試驗(yàn)過程/ the process of o-cell installation test l257.2 囊式荷載箱安裝試驗(yàn)過程

8、/installation and test procedure of capsule-type load cell267.3 國(guó)產(chǎn)設(shè)備及試驗(yàn)性能簡(jiǎn)介/introduction to the domestic equipment and its test performance277.4 相關(guān)業(yè)績(jī)簡(jiǎn)介/introduction to our relevant achievements281工程概況/engineering background1.1橋梁概況/bridge configurationbridge configurations as based on the employers r

9、equirement have been summarized below. outline configurations for main bridge and extra-dosed type of super structure maintaining minimum span requirement by the consultants. 需要中文原文？ the height of tower will be within the limit set by the civil aviation authority for the flight path.1) 橋梁長(zhǎng)度/length o

10、f the paira bridge主橋/main bridge：630m(115m+2200m+115m)引橋(高架橋)/bridge with viaduct：840m主跨/main span：200m2) 橋面布置/bridge deck行車道寬/carriage way width：27.3m人行道寬(含路緣石) width offootpath with kerb：21.10m (minimum)防撞墻寬/ width of bump wall：0.305m (minimum)中間帶寬width ofcentral barrier：2.96(minimum)上部結(jié)構(gòu)類型/types

11、of superstructure：pre-stressed concrete extra-dosed box-girder 3) 結(jié)構(gòu)類型/types of structure上部結(jié)構(gòu)類型/types of superstructure：預(yù)應(yīng)力箱梁、預(yù)應(yīng)力混凝土斜拉橋箱梁/pre-stressed concrete box-girder, pre-stressed concrete extra-dosed box-girder 下部結(jié)構(gòu)類型/types of substructure：鋼筋混凝土（橋臺(tái))、實(shí)體墩、豎井、箱型墩塔/rcc abutments, reinforced concre

12、te solid piers, shafts, box-type piers /pylon4)基礎(chǔ)類型/ types of foundation:斜拉橋主墩的基礎(chǔ)/foundation of the main extra-dosed span.5m鋼筋混凝土圓形樁/rcc solid circular pile with 3.5m diameter引橋的墩臺(tái)基礎(chǔ)為/ the pier foundation of approach span2.5m/1.5m鋼筋混凝土圓形樁/rcc solid circular pile for viaduct support span with 2.5 m/1

13、.5 m diameter 1.2試樁概況/ outlines of the testing piles工程師指定在主橋橋墩p16, p17, p18,p19和p20位置選擇工作樁或制作試樁進(jìn)行奧斯托堡法加載試驗(yàn)。p16和p20橋墩樁基直徑為2.5m，初步設(shè)計(jì)樁長(zhǎng)110m；p17, p18和p19墩塔樁基直徑為3.5m，初步設(shè)計(jì)樁長(zhǎng)130m。初始試驗(yàn)在試樁上進(jìn)行，試樁驗(yàn)證荷載不超過設(shè)計(jì)荷載的250%。然后在工作樁上進(jìn)行加載試驗(yàn)，工作樁驗(yàn)證荷載規(guī)范沒有規(guī)定，但是根據(jù)規(guī)范中工作樁作為反力樁的要求，應(yīng)控制樁頂位移不超過0.5mm。the osterberg load test will be tak

14、en at the main bridge drawings p16, p17, p18, p19, and p20, which will be specified by project engineers either through working piles or building test piles. the diameter of bridge pile foundation on p16 and p20 is 2.5m, and the preliminary design of its pile length is 110m. the diameter of bridge p

15、ile foundation on p18 and p19 is 3.5m, and the preliminary design of its pile length is 130m.the initial test will be carried out on test piles, whose verification load should not exceed 250% of the designed load. then the loading test will be carried out on working piles, whose top displacements sh

16、ould not exceed 0.5mm based on the requirements of working piles as counterforce one in the code requirements, though it is not regulated in the verification load code.圖1-1 主橋立面圖 /fig.1-1 elevation of the main bridge表1-1 試樁工程數(shù)量表/table 1-1 quantities of pilot test pileso-cell tests (osterberg cells)

17、to be carried out at pile locationp16, p17, p18, p19 and p20 as directed by the engineer.單位/unit數(shù)量/numfor 2.5m dia cast-in-situ rcc piles-design vertical load 50mn.-i) initial pile load test on pilot/non-working pile(including cost of pilot pile). load test vertical load 125mn.(250%)nos.1ii) routine

18、 pile load test on working piles. load test vertical load 75mn.(150%)nos.2for 3.5m dia cast-in-situ rcc piles-design vertical load 110mn.-i) initial pile load test on pilot/non-working pile ( includingcost of pilot pile). load test vertical load 275mn.nos.1ii) routine pile load test on working piles

19、. load test vertical load 165mn.(150%)nos.32試驗(yàn)依據(jù)及要求/test basis and requirements2.1試驗(yàn)依據(jù)/test basis1 paira bridge construction project tender documents: technical specification.2 the aashto lrfd bridge specification (3rdedition,2004).3 the aashto bridge design specification (6thedition,2012).4 astm d1

20、143-07：standard test methods for deep foundations under static axial compressive load.5 optimum loading specifications for o-cell bi-directional static load testing.6 theindustry standard of the peoples republic of china: pile static load test with self-balancing method (jt/t 738-2009).2.2試驗(yàn)要求/test

21、requirements1)試樁制作/the preparation of pilot test pile測(cè)試樁應(yīng)選擇與工作樁相似水文地質(zhì)環(huán)境、采用相同設(shè)備和材料進(jìn)行施工。試樁成孔的尺寸、形狀位置必須合乎設(shè)計(jì)要求，需進(jìn)行成孔質(zhì)量檢測(cè)。each pilot test pile shall be constructed in a manner with similar hydrogeological environment that to be used for the construction of the working piles, and by the use of similar equ

22、ipment and materials. the hole size, the pile shape and the position shall follow the design requirements, and the quality detection of the holes should be required. any variation shall only be permitted with prior approval.2)加載設(shè)備/ loading equipments根據(jù)試樁樁徑、預(yù)估極限承載力大小的具體要求，可選用單個(gè)荷載箱，也可以多個(gè)并聯(lián)布置；為了滿足特定的要求

23、，荷載箱可以單層布置，也可以多層布置。每個(gè)荷載箱在使用前均經(jīng)過授權(quán)計(jì)量單位進(jìn)行壓力荷載的標(biāo)定。選用的荷載箱直徑應(yīng)小于樁徑，荷載箱一般焊接在主筋上。加載設(shè)備應(yīng)控制在1.5倍的工作壓力下不破壞。a single load cell or multiple ones with parallel arrangement can be chosen according to specific requirements of pilot test pile diameter and its estimated ultimate bearing force. in order to meet the spe

24、cific requirements, the loading cells can be arranged in single layer or multiple layers. calibrations load and pressure for each load cell beore use must be calibrated by authorized measurement department.the diameter of the load cell should be less than the diameter of the pile, and it is generall

25、y soldered to the main steel bar. the loading equipment should be controlled without damage at 1.5 times of the working pressure.the hydraulic jack, pump, hoses, pipes, couplings and other apparatus to be operated under hydraulic pressure shall be capable of withstanding a test pressure of 1.5 times

26、 the maximum working pressure without leaking.缺中文原文 3)注漿/grouting工作樁試驗(yàn)完成后，通過預(yù)留的注漿管（直徑25mm)對(duì)試驗(yàn)過程中由荷載箱工作形成的樁身開裂空間進(jìn)行注漿，以作永久性封閉。after the work of pile test is finished, the pile cracking space formed by the working of load cell must be grouted through the reserved grouting pipe whose diameter is 25mm so

27、 as to keeping permanent closure.3試驗(yàn)原理/ test principles1)奧斯托堡法the osterberg load test methodosterberg cell load test（簡(jiǎn)稱為o-cell試驗(yàn) )，是由美國(guó)西北大學(xué)prof. osterberg于1991年創(chuàng)導(dǎo)的一種獨(dú)特的樁基荷載試驗(yàn)方法，簡(jiǎn)稱奧氏法。其利用樁的自重、樁周土的摩擦力與樁端土阻力作為一對(duì)反力的基本原理，借助埋設(shè)于樁身（底)的壓力盒向上、向下同時(shí)施加荷載，以獨(dú)立地獲取樁側(cè)阻力位移曲線及樁底阻力位移曲線。奧氏法的核心設(shè)備是稱為o-cell（國(guó)內(nèi)通常稱之為荷載箱或壓力盒)的

28、大噸位液壓千斤頂。試驗(yàn)時(shí)通過樁頂液壓管路向 o-cell加載，o-cell向下的作用力由樁端承載力平衡，向上的作用力由樁身的側(cè)摩擦力平衡。一般將o-cell放置在樁底的底部，形象地稱為樁底加載法。經(jīng)過二十多年的不斷探索改進(jìn)，現(xiàn)在o-cell除了放置于樁的底部外，還可以放置在樁身不同中的不同部位，也可以在同一根樁內(nèi)放置若干的o-cell。常規(guī)樁頂加載試驗(yàn)的樁頂荷載p等于樁側(cè)摩阻力f和樁端阻力q之和，即p=f+q，不計(jì)試樁前樁身自重w在樁端的反力。奧氏法試樁時(shí)通常采用荷載箱在樁底部產(chǎn)生向上、向下二個(gè)方向的荷載p0，向上的荷載p0=w+f，向下的荷載與樁端的樁身自重反力及由加載產(chǎn)生的端部反力增量q之

29、和平衡，即p0=w+q，受力機(jī)理和樁頂加載相同。于是該二種試樁方法的荷載換算如下：p=f+q=（p0 -w)+（p0 -w)=2 p0 -2w （其中o-cell加載量p0 =液壓表讀數(shù)標(biāo)定常數(shù))。osterberg cell load test, i.e. o-cell test, is a unique method of pile load test method created and guided by prof. j. osterberg at northwestern university in 1991. based on the balance principle of a

30、pair of counter forces between the pile weight and the counter directional forces including soil friction force around pile and resistance force at the bottom end, such curves as between resistance around a pile and displacement, and between resistance at the bottom end and displacement, will be obt

31、ained respectively, while the loads are applied from the upward and the downward simultaneously by means of the pressure cells which are located at the middle pile or at the pile bottom.the key equipment of the o-cell method, which is commonly referred to as load cell or pressure cell in china, is a

32、 large tonnage hydraulic jack. when the o-cell load test pile is carrying out, the load to o-cell is applied by hydraulic pipeline at the pile top, and here the downward force of o-cell is balanced by bearing capacity at the end of the pile and the upward force is balanced by the friction force arou

33、nd pile. while the o-cell is placed at the bottom of the pile, it is vividly called loading method of pile bottom. after 20 years of continuous exploration and improvements, the o-cell can not only be placed at the bottom of the pile, but also be placed at different parts of the pile, and many o-cel

34、ls can be placed in a pile.the pile load p of conventional pile load test equals the friction around a pile f and the resistance at the bottom of a pile q, that is p = f + q, without including the reaction produced by the self weight w of a pile at the end before testing. when o-cell method is used

35、in working pile, usually load p0 is produced by load cells in two directions (upward and downward) at the bottom of the tank. the upward load p0=w+f and the downward load is balanced by the weight of the pile and the reaction force increment at end of a pile q due to being generated by loading, that

36、 is p0 =w+q. the mechanism is same to loading at the top of a pile. so the load conversion of these two test methods is as follows: p=f+q = (p0-w)+(p0 -w)=2p0-2w (1)where o-cell loading =manometer readings calibration constant.圖3-1 奧氏測(cè)樁法與傳統(tǒng)靜載方法原理對(duì)比fig.3-1 o-cell pile test method and the traditional

37、principle of comparative static load圖3-2 奧氏測(cè)樁法fig.3-2 the osterberg load test method圖3-3 奧氏測(cè)樁法實(shí)測(cè)荷載位移曲線示例fig.3-3 the curve sample of the o-cell test pile method measured load displacement 圖3-4 奧氏測(cè)樁法等效樁頂加載法荷載沉降曲線示例fig.3-4 the curve sample of o-cell test pile method of equivalent pile load-settlement t

38、op loading method2)自平衡法/self-balanced method奧氏法在國(guó)內(nèi)被業(yè)界稱為自平衡法，自九十年代后期由美國(guó)引入中國(guó)，先后有一些國(guó)內(nèi)工程采用自制的o-cell進(jìn)行試樁。自平衡法即利用上段樁側(cè)阻力和下段樁側(cè)阻力與端阻的自相平衡的一種測(cè)樁法。樁身某一位置，其上段樁身自重及樁側(cè)極限摩阻力之和與下段樁樁側(cè)極限摩阻力及極限樁端阻力之和基本相等，即為平衡點(diǎn)。近幾年來，國(guó)內(nèi)研制成功和迅速推廣普及的專業(yè)荷載箱（如腔式荷載箱、囊式荷載箱)，在提高樁基安全性、試驗(yàn)成功率、試驗(yàn)安全性、試驗(yàn)準(zhǔn)確性的同時(shí)，降低了檢測(cè)項(xiàng)目成本，對(duì)自平衡測(cè)樁法的發(fā)展和完善提供了強(qiáng)有力的支持。the o-ce

39、ll was called self-balanced method in chinese domestic industry, introduced from the united states since 1990s, some of the domestic engineering project in china have used homemade o-cell to test pile. self-balanced method is to use resistance from the top period of the pile and the resistance from

40、the descend period of the pile to reach equilibrium. the balance point is a particular location of pile, its weight of top pile and the sum of its frictional resistance of pile side in the upper limit was equal to the sum of the descend period of pile side friction and the pile tip resistance limit.

41、in recent years, with the successful development and rapid popularization of domestic professional load cases (such as cavity load cases, bladder type load box), the safety of the pile foundation, test success rate, test security, and test accuracy is increasing at the same time, the detection of th

42、e project cost is reducing, which provided a strong support for the development and perfection of the self-balanceding test method.圖3-5 自平衡法測(cè)樁原理fig.3-5 a sketch of the self-balance pile test4實(shí)施方案/test project4.1試樁位置/ the location of testing piles工程師指定在主橋橋墩p16, p17, p18,p19和p20位置選擇工作樁或制作試樁進(jìn)行奧斯托堡法加載試驗(yàn)

43、。specific locations will be chosen at main bridge pier p16, p17, p18, p19, and p20 by project engineers, where osterberg load test will be taken through working piles or making test piles.4.2荷載箱的選擇/ the choice of loading cells合格的荷載箱，是測(cè)樁成功的必要條件，但絕不是充分條件。低品質(zhì)的荷載箱產(chǎn)品，主要表現(xiàn)在加載失敗率較高或者加載（線性)性能超差，這將直接影響樁基加載試驗(yàn)

44、的成功率，以及試驗(yàn)數(shù)據(jù)的真實(shí)性和準(zhǔn)確性。qualified load cell is a necessary condition of success, but is not a sufficient condition. load case of low quality products, mainly displays its failure rate in the loading is higher or load (linear) performance is poor, which will directly affect the success rate of pile load

45、test, and the authenticity and accuracy of test data.1)o-cell荷載箱/o-cell load cases采用奧斯托堡的專利產(chǎn)品o-cell。根據(jù)本工程特點(diǎn)，選用的cell數(shù)量及主要參數(shù)應(yīng)滿足表4-1之要求。using the patented product o cell，according to the engineering features, cell number and main parameters should satisfy the requirements of table 4-1.表4-1試驗(yàn)選用o-cell主要指

46、標(biāo)table 4-1 main parameters in test for using o - cell 試樁/ test pile荷載箱/ load cells樁類別/category of pile驗(yàn)證荷載/proof load樁數(shù)量/the numberof pileo-cell數(shù)量/the number of o-cell 直徑/diameter最大行程/maximum stroke極限加載量/limit load3.5m試樁/ test pile275 mn14660mm150mm32mn*4*34660mm150mm3.5m工作樁/working pile165 mn34660m

47、m150mm32mn*4*22.5m試樁/ test pile125 mn13660mm150mm32mn*3*22.5m工作樁/working pile75 mn23660mm150mm32mn*3*2圖3-6 o-cell 平面布置 fig.3-6 layout of o-cell2)囊式荷載箱/load cases of capsule type采用國(guó)內(nèi)自制的囊式荷載箱。根據(jù)本工程特點(diǎn)，選用的荷載箱數(shù)量及主要參數(shù)應(yīng)滿足表4-2之要求。using the domestic capsule type load cases. according to the engineering featu

48、res,the number of load cases and main parameters shall meet the requirements of table 4-2.表4-2試驗(yàn)選用囊式荷載箱主要指標(biāo)table 4-2 main parameters in test using for capsule-type load cells試樁/ test pile荷載箱/load cells樁類別/category of pile驗(yàn)證荷載/proof load樁數(shù)量/the pile number囊式荷載箱數(shù)量/the capsule type load cases number直徑/

49、diameter最大行程/maximum stroke極限加載量/limit load3.5m試樁/ 3.5m test pile275 mn18650mm200mm15mn*8*38650mm200mm3.5m工作樁/3.5m working pile165 mn38650mm200mm15mn*8*22.5m試樁/ 2.5m test pile125 mn16650mm200mm15mn*6*22.5m工作樁/2.5m working pile75 mn26650mm200mm15mn*6*2圖3-6 囊式荷載箱平面布置/ fig.3-6 the layout of capsule typ

50、e load cases 4.3測(cè)試儀器安裝/ installation of test instruments測(cè)試儀器包括荷載箱及其連接的壓力管線、振弦式位移傳感器、應(yīng)變桿和振弦式應(yīng)變計(jì)等組成。testing instrument should include load cells，its connected pressure pipeline, vibrating wire displacement sensors，strain rod and vibration chord strain gauge, etc.4.3.1荷載箱和連接的壓力管線/load box and its conne

51、cted pressure pipeline1) 根據(jù)3.5m試樁的基本要求和提供的該樁設(shè)計(jì)極限承載力，采用2層荷載箱的方法來分別測(cè)試樁側(cè)摩阻力和樁端極限承載力。荷載箱放置在樁中性點(diǎn)和樁底1.5m處。每層荷載箱串聯(lián)。荷載箱進(jìn)、出水口分別通過壓力管線連接到測(cè)試平臺(tái)。測(cè)試時(shí)，壓力管線兩端分別連接壓力傳感器和空氣壓縮機(jī)驅(qū)動(dòng)的水泵，空氣壓縮機(jī)提供動(dòng)力水泵產(chǎn)生壓力水，使荷載箱產(chǎn)生向上和向下的推力，壓力傳感器顯示荷載箱內(nèi)壓力，即其產(chǎn)生的向上和向下的推力。2) 其余試樁和工作樁測(cè)試采用單層荷載箱，根據(jù)樁周的土質(zhì)狀況和樁的類別，確定荷載箱位置。1) according to the basic require

52、ments of 3.5 m test pile and the pile ultimate bearing capacity design, we adopt the method of 2-layer load cases to respectively test the limit bearing capacity of pile side friction and pile end. load box will be placed in a neutral point of pile and pile bottom of 1.5 m. each layer load box serie

53、s. through pressure pipeline the inlet and outlet of load cases are connected to the test platform respectively. in the testing, both ends of pressure pipeline will connect pressure sensor and air compressor driven pump respectively, the air compressorwill powe pump pressure water, so that the load

54、box can generate upward and downward thrust and the pressure sensor indicates the pressure inside the load i.e. the upward and downward thrust.2) the rest test of testing piles and working piles will use single load box, the position of the load box will be determined by the soil condition and types

55、 of the pile. 4.3.2振弦式位移傳感器/vibrating displacement sensor在每層荷載箱上、下支撐鋼板之間各安裝4支基康（geokon,usa)4450型振弦式位移傳感器，在測(cè)試期間測(cè)量荷載箱的張開量。另外，安裝有3組振弦式位移傳感器（每組2支)，分別測(cè)量埋入到樁身內(nèi)壓縮應(yīng)變桿的位移量。on each load case, between the upper support buttress plate and the lower support buttress, we will install four geokon (geokon, usa) 445

56、0-type vibrating wire displacement sensors, measuring the open test volume of load box during texting. in addition, it will be equipped with three vibrating wire displacement sensor group (n=2), to measure the amount of displacement buried within the pile compressive strain rod respectively.4.3.3應(yīng)變桿

57、/strain bars整個(gè)樁身內(nèi)部安裝3組埋入式壓縮應(yīng)變桿，測(cè)試期間分別監(jiān)測(cè)整個(gè)樁身的變形量。the whole internal pile body will install 3 groups of embedded compression stem strain , respectively monitoring the amount of deformation during the test throughout the pile.4.4.4振弦式應(yīng)變計(jì)/ vibrating strain extensometer根據(jù)試樁參考地質(zhì)鉆孔資料，在主要土層分界面安裝振弦應(yīng)變計(jì)，在承載力測(cè)試期間，通過讀取應(yīng)變計(jì)的讀數(shù)來測(cè)量樁對(duì)各主要土層的摩擦力。according to the reference of test pile geological drilling data, vibrating wire strain gage should be installed in