KHOA HOC - CONG N G H I
Tap chi GTVT 7/2009
NGHIEN Cdu GIAI PHAP flIEU KHIEN Tlf BONG THIET Bj THI CONG COC XI M A N G BAT
THEO CONG NGHE TRON KHO PHUC VU GIA CO NEN DAT YEU Of VIET NAM
TS. NGUYEN XUAN KHANG Vien Khoa hgc vi Cdng nghe GTVT
Tdm tit: Td ddng hda qua trinh hoat ddng cua thiet bi thi cdng la khuynh hddng phat trien hien nay cua nganh cdng nghiep che tao may tren the gidi ndi ehung va thiet bi thi cdng eoc xi mang dat (CXMD) ndi rieng.
Day chuyen thiet bl thi cdng CXMD la td hap gdm may ca sd. thiet bi khoan, thiet bi cap xi mang rbi, he dinh Idang phun xi mang va he dieu khien. Cac thiet bi trong day chuyen thi cdng CXMD dudc dieu khien td ddng ky thuat sd mang lai nhieu du diem trang van hanh. nang caa nang suit, giam suat tieu haa nang ludng. hien thi cae thdng sd ed bin eua qua trinh cdng nghe... nhat la dim bia do ddng deu cua hdn hdp vat lieu tren toan bd the tich cua CXMD va nang eao chat Idpng thi cdng CXMD.
Bai bao trinh bay cac giii phap dieu khien td ddng diy chuyen thiet bi thi cdng CXMD dap dng dddc cie quy trinh thi cdng hien hanh nhim dat hieu qui caa nnat.
Abstract: Full automation of equypment is a papular trend of the machinery manufacturing industry in gen- eral, and equypment far construction of sail concrete pile specifically. Production line far construction work of sail concrete piles consists of basic machine, dniling machine, separate cement-pouring equypment. cement dosing pump system, and central system. Items of equypment in the production line with automatic control system have advantages in operation, increasing productivity, decreasing power consumption, displaying parameters of the process etc... and especially ensuhng the uniformity of aggregates all aver soil concrete pile and improving the quality of the eonstructian work.
This article deals with solution to automatic control af production line for eonstructian of sail concrete pile to meet current requyrements in order ta have the best quality.
1. Dat van de
Khi xay dyng cdng trinh tren n I n d i t y i u c l n phai tien hinh gia ed n I n mdng. Tyy loai cdng trinh, dia chat n I n mdng v i c i e yeu e l u cy the m i ngydi ta sd dung cae cdng nghe gia ed khie nhau. Gia cd nen d i t y i u b i n g cdng nghe trdn s i u CXMD la phuong phap cai tao dat dyng eho dat set deo, byn set, d i t l l n hdu CO, dat lan bun, cat chiy,... Viee trdn hon hpp d i t - xi mang theo chieu sau tdi da tdi 25m l i m tang eUdng dp, dp chat, tang md duyn dan hdi ciia nen dat.
Cudng dp dupe hinh thanh ngay sau khi gia ed va phat trien theo thdi gian. Phuong p h i p nay dung ehii yeu de ngin c h i n , g i i m dp lyn eung nhu tang he sd an toin cho cae cdng trinh n I n dUdng, dudng dap, dUdng xe Ida... c i c cdng trinh mdng nha dan dyng cdng nghiep vda va nhd, n I n mdng c i e b i n cang, bai dd xe, s i n bay... dem lai hieu q u i kinh te - ky thuat.
Theo cae phUOng p h i p thi cdng khie nhau ed the chia thinh hai loai trdn khd va trdn udt. De thi cdng c i c CXMD theo cdng nghe trdn khd, c l n p h i i sd dyng he thdng thilt bi chuyen dung. 6 c i e nUde ed nginh cdng nghiep che tao may p h i t t r i l n , cae thilt bi n i y da dupe che tao vdi eae tinh nang ky thuat hien dai. t o i n bd d i y chuyen thilt b| dUPe d i l u khiln ty ddng theo chyong trinh v i sd dyng rdng r i i trong thi cdng.. G i i nhap khIu day chuyen thilt bi nay tdi hon chyc ty VND Trong khi dd h l u h i t c i c thiet bi thi cdng CXMD d nude ta hien nay l i n h i p k h i u td Trung Qudc vdi he djnh Iddng v i phun xi mang dieu khiln chii yeu b i n g tay, vi vay nang s u i t thi cdng khdng cao v i c h i t lUpng khdng dn djnh.
Theo ket qua nghien cdu [1], chung ta cd the sd dyng nhung thiet bi s i n cd trong nudc nhu may eO sd, thilt bi cap xi mang rdi, nhap thiet bi khoan ddng thdi c h i tao trong nude he dinh lupng phun xi mang v i he dieu khien la cd d i p c day chuyen thiet bi thi cdng CXMD theo cdng nghe trdn khd vdi tinh nang ky thuat t i l n t i l n ed t h i thay t h i nhap ngoai- Trong bai b i o nay t i e gia ehi de cap tdi c i e giai phap dieu khiln ty dpng day chuyen thiet bj thi cdng CXMD.
He d i l u khien tU ddng ed nhiem vu d i l u khiln c i e thao t i c ciia toan bd day chuyen thilt bj thi cdng:
- Khoan cdt d i t , kiem soit chilu sau khoan; rut mui khoan. giam s i t tdc dp riit mui khoan va trdn deu hdn hpp xi mang dat.
- Dinh lupng xi mang, k i l m soat trpng lUpng xi mang da phun vao dat n I n trong sudt q u i trinh thi cdng.
- Dieu chinh tdc dp phan phdi xi mang de thay doi trpng lUpng xi mang dUpc phun vao dat n I n nham dam bao dp ddng deu ciia hdn hpp xi mang d i t trong toan bp the tich CXMD.
- Dieu khiln he nen khi gdm hai he: he truyen ddng ddng md cac van va he cdng t i c : "hoa Idng xi mang"
tao thanh hdn hop khi xi mang ed dp linh dpng phu hpp v i phun xi m i n g .
- D i l u khien toan bd c i e thiet bi trong day chuyen thiet bi thi cdng CXMD hoat ddng theo dung trinh ty phu hop vdi quy trinh thi cdng hien hanh mdt each tu ddng theo cac chdOng trinh da dupc cai dat san. C i e chuong trinh dUpc x i y dyng d dang md d l ed t h i thay ddi nhdng thdng sd cO ban theo yeu cau ciia tdng
11
KHOA HOC - C O N G NGHE cdng trinh ey the.- H i l n thj cae thdng sd eO ban eiia q u i trinh thi cdng, lUu giO cac k i t q u i , phdng ngda c i c sU cd v i in c i c k i t q u i thi cdng theo tdng cpc.
C h i tao he d i l u khiln ty ddng d i y c h u y i n t h i l t bj thi cdng CXMD la mdt trong nhdng van de quan trpng trong viee c h i tao t h i l t bi thi cdng CXMD d Viet Nam.
Nganh cdng nghiep c h i tao may trong nUde hien nay edn r i t sd khai; nhdng v i n d l v l vat lieu, cdng nghe c h i tao chinh x i c , cdng nghe e h i tao linh kien v i t h i l t bj dien td... l i nhdng diem y i u ehii y i u eiia chiing ta.
Tuy nhien chiing ta lai ed nhdng y i u td thuan Ipi trong ITnh vyc hpp t i e qud'c t l v l ky thuat, v l kha n i n g nhap khIu cae vat tU phy tiing, linh kien dien tu... do dd ehung ta h o i n toan cd t h i e h i tao thanh cdng he dieu khien ty ddng day c h u y i n t h i l t bj thi cdng CXMD gia cd n I n d i t y i u phii hpp vdi quy trinh thi cdng hien h i n h , vdi trinh dp e h i tao trong ndde, d i p dng c i c yeu e l u kinh t l - ky thuat - xa hdi dang ddi hdi.
2. Cac giai phap dieu khien t d d p n g thiet bj 2.1. Kiim soat chieu siu cua CXMD
Viee ha v i rut c l n khoan trong qua trinh thi cdng CXMD dupe thuc hien nhd bd tdi tren m i y cP sd.
Nhdng day c h u y i n t h i l t bj thi cdng chUa ed he d i l u khien ty ddng, viee kiem s o i t c h i l u sau CXMD dupe thye hien thdng qua viee quan s i t eae vach chia c h i l u dai tren can khoan. Nhdng t h i l t bi loai n i y khdng the ty ddng dieu chinh lUPng xi mang ddng d i u tren toan bd the tich eoc.
Dau do dich chuyen Encorder
i k
Dp chuyen djch cua miai khoan
w Bo xir ly trung tam
y
r Hien thi chieu sau cpc tren man hinh
Hinh 1. sa dd kiem soat chieu sau CXMD.
Cum do chuyen dich mui khoan.
Cac t i e g i i da nghien edu t h i l t k l cym do chuyen djeh mui khoan cd sd dyng Encorder de do c h i l u sau cpc. Sd dyng Encorder eho k i t qua do vdi dp chinh x i c cao (dp phan giai tdi 1cm) v i thuan tien eho ty ddng hda, sd hda chieu sau cpc va hien thi tren m i n hlnh trong q u i trinh thi cdng.
2.3. Kiim soit trgng lugng xi ming phun De k i l m s o i t trpng lupng xi mang phun tdc thdi v i tich luy theo tdng CXMD, cae t i e g i i da sd dyng 03 loadcell do trpng lupng thung e i n xi m i n g . Nhd dd trpng Idpng xi mang ddpc kiem s o i t c h i t che va hien thi tren m i n hinh. Viee sd hda trpng Idpng xi m i n g la
CP sd quan trpng cho q u i trinh dieu k h i l n ty ddng.
Hinh 2. So dd kiem soit trong ludng xi mang phun via dat nen.
Loadcell do trpng Idpng xi m i n g
Bd xd ly trung t i m
Sy thay ddi trpng lupng thung djnh
lupng xi mang
Hien thj trpng lupng xi mang tren m i n hinh
2.3. Tuddng hoi viec ddng md cic van xi ming - khi
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Hinh 3. So dd nguyen ly kit cau cua he dinh Iddng phun xi mang va eae van xi mang.
DKi - Cac van xi m ^ g khi VMC - Van mpt chieu VDC1,VDC2-Van khoa
VAT - Van an to4n khi n^n DH - Dong ho ip suit khi nin MN - Miy nin khi
BL - Bau lpc tich nudc
Hinh 4. Sd dd dieu khien cic van xi mang khi
Nguyen ly l i m viec eua thiet bj djnh Iddng - phun xi mang dya tren nguyen ly van chuyen bang khi nen.
Qua nghien cyu thilt bj eiia c i c nude tren t h i gidi, nhdm nghien edu lya chpn sP dd nguyen ly l i m viec eiia t h i l t bj djnh- Iddng phun xi mang tren hinh 3 va so dd mach d i l u k h i l n khi nen tren hmh 4. Sd dyng cac xi lanh md men de ddng md c i c van xi mang - khi, dypc d i l u k h i l n ty ddng nhd c i c chuong trinh d i thiet lap s i n va c i i dat trong p h l n m i m d i l u Khien.
2.4. Sd dgng hg thing dieu khiin tudg^q thiit bi
KHOA HOC - CONG NGHE
Tap chi GTVT 7/2009
dinh lugng phun xi ming
He thdng thiet b\ thi cdng CXMD c l n phai dupe dieu khien tu ddng theo c i c ehUPng trinh d i dupe cai dat s i n . P h l n mem d i l u khien dupe xay dung theo quy trinh thi cdng CXMD hien h i n h . (TCXDVN 385- 2006). Chuong trinh d i l u khien dUpe xay dyng d dang md. C i e thdng sd d i e thy ciia tyng cdng trinh cy the dypc nap v i o chuong trinh d i l u khien theo giao dien tren m i n hinh thao t i c nhu dUdng kinh cpc, c h i l u sau cpc, trpng lUpng xi mang tren 01 met d i i cpc, sd l l n trdn... He dinh lUpng phun xi mang l i mpt trong nhung thilt bj quan trpng c l n ddpc dieu khien ty ddng. So dd khdi dieu khiln tu ddng he djnh lUpng phun xi mang dupe trinh bay tren hinh 5 n h l m d i l u khien tu dpng q u i trinh phun xi mang dam bao dp ddng d i u ciia hon hpp xi m i n g d i t va phy gia ( n l u cd) tren t o i n bd the tich cpc vdi sai sd khdng vupt q u i 5%; hien thj cac thdng sd thi cdng tren man hinh trong sudt thdi gian thi
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Hinh 5. So dd khdi he thdng dieu khien td ddng thief bi dlnh ludng - phun xi mang.
2.5. Tudgng dieu chinh lugng xi ming theo yeu eau Tren hinh 6 the hien sP dd ty ddng dieu chinh lupng xi mang phun theo tdc dp rut eiia mui khoan. Chieu sau ciia epe va trpng lupng xi mang phun tuc thdi da dUpc sd hda. Sd dung b i l n t i n de dieu chinh vd e l p tdc dp
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^ Loadcell
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quay eiia ddng eP d i n ddng ed c i u phan phdi xi m i n g nham thay ddi lupng xi mang phun vao d i t n I n .
Hinh 6. So dd td ddng dieu chinh Iddng xi mang phun thee tdc do rut mui khoan.
Trpng lUpng xi mang tren 01m dai cpc theo thilt k l ciia tdng cdng trinh cu t h i dupe nap vao p h l n mem dieu khiln ty ddng theo giao dien tren m i n hinh. Qua dd bd xd ly trung tam dieu khien b i l n t i n lam thay ddi tdc dd ciia ddng co dien dan ddng cP e l u phan phdi xi mang. Trpng lUpng xi mang phun v i c h i l u sau cpc lien tyc dypc truyin tdi bd xd ly trung tam. N l u lUpng xi mang nho hon yeu cau (hoac ngUpe lai), bp xd ly trung tam se dieu khien d l bien t i n thay ddi tan sd lam cho dpng CP dien thay ddi tdc dp quay v i lupng xi mang phun dupe d i l u ehinh eho tdi khi n i o trpng lupng xi m§ng tren tdng met d i i eiia epe d i m b i o yeu e l u .
Ben cgnh viec dieu khiln lUpng xi mang phun b i n g
each thay doi tdc dp quay ciia cO e l u phan phdi xi mang ngudi ta edn thay ddi i p suit khi nen "hda long xi mang"
trong thung can nham thay ddi hieu suat nap lieu.
3. Ket qua nghien cdu
Tu nhung yeu cau ciia cdng nghe thi cdng CXMD, cae tieu chuln thi cdng nghiem thu CXMD hien hanh, dya tren nhdng thanh tyu khoa hpe cdng nghe tren t h i gidi, kha nang va trinh dp cdng nghe che tao trong nUde.
Theo k i t qua nghien edu [1], nhdm nghien cuu da sd dung nhung thiet bj s i n cd trong nude nhu may cO sd, thilt bj e l p xi mang rdi, nhap thiet bj khoan ddng thdi c h i tao trong nude he djnh lUpng phun xi mang va he dilu khien de cd dUpc day chuyin thilt bj thi cdng CXMD vdi tinh nang ky thuat lien tiln cd the thay t h i nhap ngoai. C i e giai phap dupe de xua't dieu khien ty ddng thilt bi nhlm dilu khien va ty dpng hda t o i n bd cac hoat dpng ciia day chuyin thilt bj: Sd hda va kiem soat chieu sau ciia CXMD, trpng lupng xi mang phun vao d i t nen va hien thi tren man hinh trong sudt q u i trinh thi cdng; Sd dyng bien tan thay doi tdc dp quay ciia dpng co dieu ehinh lUpng xi mang phun; Ty ddng dieu chinh lupng xi mang phun theo tdc dp rut ciia mui khoan dam bao dp ddng deu ty le xi mang dat theo yeu e l u thiet k l vdi sai sd # 4%; Tu ddng ddng md c i c van xi mang - khi phu hpp vdi c i e thao tie; LUu gid ket qua thi cdng cho tdng CXMD. Mdt sd san pham thyc te do nhdm nghien cdu che tao dupe trinh bay tren hinh 7.
Thung ilinh lifpng Co cau phan phoi xi ming Bien tin di^u hhl^'n toe dA Min hlnh giao dien
Hinh 7. Mot sd ket qua nghien cdu che tao he dieu khien tu ddng thief bi thi cdng CXMD.
KET LUAN
Nghien cuu giai phap d i l u khien ty ddng thilt bi thi cdng CXMD theo cdng nghe trdn khd phyc vy gia cd nen mdng d Viet Nam nham che tao he d i l u khiln thiet bi dinh lUpng phun xi mang phu hpp vdi yeu c l u thyc te thi cdng, vdi trinh dp cdng nghe c h i tao trong nydc, vdi kha nang t i i ehinh edn han che ciia c i e nha thIu d nudc ta, dap dng yeu e l u kinh te - ky thuat la van d l c l n thilt hien nay.
Thilt bj dupe nghien cyu thiet ke va che tao hoan ehinh, da dupe thd nghiem tren mdt sd cdng trinh thi cdng nen mdng bUdc dau cho kit qua kha quan. Cac chi tieu chat lupng ciia thilt bi hoan toan phu hpp vdi yeu cau ciia cdng nghe thi cdng. D l nghj cac d p quan ly eho phep thiet bj dupe sd dung rdng rai thay t h i nhap ngoai •
TAI LIEU THAM KHAO
[1]. Nguyen Xuan Khang, Nguyen Chi Minh. Dinh hudng ve thiet bi thi cdng CXMD thea cdng nghe Iron khd phuc vu gia cd nen dat yeu d Viet Nam. Tap chi GTVT. Sd 3/2009.
[2]. Nguyen Xuan Khang, Nguyen Chi Minh Nghien cdu nhu ciu ve thiet bi thi cdng cac xi mang dat phuc vu cdng nghe gia cd nen dat yeu. Hdi nghi KHCN - Vien KH&CN GTVT Ha Ndi thing 7-2008
[3]. Hankan Bredenberg. Equypment tor deep soil mixing with the dry jet mix method. 1999 Balkenma, Rotterdam.
[4]. G. Holm. Applications of Dry Mix Methods far deep soil stabilization. 1999 Balkenma. Rotterdam.
