XL/LYCAC KHE BIEN DANG CUACACHAMOL/ONGBO
TRONGTHANHPHO
DoThuyDang
ABSTRACT
Despite ofvehicular tunnels, but in cit- ies, they still can satisfy higher require- ments: be can waterproof and prevent
unequal sinkings.
This article bring up a common means in order to treate srinkage slits ofve- hicular tunnel in every city and especial
means for treating shrinkage slits of in Dai Co Viet - Kim Lien of Ha Noi capital,
following these hiher requirements
DoThuyDang Nha F4, Tap the Dai hoc bach khoa
Ha Noi Di dong: 091 276 3260
1. Dat van de
Khi xay dUng dUdng ham giao thdng cd chieu dai Idn hon chieu rpng khoang (5 -i- 10) lan trd len, de phong tranh nhung hu hai ket cau vd ham do lun khdng deu, eung nhu do bien dang dpe qua Idn; ngUdi ta thudng phai phan chia dUdng ham thanh nhdng doan thich hop va de khe bien dang gida chung. Trong dd cac trudng hpp can chu y de khe bien dang nhat la:
- Oat da xung quanh ham yeu va nam trong tang nude trpng lUc.
- Anh hudng cua nhiet dp xung quanh cd sU khae nhau theo chieu dai dudng ham.
- Moi doan ham di qua 1 tang dat da ed tinh ben va tinh bien dang khae biet nhau.
- Tai trpng tinh dpe dUdng ham cd dac tinh phan bd tao budc nhay dang ke.
- Oudng ham cho luu thdng nhieu Ipai xe cp cd trpng tai khae biet nhau, cd kha nang gay ra tai trpng di dpng bien ddi Idn.
Chung ta deu biet, theo phuang dpe true dudng ham, chieu dai eua moi doan ham la rat Idn so vdi chieu dai mdi khe bien dang, vi the dp bien dang tuong ddi eua be mat xung quanh mdi doan ham la rat nhd so vdi dp bien dang tuong ddi cua moi khe bien dang. Cdn theo cac phuang vudng gdc vdi true doc dudng ham, trong khi dd bien dang tuong ddi tai mdi diem cua be mat
xung quanh mdi doan ham la it ed khae biet theo phuong va chieu;
thi dp bien dang tUOng ddi tai moi diem eua khe bien dang, neu khdng cd nhdng bien phap khdng che dac biet, lai thudng ed sU khae biet nhau theo ca phuong va chieu, tham ehi ed the tao su lech true va sU map mo tai day.
Rieng cae ham dUdng bp trong thanh phd, cung nhU cac ham chat lupng cao khae (ke ca cac ham ngudi di bd va ham dUdng xe ca gidi) do luu lupng giao thdng Idn, yeu cau ve sinh, my quan, dp em thuan va an toan ehdng tran trUpt cue bd deu can cao hon; cho nen cdn phai dam bao ehdng tham dot toan phan va dam bao dp em thuan eua be mat ben trong toan vd ham (ke ca tai cac khe bien dang), vi the mpi khe bien dang d day khdng nhdng phai dupe ehdng tham dot day du, ma cdn phai dupc ehdng su bien dang tuong ddi theo eac phuang vudng gde vdi true dpe dudng ham nda.
Xem xet dieu kien lam viec va dac tinh kien true eua ham dUdng xe CO gidi Oai Cd Viet - Kim Lien (Ha Ndi) (*), chung ta thay rd: de phdng tranh hu hai ket cau vd ham do lun khdng deu, cung nhu do eo ngdt va dan nd vat lieu; dUdng ham rat can duoc phan chia thanh cac doan va de khe bien dang gida chung. Han nda, day la ham dudng xe co gidi khdng nhdng nam gida Idng thu dd Ha Ndi, ma cdn nam trong 1 khu vUe 82JSWPiTl^f . 8.2009
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Hinh 1. Vet 6 ti/ang va giai phan each cua ham di/crng xe ca giai Dai Co Viet - Kim Lien (Ha Noi) do nudc tham dot qua khe bien dang [1].
CO canh quan va cdng trinh kien true dep (Cdng vien Thdng nhat, Cdng vien Hd ba mau, Trudng Oai Hpc Bach Khoa), cho nen toan dUdng ham, ke ea cac khe bien dang deu phai dugc ehdng tham dot va dupe ehdng cat trupt mdt each triet de.
Hien tupng cac khe bien dang d day bi tham dot va bj lun khdng deu (hinh 1) la khdng cho phep.
Tren thUe te, de dap Ung mdi nhiem vu ehdng tham dot va ehdng cat trUpt khdng deu tai cac khe bien dang nay deu cd nhieu bien phap khae nhau.
Rd rang, trong trUdng hop nay, viec ehdng tham dot va ehdng cat truot khdng deu rieng eho be mat xung quanh moi doan vd ham la de dang hon rat nhieu so vdi viec vda ehdng tham dot, vUa ehdng sU thay doi tuang ddi vj tri cac true dpe eua 2 mat cat ngang vd ham cung chan 1 khe bien dang.
TU dac diem kien true va cau tao eua ham dudng bd trong thanh phd ndi chung va ham dUdng xe eo gidi Dai Cd Viet - Kim Lien (Ha Ndi) ndi rieng, de tiet kiem, chung ta thay ed 2 nhiem vu ehdng tham dot va ehdng c^t trupt (do lun cue bd) cho loai ham dudng bd trong thanh phd nay:
- Cdng hda tUng doan vd ham va ehdng tham dot rieng cho tUng doan vd ham dd.
- Chdng cat trUpt ngang va tham dot rieng cho moi khe bien dang.
Trong bai viet nay, chung ta chi tim hieu phuong an kha thi de chdng tham dot tai cae khe bien dang, nhUng van gid dp em thuan eho be mat ben trong dUdng ham.
2. Chpn phuong an kha thi Neu tang edng toan bd vd ham rdi ehdng tham dot ddng bd eho toan vd ham dd bang cung 1 phuong an (vd chdng nhieu Idp so le nhau, cd dem each nUde gida cac Idp, ket hop vdi mang each nude bao ngoai) se rat tdn kem.
Can chu y rang, nhdng ket cau polyme cd nep nhan ed dp ben va dp dan hdi rat Idn vda chdng tham vda ehdng eo gian thdng thudng (ke ca kieu de phu ngoai va kieu de chon trong ket cau vd chdng [2]), tuy cd kha nang dng dung rat cao vdi eac mat cau, dudng Id thien va nhdng cdng trinh ed khdng gian thi edng Idn, cung nhu nhdng cdng trinh de ngdng hoat ddng de sda chda; nhUng chung deu chUa thich Ung sd dung cho dudng ham xe co gidi trong thanh phd ndi chung, dac biet cho dUdng ham xe co gidi trong khu trung tam eua Thu dd Ha Ndi ndi rieng. Day la dieu de nhan biet: mdt mat bdi chung deu khdng du kha nang chdng cat va dam bao lap day khdng gian mdi, sau khi he thdng vd chdng dudng ham bi lun trupt khdng deu theo cac phuong vudng gde vdi true dpe dudng ham;
mat khae bdi chung deu nhanh gia
va khdng cd kha nang lam viec lau dai bang ket cau vd chdng dUdng ham. Rd rang, eac phuang an xd ly khe bien dang nay khdng nhdng ehi tang chi phi ban dau va chi phi sddung dUdng ham len cao, ma cdn anh hudng rat Idn den td chde giao thdng cua khu vUe cd dUdng ham.
Trong hoan canh nay tdt nhat la chdng tham dot va chdng chuyen vi tuong ddi theo phUOng vudng gde vdi true dpe dudng ham tai khe bien dang theo phuong an: ket hpp vUa tang eUng eho dau cac doan vd chdng dUdng ham tai khu vUc can ke khe bien dang vda ehdng nudc tddat da xung quanh xam nhap vao khe bien dang dd.
2.1. Khi thi cdng vo chong dUdng hdm mdi
Ket hpp ehdng eat trupt va chdng tham dot qua khe bien dang kep gida 2 doan ham lien tiep bang phuang an: dung dng Idng cd cae gd chan nudc ket hop vdi vat lieu each nude lap day cae khe ket eau va mang each nude theo toan bp mat ngoai vd ham (hinh 2).
Theo phuang an nay, quy trinh thi cdng thudng cd eac budc ca ban sau day:
- Chuan bi va thi cdng phan mang each nude ea dUdi day cUng vdi eac thanh ben ngoai ket cau dng Idng.
- Chuan bi va thi cdng lien tiep phan day cung vdi eac thanh ben
iSVnTl^T . 8.2009 83
ket eau dng Idng.
- Chuan bj va thi edng phan day cUng vdi cac thanh ben eua cac doan vd ehdng dUdng ham nam trong ddt dng Idng da cd.
- Chuan bj va thi edng phan ndc cac doan vd ehdng dudng ham nam trong ddt dng Idng theo thiet ke.
- Chuan bi va thi cdng phan ndc eua ddt dng long theo thiet ke.
- Ket hop phut tram vat lieu each nudc vao khoang trong gida dng Idng vdi cac dot vd ehdng dUdng ham va xam chen hdn hpp xa dan hdi vdi vat lieu each nude vao khe bien dang gida cac doan vd chdng dudng ham.
- Dan bang che lap khe bien dang, tao su em thuan eho mat trong eua vd ehdng dudng ham.
- Chuan bi va thi cdng phan mang each nude bao ngoai ea dot dng Idng cung vdi cae doan vd ehdng dUdng ham theo thiet ke.
- Hoan thien trong va ngoai dudng ham.
Khi ap dung phuong an nay cho phep vUa tao dupe mat ddc thoat nudc ben ngoai vd ham va gd chan nudc thich hop eho cae mat ke ben moi khe bien dang, vda sddung vat lieu chdng tham truyen thdng la bi- tum lap day khoang trong gida vd ham va dng Idng, vda cho phep sd dung vat lieu lam mang chdng tham bao ngoai dng Idng la eung loai vdi mang ehdng tham vd ham, mac du phai ddng thdi bao ngoai ca 1 phan mang ehdng tham vd ham.
2.2. De hoan thien khe bien dqng dudng hdm Dai Co Viet - Kim Lien
Qua trinh ehdng tham dot va ehdng cat trUpt tai khe bien dang eua dudng ham nay ed the tuong Ung theo 2 trudng hop sau:
TrUdng hap 1- Neu khdng eho phep dao dat da vay quanh:
- Ket hop khoan phut ep vda tang edng ket hpp vdi tao ra tang each nude trong dat da xung quanh dudng ham tU nhdng diem thuan loi ca ben trong va ben ngoai dudng ham.
- Xam khe bien dang (kieu xam 84iS»nTl^f . 8.2009
Hlnh 2. Scf So phirong an xif ly khe bien dang cua cac ham Mng bp trong thanh pho.
1 - Mang each ni/oc giiJa ket cau vo chong duong ham va dat da vay quanh.
2 - Ong long BTCT de chong sir lun trust khong deu giufa 2 doan vo chong lien tiep (theo cac phuang vuong goc vdi true doc di/ong ham).
3 - Dean vo chong thijf N ciia di/dng ham.
4 - Vat lieu lap day khe bien dang de chong n't gio va tao sir em thuan (dam bao my quan) cho be mat ben trong cac doan vo chong lien tiep cua dudng ham.
5 - Doan vo chong thu (N -i-1) cua dutJng ham.
thuyen go) bang hon hop xa spi vdi nhua (hoac bitum) each nude.
- Oan bang nhUa che lap khe bien dang va son trang tri be mat ben trong dudng ham.
Trudng hop 2- Neu cho phep dao dat da vay quanh:
- oao dat da vay quanh.
-Tao mang each nudc ben ngoai phan he thdng cae tUdng dng Idng va cae tudng vd chdng dudng ham
-Tao cac gdchan nude ben canh cae khe bien dang. Rdi xay dung phan dng Idng ben cac tudng va ndc vd chdng dudng ham.
- Lap day ca khoang trong gida dng Idng va vd chdng dudng ham cung vdi khoang trong cua khe bien dang.
-Trai mang ehdng tham bao phu mat ngoai toan he thdng ndc dng Idng va ndc vd chdng dudng ham dang Id ra.
- Khoan phut ep vda tang cdng ket hpp VOi tao ra tang each nude trong dat da sat dudi nen dudng ham.
- Lap day xung quanh, hoan tra mat dudng va hoan thien ben trong ham.
3. Ket luan
NhUng xd lech va tham ddt tai
khe bien dang eua ham dUdng bp tuy khd ed kha nang gay ra nhung su ed nghiem trpng va nhdng tai nan bat ngd, nhung ehae chan se lam giam tinh my quan va lam giam kha nang phue vu (nhat la kha nang thdng qua) cua ham dUdng bp trong thanh phd.
Khe bien dang eua ham dUdng bd trong thanh phd phai ket hop dap dng ca yeu cau chdng tham dot va yeu cau chdng chuyen vj tuong ddi gida eac doan ham ke ben, eho nen eac phuong an chdng tham dot khdng kem phuong an tang kha nang ehdng lun trupt khdng deu (ke ca phuang an neu trong [2]), ndi chung deu ehUa thda man dupc cac yeu eau dat ra. Tren thue te, kha thi nhat la phuong an dam bao an toan theo sudt qua trinh sd dung dUdng ham: dung dng Idng cd cac gd chan nudc ket hop vol mang each nude theo toan bd mat ngoai vd ham
(hinh 2). •
TAI LIEU THAM KHAO 1-Vietnamnet&VNE 4/8/2009.
2- www.quocthangco.com.vn
