1111 TRAO B O I Y KIEN
AP DUNG PHUONG PHAP XAC SUAT THONG KE TRONG NGHIEN CUU HE s6 QUY DOI XE VE XE MAY TRONG DONG GIAO THONG H O N HOP
NHIEU XE MAY d VIET NAM
KS. THAI HdNG NAM PGS. TS. VU HOAl NAM
Bd mdn Dudng d td - Dudng dd thi, Dpi hpc Xay dyng
Tom tat: Bdi bdo ndy di xudt mdt phwang phdp khd dan gian di xae djnh he sd quy doi xe ve xe may cua cac phwang tien trong ddng giao thdng hdn hap nhiiu xe may Dwa vdo viee khao sat swphan bd cOa khodng cdeh bdm dpc, bdm ngang giOa xe mdy vd cac phwang tidn khac trong dong xe.nhdm tdc gia xdc dinh dwac dien tich khdng gian ddng (di0n tich ddng) cua cdc phwang tien. Tw dd xae dinh dwq/c he s6 quy dii ve xe mdy cua mdt sd xe trong dong giao thdng hdn hap nhieu xe may theo ti so giim dien tich ddng cua cac phwang tien va dien tich ddng cOa xe may.
Abstract: This paper proposes a fairly simple method to determine Motorcycle Equivalent (MCE) of the vehicles in mixed traffic flow with the predominance of motorcycles. Basing on an examination of the longitudinal following distance, the lateral following distance between motorcycles and other vehicles in the traffic flow, authors determine the area of vehicles's movable space (vehicles's movable area). From this, it is possible to determine MCE of some vehicles in the mixed traffic flow with the predominance of motorcycles to the ratio of vehicles's movable area to motorcycle 's movable area.
1. TdNG QUAN V A N D i NGHIEN CLfU Dong giao thdng hdn hpp cd nhung net daeJhu ridng, tren mdt lan xe ludn ed cae lopi phuang tien trdn lln vio nhau. Ly thuylt ddng xe tren t h i gidi hidn nay ehu yeu dupe ap dgng vdi ddng xe thuIn nhit l i xe con. Do dd trong qua trinh thilt k l , d l ap dung cic
\i/ thuyet san cd, ngudi ta quy dli cic loai phuang tien trong ddng xe ve mdt phuang tidn (PCU: xe con dan vj hope MCU: xe miy dan vj) de coi ddng xe hdn hap nhu mgt dong thuin nhat. Dudi day l i mdt sd kit qua nghien cdu dupe cdng bo:
a. Holroyd (1963) da wac tinh t i c ddng eua xe may din luu lupng bao hda v i t h i hien cic kit qua dudi dang PCU. Nghien cdu nay duac thye hipn tai chfn dja dilm va tim ra he s l quy doi tu xe may v l xe con dan vi trong giai doan bao hda l i 0,33.
b. Anard va cdng sy (1999) da de xult g i i tri xe con dan VI cho Malaysia, nai cd ddng giao thdng hon hap nhilu xe miy. Phuang phap niy xem xet nhung inh hudng cua thanh phIn giao thdng, t i c do v i quang each v& du'a ra cdng thuc xae djnh he s6 doi xe v l PCU tu cac loai phuang tidn khac nhu sau:
PCE - - W
Trong do:
PCE^ = hd s l quy doi ve PCU cua phuang tien i;
W,, W^ = Chieu rpng tin dudng eua phuang tidn i va xe con;
U,, U^ = Tie dp trung binh eua phuang tien i v i xe con;
t,, t^ = Quang each thdi gian trung binh eua phuang tien i v i xe eon;
t,, t^ = Quang each thdi gian trung binh cija phuong tien i va xe con.
He sd quy doi PCE cua mdt loai xe bit ky phg thugc vio tl so tie do trung binh giua xe dang xet v i xe eon. Cdng thde niy ehf dung khi toe dg eua xe con v i xe dang xet khac 0. Trong trudng hpp dudng xay ra tac nghen (tic dd = 0 hoac xap xl 0) thi cdng thirc quy doi trdn khdng the ap dgng duac.
c. Tiwari v i cdng sy (2000) quy doi cae lopi xe ve PCU cho dieu kipn cua An Dd bang phuang phap dieu chinh mat dp. Cac t i c gia do sy phan b l cCia moi loai hinh giao thdng tren chieu rdng mat dudng vdi cie loai dudng khac nhau cho cdng thuc nhu -F^xF^xF, (1.1)
PCE
wim
(1.2)
So 9 nam 2014 I
TRAO D 6 | y K|£N # # i Trong dd:
PCE, = hp so quy doi v l PCU cua phuang tidn i;
'^car' K ~ ^^^ ^9 ^'-'3 ^s con, phuang tien I, xe/km;
^Lcar- ^ ' - i ~ chieu rdng lan dudng cua cic tin dudng giao thdng ding nhlt xe eon, phuang tien i, m.
Trong ddng giao thdng hdn hpp nhieu xe miy, viee x i c djnh chieu rpng lin dudng va mpt dp (xe/km) ciJa xe miy l i rat khd khan. Vi vay, rat khd i p dgng cdng thuc nay de tim ra he s l quy doi xe trong ddng giao thdng hon hpp nhilu xe may.
d. Chandra va cpng sy (2003) da tiln hanh quy doi eac xe trong ddng giao thdng hon hap ve PCU. Gia tri PCE eua cac phuang ti§n khac nhau theo tinh trpng giao thdng hdn hpp ty Id thupn vdi ty Id toe dp va ty 1^ nghjch vdi ty' Id lip d l y khdng gian chiem dgng.
PCE.
V / v .
A / A . (1.3) Trong dd:
PCEj = He s l quy doi v l xe con cua loai xe i;
V^, V- = toe do eua xe con v i cua logi xe i, km/h;
A^, A| = dien tich chiem dgng tTnh cua xe con v i loai xe i trdn dudng (dii x rpng), m^.
Trong cdng thuc quy doi eua Chandra v i cpng sy hd so quy doi PCE phg thudc vao ti so dien tich chilm dgng tTnh cua cac loai phuang tien. Nhu vay, gia su xet 2 xe {1 v i 2) o6 ty so didn tich A1/A2 = 2. Xdt 2 trudng hap:
- THI: xe led toe dp U1 = 10 km/h ; xe 2 ed tie do U2 = 20 km/h.
- TH2: xe 1 cd t i c d0 U1 = 40 km/h; xe 2 ed t i c dd U2 = 80 km/h.
Neu ap dyng cdng thuc tfnh he s l doi xe PCE cua Chandra, trong ca 2 trudng hap PCE =1. Dilu n i y la khdng hdP ly vi khi toe dg cing cao, cac xe thudng duy tri khoang each vdi xe phia trudc v i ben canh cing Idn hay dipn tich dudng danh cho xe cing Idn.
CQng giong nghien cdu cua Anard trudng hpp dudng xay ra tie nghen (toe dp = 0 hoac xap xi 0) thi cdng thuc quy doi trdn khong the i p dgng dupe.
e. Phan Cao Thp (2004) da nghidn cdu he so doi xe trong nut giao thdng qua vipc nghien cdu "Khong gian ddng" - la khoang khdng gian c i n thiet d l xe chuyin ddng mot cich binh thudng vdi t i c do cua minh m i khdng bj va cham vdi cae phuang tidn khic, m^. Khong gian dgng phg thuOc vio hai yeu to
l i kfch thudc v i toe dd cOa xe. Ngoii ra toe dO xe chay ty" l§ thuan vdi khdng gian ddng nay. Hp so quy doi xe duac xae djnh trong nut giao thdng thdng qua khdng gian dgng dya tren hai ca sd l i ly thuyet x i p xe (phuang phap xIp xe cOa Zamakhaep) v i thye nghiem quan trie thye t l ngoii hien tnjdng tai mpt s l nut giao d Ha Ndi v i D i Nang. Nghidn cdu niy thu duac kit qua he giua khdng gian ddng eua cic xe (xe dap v i xe con) so vdi xe miy nhu sau:
Theo ly thuylt:
D ^ : D ^ : D ^ ^ = 1:0,67:1,67 Theo thye te quan trie:
D^:D^:D^= 1:0,72:3.90
Tac gia Phan Cao Thp d i tiln hinh doi xe dya vio dipn tfch ddng, diy l i c i i tien so vdi cic cich quy dli trudc day. Tuy nhien, tie gia mdi xae djnh dupe he so doi xe cho xe dap va xe con. H$ so dli xe eua xe bu]/t chua duac t i c g i i dua vio trong tfnh toin m i ch? duac liy theo tieu ehuin hien hinh tai thdi diem do eua nudcta.
f. Chu Cdng Minh v i cdng sy (2009) tiln hinh nghien cdu thye nghiem tai 3 vj trf dudng 2 lan xe khdng cd giai phan each, ed be rpng khac nhau, ddng giao thdng hdn hap ed han 85% xe miy. T i c gia d l xult quy d l i moi phuang tidn trong ddng xe ve MCU. Vi^c thu thap s l lieu trong nghien cdu dya vao viee su dgng phIn mem 5EV va dua ra cdng thde xae djnh hp s6 quy d l i v l xe m i y cua c i c loai phuang tien:
MCE - - ^ 1 ^ ^ ^ (1.4) Trong do:
MCE^ = Hd s l quy d l i ve xe may cOa phuang tien k;
V^ = Tie do trung binh cua phuang tien k (m/s);
S^^(V^), S^(V^) = Didn tich chiem dyng hipu qua eua 1 xe miy va 1 phuang tien loai k dng vdi t i c dg V^, Viee x i c djnh khdng gian dpng cua cie xe trong nghien cdu cua Chu Cdng Minh dya vio phan mIm SEV, diy l i phan mem phin tich so lieu giao thdng cho phep xae ^nh vj tri eua cic xe trong nhung khoang thdi gian thip. Tuy nhien, phan mIm nay chua p h i biln tren t h i gidi va d Vidt Nam hidn ehua ed phIn mIm nay.
Chinh vi vay, trong nghien cdu nay, nhom t i c gia dua ra mdt phuang phip dan gian han, d l i p dyng han khi nghidn cuu ve ddng giao thong hon hpp nhilu xe may d Viet Nam.
I So 9 nam 2014
mm
# # # # # TRAODOIYKIEN
2. PHU'aNG P H A P NGHliN CCKU V A K H A O S A T
s6
u|u2.1. Ccf s d phu>ong phap luan nghien cu>u Trong nghien cdu cue minh, tie gia xae djnh he so quy dli xe cua cic xe trong ddng xe dya vio vide xic djnh dien tich khdng gian ddng cua cic xe (giong [3], [5]). Tuy nhien, nghien cuu niy dua ra mdt phuang phip khi dan giin, dupe thye hi$n theo sa do sau:
chile xe dd chilm tren dudng khi nd chpy vdi mOt v$n toe nio dd m i khdng bj va cham vdi cic phuang tien khac. Trong phpm vi khdng gian dgng cua chile xe dang xet, khdng ed sy hien dien cOa bat ky chiec xe khac, t h i hipn trong hinh 2-2.
Thu thap so li?u
KCbam dpc, d
KCbam ngang, b X Xu Iv t h i n s ke L
^I5%< ^^0%. (^KS
T.
bi5%, bsn% bii5%
Khdng gian d0ng
^15%- ^50%, ^85%
He sd quy ddi ve xe may, MCE
Hinh 2.1. Sa do nghien cOv.
Khoing cich bim dpc giua xe miy va phuang ti§n nao dd theo nghien cdu niy dupe hieu l i khoing each theo phuang dge m i ngudi lai xe miy duy tri de bam sau phuang tien di trudc nhlm dam bio an toan. Khoang each bam dpc dupe tfnh tu mui chile xe may den dudi eua ehlee xe di tnj-dc, t h i hien trong hinh 2-2.
Khoang cich bam ngang giua xe miy v i phuang tien nio theo nghidn cuu niy l i khoang eich theo phuang ngang m i ngudi Iii xe may lya chpn d l tien hanh vupt hoac di song song vdi phuang tipn dd. Khoing cich bim ngang lln lupl dupe tinh la khoang cich giua 2 trgc dpc cua 2 chiec xe, khoing each td true dpc xe miy din thinti ben cua d td (xe con, xe bus) tuang ung cho eac trudng hpp xe miy bim ngang xe miy; xe may bim ngang 6 td, t h i hipn trong hinh 2-2a,2-2b.
Khdng gian ddng (S^) dupe hilu l i dien tfch m i
a. Trwang hpp bdm xe giu^ xe mdy - xe may
b. Trwang hgp bam xe giu^ xe mdy -xedtd Hinh 2.2. Khoang each bam dpc vd khoang each
ngang trong nghien cuv
Trong ddng giao thdng hon hap nhieu xe miy, xe miy cd tfnh linh hopt eao, ngudi dilu khiln xe may cd hinh vi rit phuc tap, hp eo the linh hoat dieu khien xe bim rIt g i n chile xe doi tupng (phfa trudc hoac ben epnh) khi cam thiy an toan, hoac ra xa khi cam thiy nguy hiem. Hay ndi cich khac, khoing cich bim dgc v i khoang each bim ngang ludn thay dli tuy thudc vio t i m ly cua ngudi Iii xe miy. Chinh vi vpy, nhdm tie gia nghien cuu sy thay dli cua khoang each bam dpc, ngang giua xe miy va cic xe cd kfch thudc khac nhau trong nhung dii tie do khac nhau. Dong thdi, su dgng c i e phuang phap thing kd toin hpc d l nghien cdu anh hudng eua tam ly ngudi Iii thdng qua vipc x i c djnh g i i tri cua khoing cich bim dgc, ngang dng vdi cic t i n suit tfch luy 15%, 50%, 85% trong tung d i i toe dg. C i c khoang each ung vdi tan suit tieh luy 15%, 50%, 85% dupe hilu l i khoang each ma 15%, 50%, 85% ngudi lai
m\^/m
So 9 nam 2014 1TRAODOIYKI£N i
lya chpn dudi cic g i i tri niy 6i bim theo chiec xe di tnjde hoac ben epnh. Cd t h i coi cic khoing each ung vdi t i n suit tich luy 15% v i 85% l i ngudng gidi hpn dudi v i gidi han tren ve khi nghien cuu ve khoing cich bam xe. Khi ngudi lai lya chpn khoing cich bim nhd han gia tri dng vdi t i n suit tieh luy 15% dupe xem l i c i bi^t. Cdn khi ngudi lai lya chpn khoang cich bam Idn han gii tri ung vdi t i n suit tich luy 85%, chile xe dang xet cd khoing cich vdi chile xe di trudc hoac bdn canh qua xa. Luc niy xem nhu ngudi Iii khdng chju anh hudng cua chile xe di trudc hoac ben canh. Khi da xic djnh duac cic khoang each ung vdi cae t i n suit do, de dang tim ra duac di^n tfch khdng gian dOng cue cic xe ung vdi cac t i n suit. Nhu vay, dien tfch khdng gian dgng eua mdt phuang tien cung cd ngudng dudi, tren tuang dng la dipn tieh khdng gian dgng ung vdi t i n suat tfch luy 15% v i 85%.
Hp s l quy doi eua eac loai xe ve xe may se tfnh toan duac khi x i c djnh duac di§n tich khdng gian dpng cDa cic xe. Cdng thuc xae djnh he so quy doi xe tu loai xe i ve xe miy duac x i c djnh dya trdn sy tuang duang v l dien tfch khdng gian dgng cua cae xe, cd dang:
ddng giao thdng do dd tie gii lya chpn H i Ndi nai thye hipn nghien cdu cua minh. Cic tuyin phi trong pham vi ngi thinh H i Npi hlu h i t l i ed ddng xe hon hpp. Nhdm tic gii i p dgng phuang phap tren vdi 1 tuyin dudng cu t h i thoa man cae tieu ehf:
+ Khdng to chdc phan lin, phan luong cic phuang tlpn de dam bio ddng giao thdng l i ddng hon hpp.
+ Gin cac cdng trinh nhi cao ting hope c i u vupt dim bio cd t h i d i t miy quay tu tren cao quan sat toin bd ddng giao thdng d l cd the nghien cuu cac s l lipu ein t h i l t
-I- Cd nhung dopn dudng eich xa eac nut giao de dam bao ddng xe khdng bj anh hudng bdi cac ddng xe tren tuyen dudng khac.
Nhdm tie gia lya ehgn dudng Chua Bgc l i dudng thoa man cic tieu ehf d l ra.
2.2.3. Trinh tip thiPc hidn khao sat
Tiln hinh khio sit thye nghidm theo cie bude sau:
Bude 1: Chuin bi nhung cdng cu, vat dgng can thilt.
Bude 2: Tien hanh ve ludi d vuong ed kfch thudc 2m X 2m tren doan dudng nghien cuu tai cac dja dilm.
M C R - ^ (2.1) Trong 66: '^'"^'^
lyCE, = He so quy doi ttp ioai xe i ra xe may;
S' = Dien tich l<hang gian flgng cua ioai xe I (m');
^ I m , , ^ Dien tich i<hong gian aang cua xe may (m^).
2.2. Khao sat so lieu 2.2.1. Phuvng phap khao sat
Hien nay co nhieu ky thujt de thu thjp so iiSu ve d6ng giao thong. Do I<h6ng co cac thiet bi co the thu thap tnjo tiep so li$u iir hien tivang nen tac gia SLP dung phu'ang phap trem quay co djnh (quay camera, chup anh hien truffng) va thu thap dO lieu tif cac video quay dipo'C. Day la phuang phap dan gian, de dang si> dgng va co dp chinh xae tu'ang doi cao.
Oe dam bao do chinh xae cCia phuang phap do, can xay dung tren mat duang mpt ludi 6 vuong co kich thuac du(?c xae djnh truae. Luai 6 vuong nay la ca sd de xae djnh tpa dp cua cac xe trSn ducrng eung nhu xao djnh duac khoang each giua cae xe.
2.2.2. Luy chon vj trf khao sat
Ha Npi la mpt thanh pho co ty le xe may cao trong
Hinh 2.3. Ve iu^i 6 vuong trin mat dumjg Buac 3: Lua chpn vj tri dat may quay. May quay duac dat a tren cae nha eao tang hoac cau vupl di bp.
Buo'c 4: Tiln hanh quay video tu luc 7h00' d4n 9h00' Buac 5: Xem lai video khao sat tr§n may tinh ea nhan vai toe dp cham de thu th$p so lieu.
2.2.4. Thu thap va phan tfch so lieu
Cac video thu duac tCp cupc khao sat duac xem lei tren may tinh ca nhan bang each sO dung phan mIm KINOVEA. Phan mem nay co the cho phep ta quay cham video vai toe dp bat ky, xae djnh duac th&i gian vai dp chinh xae 0,01s cQng nhu c6 the chyp anh tu video.
I So 9 nim 2014
©IBJiSIHI®
taatg TRAO DOI Y KI^N
a. Tic dQ
De xae djnh t i c do tuc thdi, tic g i i lya ehgn chieu dai biy l i 6m (chieu dai 3 d ludi). Su dyng phIn mIm KINOVEA d l xic djnh chfnh xae thdi gian xe bat diu v i o chieu dii "biy" v i thdi gian xe ra khoi chilu dii "bay". Ket qua thu dupe, toe do eua hlu hit cic xe tpi vj tri nghien edu la tu 20 km/h den 35 km/h.
b. Khodng cdeh bdm
Tie gii tiln hinh nghidn cdu v l khoang cich bam dgc v i khoang each bim ngang giua cac xe trong cic dii toe dg: 20-25 km/h; 25-30 km/h; 30-35 km/h.
Nhpn thay xe dap chiem ti Ip rit nhd trong thinh phIn ddng xe, van toe thap, kfch thudc nhd va hlu het ngudi di xe dap thudng di sit vao phin l l cCia dudng ndn xe dpp it gay anh hudng den tfnh chit cOa ddng xe hdn hpp. Chinh vi vpy, trong nghien niy khdng xet din khoing eich giua xe dpp va lopi xe khic.
Nhdm tic gii nghien cuu khoing each bim dgc, khoing each bim ngang giua xe may - xe may, xe miy - xe con va xe may - xe bus. Vdi mdi dii t i c dO, nhdm t i c gia thu thpp s l li§u ve khoang cich bim dgc, khoing cich bam ngang cua 100 cap xe. Vipc thu th^p s l lieu khoing each bam bIng cich dim s l lin xult hien khoang each bam trong cic d i i khoing each (khao sit khoing eich bim dge vdi eac dai khoing cich cd bude 0,5m; khao sat khoing cich bim ngang vdi dai khoang eich ed bude 0,2m).
Nhin thay trong mpi dii t i c do, khoang each bam theo phuang dgc, ngang deu cd phan bo ehuin.
2»
v
gis-
•- 10-
- j " \
1^
/
y • jHg
H
1
•g
B ^r
H-IOO
^ ^
^ ^ ^ H
t
liX) 250 liX) JS) 4011 4 » Khoing cAchbtm(ni)
!!»
ZZ.
g «~
\mm
/i
-—t /
-A
<lo •1.Hinh 2.5. Do thj tan suit tieh luy khoang cdeh bdm dQC giim xe mdy - xe con vai dai toe do 20-25 Km/h Khoang cich bim dpc v i ngang ung vdi tan suit 15%, 50%, 85% giua xe miy - xe con, xe miy - xe miy, xe miy - xe bus vdi c i c d i i t i c dO khic nhau dupe the hipn tu bang 2-1 din bing 2-3 Bang 2.1. Khoang each bdm doc vd bam ngang suit 15% vai cac dai toe dd khdc nhau
DJi t6c ap (km/h)
20-25 25-30 30-35
Xe may - xe con KCbam doc (m)
1.80 1.81 1.93
KCbam ngang (m) 0.76 0.81 0.86
Xe m^y - xe may KCbSm d9c(m)
0.86 0.91 1,00
KCbam ngang (m) 0.92 0 96 0.98
Xe mdy - xe bus K C b i m doc(m)
1.85 2.02 2.02
KCbdm ngang (m) 0.79 0.82 0.88 Bing 2.2. Khodng each bdm doc va bam ngang suit 50% von cdc dai toe dQ khdc nhau
D i i t6c dp (km/n;
20-25 25-30 30-35
Xe may - xe con KCbam dpc(m}
2.61 2.75 2.95
K C b i m ngang (m) 1,15 1,19 1,23
Xe mdy - xe mdy KCbSm dpc (m)
1,61 1,71 1,83
K C b a m ngang (m) 1.24 1,30 1,32
X e m d y - x e b u s KCbdm dgc (m)
2.82 3,00 3,09
KObdm ngang (m) 120 1,22 1.27 Bing 2.3. Khoang each bim dQC vi bim ngang suit 85% vo'i cic dai toe d0 khic nhau
Ddi toe dp (km/h)
20-25 25-30 30-35
Xe may - xe con K C b d m dpc(m)
3.63 3,80 4 03
K C b d m ngang (m) 1.53 1,57 1,62
Xe mdy - xe may K C b d m dpc (m)
2,50 2,54 2.60
K C b a m ngang (m) 1.62 1,63 1,66
Xe mdy - xe bus K C b d m dpc(m)
3,83 4,00 4.13
KCbdm ngang (m) 1,60 1.63 1,65
Hinh 2.4. Bo thi tin suit phan bo khoang cich bim dgc g/fla xe may - xe con vdi dii tic do 20-25 Km/h
Xic djnh ki'ch thuac dOng i>ng vb-i eac tan suat ticli luy 15%, 50%, 85% cua tCrng loai xe vai cac dai vgn toe. The hien trong bang 2.4.
mm
S6 9 n§m 2014 ITiRAO DOI Y KifiN i n Bang
Dai t6ca6
20-25 25-30 30-35
2.4. Kich thwdc dgng cua cac xe
Kich Hlu'oc dpng cua xe con (m) S u i t 15%
Rpng 2.52 2.62 2.72
Dai 6.30 6.31 6.43
rtung vi (50%) ROng 3.30 3 38 346
Dai 7.11 7,25 7.45
Suat 85%
Rpng 4.06 4,14 4,24
Ddi 8.13 8.30 8,53
(mg vol cic dii tdc do khic nhau
Kich thu'd'c d$ng cua xe may (m) Suat 15%
Rpng 1.14 1,22 1,26
Dai 2,66 2,71 2,80
Tnjng vj (50%) R«ng 1,78 1,90 1.94
Dai 3.41 3,51 3,63
Suat 85%
Rpng 2,54 2,56 2,62
Dai 4.30 4,34 4 40
Kich thuac dpng xe bus (m) Suat 15%
Rpng 3.38 3,44 3.56
Dai 12,57 12,74 12 74
Trung vj (50%) Rpng 4,20 4,24 434
Dai 13,54 13,72 13 61
Suat 85%
ROng 5,00 5,06 510
Ddi 14,55 14,72 14,85
Sau khi xae djnh duac kfch thudc ddng eua xe, tiln hinh xic djnh dien tfch dpng eua xe dng vdi cic dii vin toe khic nhau va thay vao cdng thde 2.1 cd 6\J!<?c hp sd quy d l i xe cua cae phuang tipn. The hien trong bing 2.5
Bang 2.5. Didn tich ddng cua cdc xe v&i cac ddi tic dd khac nhau
Ddi toe do (kmfli) 20-25 25-30 30-35
Dien tich dOng cua xe con (m') Suat 15%
15,88 16.53 17.49
S u i t 50%
23.46 24.51 25.78
S u i t 85%
33.01 34.36 36.17
Dign tich dpng cua xe mdy (m=) Suat 15%
3,03 3.31 3.53
S u i t 50%
6 07 6,67 7,04
S u i t 85%
10.92 11.11 11.53
Dipn tich ddng cua xe bus (m^) S u i t 15%
42.49 43,83 45 35
S u i t 50%
56.87 5 8 1 7 59,94
S u i t 85%
72 75 7448 75,74
Bdng 2.6. H$ so quy doi vi xe mdy cOa cdc loai xe vdi eac tin suit trong cdc dai tic do khde nhau Ddi toe d$ (km/h)
0 20-25 25-30 30-35
M C E , „ Suit 15%
6,07 5.24 5.00 4.96
Suit 50%
6.07 3.87 3.67 3,66
Suit 85%
6.07 3.02 3.09 3.14
MCE^.,^
Suit 15%
21.27 14.01 13.26 12.86
S u i t 50%
21.27 9.37 8 72 8,51
S u i t 85%
2 1 2 7 6.66 6.70 6.57
Trong mdt d i i t i c dp, hp s l quy d l i xe dng vdi cic tan suit khac nhau chenh lech khi Idn chdng td t i m ly cua ngudi lai ed anh hudng nhieu d i n vide tinh toin quy d l i xe. Tic g i i kiln nghj su dyng he s l dli xe ung vdi tan suit 50% l i hp s l doi xe dai dien cho eac dai tie dp.
Bdng 3.1. Kiin nghi hd so quy dii vi xe mdy eua cacxe
Dai toe do (km/h) 20-25 25-30 30-35
MCExe mdy
1.00 1.00 1.00
lilCExe con
3.87 3.67 3,66
MCExe bus
9,37 8.72 8.51
So sanh h$ so quy doi xe kien nghj vdi TCXDVN104-2007 [6], nghien eiiu cda Phan Cao Thp [5], Chu Cong Minh [3]. Day la nhtpng nghien Cliu doi v*i dong giao thang hon hap a Viet Nam.
Tac gia tiln hanh so sanh tr§n dai toe dp V=25-30 km/h.
Nh$n thay. h§ so quy doi v l xe may cua xe con trong nghien cuu nay kha sat vai [5], 16] va 16'n han gia trj trong nghi4n cuu cua Chu C6ng Minh (khoang 1.5 lan). He so quy doi ve xe may ci3a xe bus trong nghiSn a>u nho han trong [5], [6] (khoang 0,7 lan) va
NCct.Tlc,i. TCXOVNI04-za>T nmCoTb, an,Cte(N4iiA
Hinh 2.6. He si quy doi xe MCU cua mot so tidu chuan, nghien cuv
ian han gia trj trong nghifin cuu cua Chu C6ng Minh {khoang 1,3 lan).
3. K£T LUAN
Phuang phap xae djnh he so quy doi xe dua tren khao sat su phan bo khoang each bam dpc, bam ngang dupe thuc hien dan gian, de dang ap dung.
He so quy doi xe MCE cua cae phuang tien thay doi tOy thuOc vao tam ly eua nguai lai xe, dao dpng tij' gia trj MCE ung vai tan suat tieh luy 85% den gia trj MCE tpng vai tan suit tich luy 15%.
De CO ket qua chfnh xae ve he s6 quy doi xe theo phuang phap nay, can phai duac tiln hanh khao sat thuc nghi#m tai nhilu con duang c6 cic dac dilm ve hinh hpc, t l ehuc giao thong khac nhau vai cae dai toe do khac nhau •
I So 9 nam 2014
