Xac djnh quan he giu>a thai gian thi cong va chieu sau khoan trong thi cong coc nhoi du'O'ng kinh lan
Time - boring depth relationships of cast-in-place pile construction work
Ngay nhan bai: 20/8/2014 Ngay su^ bai: 5/12/2014 Ngay chap nhan dang: 10/01/201
Le Hoai Long, Nguyin Minh Tam
T O M TAT:
Bai bao da phan chia c6ng tac thi cong coc khoan nh6i thanh hai cong tac chinh la cong tac khoan cgc va cong tac do be tong cpc. De Udc lildng cac thcri gian cua cac cong tac nay, nghien o i u da xay dUng moi quan he giila cac thtfi gian vdi chieu sau khoan bSng cac m o hinh hoi qui d a n bi^n. Cac m o hinh n4y diiOc xem xet v6i 10 dang quan he tuy^n tinh va phi tuyen de liia chon m o hinh tot nhat co phan loai theo diidng kinh coc. Day co the la m^t tai heu hflu ich trong vi?c xac d m h thdi gian thi cong mpt cpc khoan nhoi trong dieu kien thUc te hien nay. Viec xac dinh thdi gian thi c6ng cua m6t coc la ca scr de lap tien dp thi c6ng va dfla ra ke hoach sfl dung nguon tai nguyfen hop ly.
Tfl Khoa: Cpc khoan nhoi, thdi gian thi cong, hoi quy, mo h'mh
ABSTRACT
This paper fragments the process of boring a cast-in-place pile into two main works: drilling work and concreting work.
To estimate durations of these works, this paper develops various relationships between the durations and depth of pile using regression models. The best fit model is selected after considering 10 different types of regression curves. The results of this research are usefiil document for determining duration to complete construction of a pile.
Keyword: Cast-in-place pile, construction duration, regression, model.
TS Li Hoai Long
Khoa Ky thuat Xay Diing, Dai hpc Bach Khoa - D H Q G TPHCM
Dif n thoai: 0977596268 Email: [email protected]
TS N g u y i n Minh Tam
Trfldng Khoa Ky thuat Xay Dflng, Dai hpc Bach Khoa - D H Q G TPHCM
Dien thoai: 0903863348 Email: [email protected]
l . G i d r i t h l | u
Trong nhflng nam gan ddy, khi quy 6it ngdy eang t h u hep, ddt bi^t Id tai cac thdnh p h o Idn nhU Ha Ndi, Tp.Ho Chi Minh thi xu hUdng xdy dflng nhd cao t^ng t r d thdnh tat yeu de dap flng nhu cau xd hdi va phdt t r i ^ kinh te. Tuy thupc vdo tdi trpng cdng trinh, dieu kifen dja chat cung nhU ti'nh kha t h i trong thi cdng, nhd cao tang se co cdc gidi phap nin mdng khae nhau. Trong dd, gidi phap m d n g eoc khoan nhdi Id mdt trong nhflng glai phap nen m d n g pho bien nhat dap flng cac yeu eau ve kT thudt vd kmh te [1,2,71.
Odp iJng dung tien do Id m d t t r o n g nhflng muc tieu hdng dau ddi vdi su thdnh cdng cua mdt d u dn. Vdi vai t r d Id ehu dau tU, viec thiet lap tien dp hdp ly se giup eho nha qudn ly chQ ddng ve thdi gian va chi phi ci^a di/
dn dong thdi la co sd de yeu cau nhd thau cam ket thflc hi^n dung theo ke hoach de ra.Boi vdi nha thau, tien d d Id cd sd de hoaeh dinh nguon tdi nguyen, nhdn luc va dau thau h o p li. Vdi edng tac la thi edng cpc khom nhoi thi can phdi xac dinh dupe t h d i gian thi cdng cua mdt coc [1,4,5A7j.
Trong gidl han cda pham vi nghign cflu, bdi bdo ndy chi xem xit xay dflng md hlnh the hien moi quan he gifla t h d i gian thi edng cpc vd chiSu sau khoan cpc (L) bdng phUdng phap hoi qui don bi4n. Ap dung md hinh tren de udc luong t h d i gian thi edng cpc khoan nhoi.
2. Gifli han cua n g h i e n c f l u
Vl dieu kien thdi gian vd kinh p h i han che nen khdng the nghien cflii...
cho toan b d eae loai hlnh thi cdng c p c Nghien cflu duoc gidi h^n trang pham vi cdng nghe khoan gau xoay trong dung dich Bentonite, Cpc khoan nhoi dUdng kinh t f l 1000mm den ISOOmm.Thu thap so lieu tflh6 Sd nghiem t h u t f l cdc cdng trinh nhd cao tang dTp.HCM. Dfliieu thu t h S p ' t f l 21 edng trinh dan dung, moi edng trinh lay ngau nhien t f l 3 den 5 egc cho moi loai coc cd dUdng kinh vd chieu dai khae nhau. Dfl lieu cpc khoan nhoi ed chieu sdu t f l 40m den 82m vdi chieu sau trung binh la 6 2 5 m .
Thdi gian cdng tac khoan: dupc ti'nh t f l lue t h d i diem bat dau khoan lay dat d gau dau t\in 6irt t h d i diem ket thuc khoan lay dat (T,). ThM gian edng tac bi t o n g eoc: dUoe t i n h t f l thfli d i ^ m vfla kit thOc qua tflnh khoan den t h d i diem ket thijc d o be t d n g cpc (T^.
3. M d h i n h h o i q u y
Md hinh hdi qui don bien dupe d i l n g de xem xet mdi quan he gifla bien phu thude Y va bien dde lap X [3] Bdng 1 liet ke 11 dang md hinh.
Thil tuc Curve Estimation trong SPSS d i i n g xay dung moi quan h | gifia bien Yva bien X theo 11 dang m d hinh khdc nhau.
Mdt sd k i l m ^ n h phdi duoe thuc hien n h u : ktim dinh sU phii hpp cua m d hlnh vd kiem dinh tham sd 14]. Su p h i i h o p eua md hlnh la kiem dinh he so R' cd khac 0 mot each cd y nghla t h d n g ke hay khdng cdn ki^m dinh tham sd nghia la kiem tra xem cac he sd hdi quy c6 ed y nghTa thdng ke hay khdng. Ngodi ra de danh gid m d hinh, sfl dung he sd xdc djnh FP.
ff cang ldn chflng t d m d hinh cdng phu h p p vol dCr lieu. Ciing vdl d d
1 0 0 BnCEnSH 4.2015
Bdng 1: Cde dang dang ducmg hdi quy eua Curve Estimation
1 Linear y = b „ + b , t 2 Logarithmic Y=b(, + b, ln(t)
Bdng 2: Ket qud phdn tich hoi qui T,-L vdi D=1000mm
Parameter Estimates
Quadratic Cubic Power Compound S<urve
Y - b . + b , t + b j t ' Y = b„ + b,t + b,t^ + b3t^
Y = b„t''' Y = b,b;
. 4 ,
Growth Exponential
can xem x^t mfle d d sai sd cda m d hinh, trong bdi bdo ndy Id MAPE. LUa chon md hlnh tdt nh^t bSng cdch so sdnh he sd R= giCfa cdc mo hinh.
4. Ket qu^ phan t i c h
Khi xem xet Idn lUpt mdi quan he gifla T, vi L, mdi quan he glOa T^ vd L, ta xem xit cho loai coc cd dudng kinh D =1000mm, loai coc cd dudng kinh D =1200mm, vd loai coe ed dUdng kinh D >1200mm. Do gidi han chieu dai trang bdon&n ket qud phdn tich chi t i ^ chi duoc trinh bdy eho coc dudng kinh 1000mm. Cpc duflng kinh 1200mm va cpc dUdng kinh Idn hdn 1200mm se chi dUdc trinh bdy kit qud cudi.
4.1 DUdng kinh cgc D= 1000mm Kit qud hdi quy trinh bdy d Bdng 2 vd Bang 3. Xem xet mdi quan hi T,-L, k^t qua eho thay cic md hlnh hfii qui deu ed mfle y nghia Sig.
= 0.000 {<0,05) nen eae md hinh nay phii hop vdl dfl lieu. Ket qud cung cho thay mfle y nghia ciia cdc hi sd hdi qui ddi vfli tSt cd cdc md hinh fleu cd Sig<O.OS, ngoai trflQuadratic va Cubic Id Si9>0.05. Cdc kdt qud ndy cung lap lai vdi mdi quanheT2-L
Ket qud hdi qui T,-L vdl D=1000mm cho thiy tfong tat cd 10 m d hinh hdi qui, md hinh Quadratic vd Cubic cd R^ {R' =0.855) Id idn n h a t tiSp theo Id cae m d hlnh dang Linear va Power.
Inverse ed R^ Id nhd nh5t. Tuy nhi§n, md hlnh Quadratic, Cubic cd kiem d m h y nghia cua he sd h6i quy khdng thda n&n khdng dUoc lua chon Vi v^y, khi xet cpc cd dudng kinh 1000mm, Ifla ehpn md hlnh Linear vd Power Id md hinh tdt nhat cho T,-L (deu cd R' =0.849). Thi/c te cho thiy r^ng khi khoan coe cang sdu thi thdi gian khoan coc cdng lau hon cho mfii met khoan.
Phuong t f l n h mdi quan he T,-L cho thay md Equation Linear Logarithmic Inverse Quadratic Cubic Compound Power S Growth Exponential Logistic
R' .849 .833 .805 .855 .855 .838 .848 .828 .838 .838 .838
F 247.8 218.9 182.1 126.6 1266 237.6 228.0 211.2 227.6 227.6 227.6
d f l 1 1 1 2 2 1 1 1 1 1 1
df2 44 44 44 43 43 44 44 44 44 44 44
Sig.
.000 .000 000 000 .000 .000 .000 .000 .000 .000 .000
Constant -270.05 -2737.7 1397,2 159.29 159.29 123.52 1.532 7.773 4.816 123.52 .008
b l 15.393 831.40
^ 3 2 9 0 . 8 -.607 -.607 1.027 1.474 -77.54 .027 .027 .973
b2
.143 .143
b3
0.000
Bang 3: Ket qua phan tieh hdi qui T^-L vdi D=1000mm
Parameter Estimates
Linear Logarithmic Inverse Quadratic Cubic Compound Power S Growth Exponential
.617 .606 .586 .620 .620 .592 .584 .568 .592 .592
70.88 67.64 62.32 35.01 35 04 63,79 61,80 57,84 63,79 63,79
248 40 -968.09 1069.85 416.08 433,88 351,26 56,341 7.096 5.862 351.26
7.581 409.76 -21338.2 1332 0.000
i.on
.616 -32.153 .011 ,011
.056 .086 ,000
hlnh Power phan anh dung thfle te hon so vdi md hlnh Linear Do vay, khi xet cae epe ed dUcmg kinh 1000mm, lUa chpn md hinh Power la md hlnh tdt nhat cho T,-L
Tuong t u , ket qud hoi qui T,-L vdi D=1000mm cung eho thay md hlnh Linear, Quadratic, Cubic cd R^ (R= =0.620) Id nhflng md hlnh giai thfch tot nhat mdi quan he gifla Tj va L Tuy nhien, md hinh Quadratic, Cubic cd kiem dinh y nghTa ciia he sd hdi quy khdng thda n^n khdng dUoc Ifla chon. NhU vay, khi xet cac cpc cd d u d n g kinh 1000mm, lua chon md hlnh Linear la md hinh tdt nhat cho T,-L
Vdy : De Udc lUpng thfli gian cho edng tac khoan coe T,, nen sfl dung m d hlnh Power vdl phuong trinh: T, = 1,532L'"' (phut) vdi MAPE
=11,27%. Bi udc luong thfli gian cho edng tdc be l o n g eoc T,, sfl dung md hlnh Linear vdi phuong trinh:T^ = 248 + 7.581 L(phiit) vdi MAPE
=8.48%.
4.2 oudng kinh cgc D= 1200mm Xem xet mdi quan he T.-L, tat cd ede md hlnh hdi qui deu cd mfle y nghia cda tdp hop mau Sig=0.000 (<0,05). Mfle -y nghia cda cdc he sd hdi qui doi vdi cac m d hlnh Linear;
Logarithmic; Inverse; Compound; Power; S;
Growth; Exponential, Logistic la Sig<0.05 vd ddi vdi Quadratic va Cubic la Sig>0J)5. Cae ket qud ndy hoan toan tUdng t u cho mdi quan hi T^-L
Ket qud hdi qui T|-L vdi D = l 200mm cho thay trong t^t ca 10 md hinh hdi qui, m d hlnh Compound, Growth vd Exponential cd R^ (R=
=0.769) Ifln nhat, tiep theo Id cdc md hinh Cubic. Md hinh Linear cd R^ =0.729. Cac m d hinh Compound, Growth, Exponential co dang do thj gidng nhau, ta cd the Ifla chpn m d t trong 3 m d hlnh de d u b a o .
Ket qud hdi qui T^-L vdi D=1200m eho thay trong tat cd 10 m d hinh hdi q u i , m d hlnh dang Power ed R' (R= =0.498) la Icm n h a t tiep theo
4.2015BnGIE[|Bl i
Id cdc m o hlnh dang Compound, Growth va Exponential. M d hlnh Linear cd t r i sd R^ ^ . 4 8 4 , khdng chenh nhieu so vert tri sd R^ ciia Power.
Vay : Bi Udc lUpng thc^ gian cho cdng tac khoan coc T,, n^n sfl d u n g m d hinh Compound vdl phuong trinh : T , = 173.4 x 1.023"^ (phut) vfli MAPE=8 J 4 % . De Udc lUpng t h d i gian cho cdng tac be t d n g coc T^, sfl d u n g m d hinh Unear vdi phuong t r i n h : T^ = - 325.4 -1- 7.126'- (phut) vdl MAPE=6.14%.
43Biidngkinhcgctit1200mmdat1500mm Ket qua eho thay t a t ea eae m d hinh trong nhdm dUdng ldnh cpc nay cung cd ciing ket qua n h u 2 nhom dudng kinh trudc.
Ket qud hdi qui T,-L vdi D >1200mm cho thay trong tat ca 10 m d hlnh hdi qui, m d hlnh Compound, Growth va Exponential cd R' fjP
=0.709) Idn n h a t t i ^ p theo la cac m d hinh Cubic. M d hinh Linearcd R= =0.729. Cac m d hinh Compound, Growth, Exponential ed dang d o thi gidng nhau, ta ed the lUa chon m d t trong 3 m d hinh de d f l bao. NhU vay, khi xet epe cd dUdng kinh > 1200mm, lUa chpn m d hinh Compound la m d hlnh t d t nhat eho T1-L
Ket qua hdi qui T^-L vdi D >1200mm d i o thay m d hlnh Power va S-eurve cd R' = 0 5 9 6 la Idn nhat. M d hinh Linear cd t r i sd R' = 0 5 6 8 , khdng chenh nhieu so vdi trj sd R' ciia Power.
N h u vay, khi xet cpc cd d U ^ g kinh Idn hon 1200mm, Ifla ehpn m d hinh Linear Id m o hinh t d t n h S t e h o T ^ - L
Vdy : Bi udc lupng t h d i gian cho cdng tac khoan cpcT,, n^n s f l d u n g mo hlnh Compound vdi phuong trinh :T, = 273.9 x 1.01 ff- (phut) vdi MAPE=6,81 %.Oe Uflc lUOTg t h d i gian eho cdng tac be t d n g coe T2, sfl dung m d hlnh Linear vdi phUOTig trinh: T, = 352 + 7.220^ (phut) vdi MAPE-4.77%.
5. Ket luan
Nghien eflu da xdy dung dupe mdi quan he giOa thcrt gian cdng tde khoan cpc vdi chieu sau coc (T,-L) va m d i quan hi giCia t h f l i gian cdng tdc be tong coc vfli chieu sau cpc (T^-L) bang edc m d hinh hdi qui. Cd tat ca 10 m d hinh cho mdi quan he T|-L va 10 m d hinh cho mdi quan he T j - L DUa vao ket qua m d hinh hoi qui la cdc phuong trlnhTj-LvaT^-L, c d t h e udc lugng dupc thdi gian eae edng tac khoan vd edng tac be t d n g coc theo chieu sau epe L
M d hinh T,-L cd ket qua rat t d t md hinh Tj-L eung cd ket qua tUong d d i t d t Tuy nhien m d hinh T,-L cho ket qud t d t hOn m d hinh T^-L la p h u hop thuc t e vl qud trinh khoan la m d t qua trinh lien tue t f l Iiie bat dau khoan den lue ket thiie khoan, trong khi d d qud trinh trien khai cdng tdc be tdng lai t)ao g d m nhieu cong tdc n h u ve smh h d khoan, Idp dflng Idng thep, lap dng do, d o b^ t d n g va m d t sd cdng tac p h u khac, d o d d ma qua trinh ndy khdng lien t u c vd t h u d n g xuyen bi gian doan.
Ket qua cung chi ra rang ede m d hinh T,-L t d t nhat deu cho thay khi chieu sau khoan cang
Idn t h i t h d i gian se tang len rat nhanh. Dieu ndy p h i i h < ^ vert thflc te vl khi khoan eang sau t h i thao tac t h i edng cdng k h d thUc hien, can khoan se b i gidm yeu nen edng suat lay d a t cung gidm, h o n n u ^ duflng di c h u y i n cda gau khoan cang tang vi vay ma thdi gian khoan se tang l^n.
TAI UEU THAM KHAO
[1] Nguyen \n^t Tning, Ntia xuat ban xay dung' Coc khoan nhoi trong cong tflnh giao thong'
[2] te Ngoc Hien, "Xac dinh nang suat noi bo tien trinh thi cong CDC khoan nhoi' LVTS 2D08, nganh Cong nghe va quan ly ray dimg. f)H8K.
[3] Long Le-Hoai va Young Dai Lee, 2009, 'Time-cost relationships of bmlding constmctiDn project m Korea' Fadlities ffffierald group) VDU7,Na13/14
[4] Zayed. T. M. (2001). "Assessmetit of productivity for conoete bored pile conitnicfion.' PhD thesis, School of Ovil Engme«ing. Puitlue Univ., West La^yette, Ind
[5] Zayed, T M, va Halpin, D. W. (2004). Tiocess versus data onenled techniques in pile construction productivity assessment'!. Constr. Eng. Manage., 130-4!, 490-499.
[6] Zayed, m. and Halpin, D.W. (2004a) Quantitative assessmenlforpilespmductivity factors Joumal of Constiuction Engineenng and Management, ASCE, 130(3).40S-14.
[71 Tomlinson, MJ. 'File Design and Construction Practice"
E&FN Spon Publitation, London. 1994,4lh Edition
102^raiEilQS 4.2015
