Tap chf GTVT 5/2012
NGHIEN CUTU NGUYEN NHAN VA DE XUAT MOT SO GIAI PHAP XUf LY SUT, TRlTOfT TREN DlTfllNG HO CHI MINH - DOAN QUA TINH GIA LAI VA KONTUM
Torn tat: Trong qui trinh khai thkc dudng Hd Chi Minh - do^n qua tinh Gia Lai vk Kon Turn, trong nhOng nSm gin dky da xiy ra hi$n tUdng sijt, trUdt nghidm trgng ta luy ndn dudng, nhdt Ik vko mOa mua bao. Bki bko se tim hidu ckc nguydn nhkn giy ra hi$n tUdng nay vk dS xudt mdt sd giki phkp khic phijc.
Summary: During exploitation of Ho Chi Minh road - the section through Gia Lai and Kon Turn provinces.
there has been serious collapse, sliding to road bed talus especially in rainy seasons. The article will study reasons causing this phenomenon and proposes some solutions.
1. Gidi t h i | u v l dUdng H 6 Chf Minh va cdc hidn tu^ng syt, trU^t
Dy dn dau tu xdy dyng dudng H i Chf Minh Id mdt trong cae dy dn quan trpng qud'c gia dUpe Q u i c hdi thdng qua chij trUdng d I u tU xdy dyng t^i Nghj quyet s l 38/2004/QH11 vdi tdng chieu dai 3.167 km.
Giai doan I (2000 - 2007), dUdng H i Chf Minh da dupc dau t u hodn chlnh vdi quy md 2 Idn xe, bao g i m cd kien c l hda vd c h I n g sgt Id dogn tU Hda Lac (Hd Ndi) d i n Tdn Cdnh (Kon Tum).
Giai doan II (khdi cdng ndm 2007- 2010) vdi m y c tieu noi thdng todn tuyen tU Pdc Bd (Cao Bdng) d i n D i t Mui (Cd Mau).
Giai dogn 111 (tU ndm 2010 - 2020): Hodn eh?nh todn t u y I n vd tUng budc xdy dUng cdc dogn tuyen theo tieu c h u I n cao tdc phu hpp vdi quy hoach dUpc duyet va khd ndng n g u I n v I n , trong dd luu y k i t ndi vdi quy hoach he thdng dUdng s i t , dudng ngang vd eac quy ho^ch khdc cd lien quan.
D i n nay, dy an dudng H i Chf Minh dang xdy dyng trong giai doan 2 vd dua vdo khai thdc cdc dogn t u y I n da xdy dung xong. Trong qud trinh khai thdc dd bdc id n h i l u van d l d n xem xet, ddc bidt Id v l n d l sgt, trupt taluy nen dudng hdng ndm vdn xdy ra, nhdt Id vao mua mUa bao.
Sut tru<ft xky ra t?i rdt nhidu vi tri tren tuyen dudng vdi quy md khkc nhau vk rdt da d?ng, trong sd dd tidu bidu Id cdc vj tri sau:
• Doan D i e Zdn - D i e Pet (Km334+000- Km365+425.29): T i n g so doan xdy ra syt trUpt khoang 20 dogn. Hien tupng syt trUpt trong doan nay xdy ra rat phUc tap va cd h l u h i t cdc logi hlnh d i t sut. Sut trUpt chCi y l u xuat hi^n 6 khu vpc ddo Ld Xo tgl cae vj trf Km334+430 - Km334+630, Km336+90 - Km336+257, Km345+781 - Km345+900.,. Cdc khe nUt tdch x u l t hi$n trdn b l mdt mdi ddc Idm gidm sdc khdng cdt cCia d d , de dpa m i t I n dinh mdi d i e , hidn tupng nay x u l t hidn tgi Km354+680 - Km354+838, Km334+338-Km334+393, Km345+200- Km345+440, Km345+466 - Km345+587... Cdc khe xdl t r l n dinh
TS. L § VAN BACH TrUdng D$i hgc Glao thdng V$n tai
mdi d i e eOng x u l t hl$n t^i Km336+90 - Km336+257, Km337+714-Km337+790,km344+338-Km344+393..:
- Dogn Khdm Dulc - D i e Zdn (Km303+000 - Km334+000): T i n g s l cdc d i l m syt trUpt khodng 15 d i l m , trong dd t g i c d c vj trf da b l trf c i t e d v l n xdy ra syt trupt nhu doan Km309+694 - Km309+765, Km309+795 - Km310+35, Km310+227 - KmSI 0+217, Km325+000 - Km325+150.,. Do phdi t h i l t k l nan chTnh t u y I n ndn tim dudng ra sat mdp sudi ddn ddn taluy dm bi xdi Id.
Hinh 1. TrOift 6£t Hlnh 2. Sy( Id aSt 66 "/nh 3. DSt s^t Id mil ddc t9l chSn xiy ra W khu vtfc f^" 9"« '"^"9 chin d6o Sa Mu Khe Ve ' * ' ''''^" ^^° ®^ ****
Qua mdt so thdng kd 6 tren ed the thay tinh hinh sut trupt trdn dudng H i Chi Minh Id khd nghidm trpng vd ddi hdi cdc cd quan ehUe phai cd nghidn eUu xO 1]^
cu t h i . Ddy Id tuyen dUdng quan trpng vd se cdn dUde md rdng, ndng cap trong tUPng lai. Vi vdy vide xdc djnh chinh xac nguyen nhdn gdy syt trUpt va d l ra dupe bidn phdp xCf \^ tridt de Id rat e l n t h i l t .
2. Nguydn nhdn gay ra hidn tU^ng sut, trUpt tren dUdng H i Chf Minh - Doan qua tinh Gla Lai va KonTum
Hidn tupng syt trupt tren dUdng Hd Chi Minh, dogn qua khu v y c tinh Gia Lai - Kon Tum r i t da dang, tuy nhidn ed t h i phdn ra 3 nguydn nhdn chfnh nhu sau:
- Do dnh hudng cCia cau true dja chat.
- Do dja hlnh va dd d i e taluy nen dUdng.
- Do dnh hudng ciia nudc mat vd nUdc n g l m . 2.1 Anh hudng cua cdu trdc dja chdt Ddc diem d u true dia c h i t cOa khu vyc Gia Lai - Kon Tum Id mdt trong nhufng nguydn nhdn chfnh d i n d i n h i l n tupng syt trUpt tai khu vyc nay. Cdc Idp dat dd cd thdnh p h i n thgch hpe chu y l u Id cdt ket, sdi k i t , cudi k i t v l n bj vd n h l u vd nuft rgn k i l n tao, Igi chju thdm tdc dung cCia phong hda da trd thdnh cdc ddi lis khdi tdng d i n v y n min vdi khd ndng chju lye kem vd tfnh tham nude eao. Dudi tdc ddng bd't ldi cua nude mdt vd nUde n g l m , khd ndng chju lyc Gua-mdl d i e vdi thdnh phan dja c h i t gom cdc ddi ndy cdng suy g l i m ddng ke.
Khi edn nam nguyen tgi c h i chua khai thdc thi Idp vd phong hda cd the dUng yen vd v i n I n dinh, nhUng do con ngudi khai thdc ddo chdn mdi doc da lam mdi ddc mdt khdi chdn ty, k h i ndng chju lyc cOa mdi ddc kem ddn d i n hinh thdnh sy chuyen dich cCia idp vd phong hda gdy ra hidn tUpng sut trupt.
^ 3 I KHOA HQC - C 6 N G NGHg
2.2 Anh hudng ciia dja hinh vk hinh dfing mkl taluy
Theo TCVN 4054-05, dd die cCia mdi dUdng ddo phy thudc vdo dilu kidn clu tgo dja chit vd chilu cao eCia mdi taluy, cy t h i nhu sau (Bdng 1):
Tuy nhidn, trdn dudng H i Chf Minh hi§n nay, dp ddc mdi taluy ddo hidn dang si!r dyng hlu hit dIu Idn hdn dd die eho phdp, chilu eao mdi taluy nln dudng ddo eung Idn hdn nhilu so vdi quy djnh trong quy trinh TCVN4054-05. Vide thilt k l ddnh b$e d p trdn mai taluy d l tdng d | I n dinh mdi taluy chua dUpc thyc hidn dly dO. Ding thdi d u tgo dja chit cdng trinh khu vyc dudng H i Chi Minh dogn qua tinh Gia Lai - Kon Tum eung rit phUc tgp, chilu ddy ting phO Idn vd thay dli, t h i nlm cOa dit dd nhilu khi die ra phfa ngodi sudn die, gdy bit Ipi eho I n djnh mdi die. TU dd ddn din syt trupt thUdng xuydn xdy ra vd khd kilm sodt.
Bkng 1
LoQldtfl OA 1 Dd cdng - Dfic6 phmglKia nhe - T>S dh phong b6n 2. d i e lo^i dA ht phong IM^D 3. Dd rOl rpc 4 EMfl cdl, (Vfi cdc lo<u s£l d
•rang ibdi cCTng
<l5ciiin ttn»
16 16 6 6 - 1 2
1 2
IX> cKfc l(%\ nhlTt cfiii jiuil <iriL-
1:02 1QS - 11 5
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1 IS 1 IS
Mdt nguydn nhdn khdc cd lidn quan Id khi thi cdng dudng, vi^c thi cdng xdy dyng da gdy mIt I n dinh cdn bang ty nhien vln cd cua sudn doc. Mai ddc ty nhien ban ddu hodc mdi ddc nen dudng cu qua thdi gian ddi da gan dgt trgng thai cdn bing, tUdng quan giQa cdc md men giO vd md men gdy trUpt ddi vdi 1 diem ndo dd ft ra Id ngang nhau. Khi tien hdnh xdy dyng tuyIn dudng cd doan tuyIn di bdm theo dudng cu, cd dogn cdl tuyIn hodc md tuyIn mdi d l ddm bdo tieu chuIn ky thuat, hlu hit cdc trudng hpp dIu phdi md rdng nln dUdng. Song song vdi vi^c idm dUdng id vide xen din ddt 6 chdn bd die phye vy cho vide xdy dyng cdc cdng trinh ddn dyng dpc theo dUdng.
NhUng vipc ndy ddi hdi phdi ddo hododlp cdc khii dat trdn bd ddc Idm thay dli dja hinh bd ddc, Idm thay d l i sy phdn bd Ung suit trdn m$t bd die, tCf dd phdt sinh cdc khe nUl phdt triln gin song song vdi b l mdt mai ddc tao nen nhilu mdt ylu. Chfnh dpc theo eac khe nUt ndy hidn tUpng djch ehuyin ddt dd thudng xdy ra hlnh thdnh s?t Id vd syt trupt. Hi$n tupng ndy xdy ra khd nhilu trdn dudng H i Chf Minh, tidu bilu nhu vj tri Km432+130 - Km432+290, hidn tUpng syt trUdt dd xdy ra khd nghidm trpng.
2.3 Do inh hudng cda nUdc m$t vk nudc ngdm
Hogt ddng cua nudc mdt vd nude nglm ed dnh hudng rit Idn dd'n dp I n djnh cCia mdi die, gdy nhieu bat Ipi cho khd ndng chju lyc ciia mdi ddc. Khi dd't tham nudc thi trpng lupng the tfch cija khIi dit trdn bd doc se tdng len, ding thdi trgng thdi cCia ddt ehuyen tu ciJng hodc nilra ciJng sang ddo mIm, thdm chf ddo chdy, tdm gdc ma sdt trong vd eudng do lye dfnh cua dd't da gidm di dang k l . Theo nghidn cUu, vdi dd't set ed gdc ma sat trong 25° va eUdng dd lUc dfnh 0.6MPa,
khi d trgng thdi bdo hda nude thi gdc ma sdt trong (H cdn 6° - 9", lyc dfnh cdn 0.01 MPa. Hodc chi d n t I m cua ddt tdng Idn khodng 3% (25% Idn 28%) | CUdng dd lyc dfnh gidm di 1/3, tUdng ty nhu vdy, I dd I m cua ddt tdng 5% thi cudng dd lyc dfnh gidmj
m|t nCsa. * Syt trupt trdn dudng H i Chf Minh dogn qua tinl
Gia Lai - Kon Tum xly ra chCi ylu vdo mua mua, t^i trung vdo khodng thdi gian tU thdng 7 d i n thdng 1 hdng ndm, ddy Id nhOng thdng ed lupng mua cai trung binh tii 500 - 700mm/thdng. Hi^n tUpng sg trupt thudng xdy ra ddc bl$t nghidm trpng sau nhQiij trdn mUa ed cUdng dd Idn vd thdi gian kdo ddi (250- 300mm/ 3 - 4gid). Khi mUa Idn kdo ddi, Idp dit bi mdt ed nguIn gde tdn tfch, sudn tfch nhanh chdng dg din trgng thdi bdo hda, sau dd nude mua til^tgi thIm xudng cdc Idp dit dudi vdi tdc dd chdm hon Thdi gian nglm nUdc cdng kdo ddi, nudc ngdm sli vdo mdi die gdy syt trupt.
Theo thyc nghidm, tie dp thdm cOa nudc xuln{
cdc iogi dit khdc nhau nbu sau (Bdng 2):
Bing 2
T T
I 2 3 4
t ^ ^ i d S l D3'[sdi BSi »fi pha D3i cfil pha Dfl'icAr Ibb, s&icuCi
T<]cdi}turm(mm/pb) 1 Q 0 2 - Q 1 5 m Q 1 5 - a 2 2 ^ 0 J - Q4 ^ 0 4 - Q 6 7 -/m
T$i mgt s6 dogn c^u t?o mai taluy Ici 6A bj phong hda c6 nhi^u khe nirt, nudc mua ng£lm v^o d£lt da vk theo cac khe nCrt dl sau vao mai ddc, xuSt lo ra bS m^t mai d6c, c6 vj tri nudc nglm xult 1$ tai do sSu 1- 2m tinh tCf chSn mil d6c. Nudc mua nglm sau v&o mdi ddc lim gidm si:rc khdng cSt ci^a dit ddng k l din d i n sut truflt
MOt nguydn nhan lam hidn tuong sut Iruot tren dudng Hd Chi Minh doan qua tTnh Gia Lai - Kon Tum xSy ra nhldu Id h# thdng thodt nUOc cOn thidu. He thdng ranh bidn hidn tai vd h§ thdng cdng ngang sU dung Id ranh biSn dinh hlnh va mdt dO cdng tboiil nudc ngang trung binh 250m bd tri 1 cdng, theo tinh todn thi hd thdng thodt nudc ndy chi du thodt nudc cho phin luu voc bao gdm 1/2 ndn dudng dao, b4 rdng mdi taluy ndn duOng ddo khodng 6m, bd rdng til mdp taluy ndn dudng ddo vdo trong sudn nul ktioSr^
5m. Bdi vdi dudng Hd Chi Minh doan qua tinh Gia tai - Kon Tum rit nhidu doan cd taluy dudng cao til 30- 50m thi hO thdng ndy khdng du thodt nudc Idm ni/flc mua chdy trdn lan qua m$t dUOng, chdy xudng taluy dm gdy xOI Id vd lam sy.t'truot ta luy dm. Trong cdc doan thuOng xdy ra syt truot, mac dCi suOn ta luy ti\
cao til 30-50 m nhung chi cd dosn ddo Lo Xo Id a thid't kd ranh dinh (van sgt trUOt vl ohua hoan chlnh), ode doan khdc hlu nhu khdng thidt ke ranh dinh dSn ddn nudc mua nglm vao mdi taluy v4 chdy trdn Jan trdn mdi taluy gdy mat dn djnh. Boan Km354-f6pfc Km354-i-720, mdc du da cd ranh dinh nhung hi^n tuOng syt truot v5n xdy ra vl ranh dinh bd tri khdng di tidt didn vd vi tri ohua thuc su hop IJ.
Ngoai vide Idm tang dd I m , Idm gidm cac djl
trung cd hoc cOa dit da, nudc nglm cdn dnh hudris
Tap chf GTVT 5/2012
^9
i l n dp I n djnh cua bd ddc tren phUdng dien dp lyc huy tTnh (nudc trong cdc khe nuft, l6 rong,...) hodc dp i/c thCiy ddng (idm thay doi dp lye ngang cCia nudc rdn cdc bd ddc ngdp nude,...), chung d I u lam gidm chd ndng chju lyc ci^a bd d i e .
Thyc te dnh hudng eCia dp lyc thCiy tTnh v d dp lyc huy ddng doi vdi s y on djnh mdi taluy eCia cdc mdi Joe taluy dUdng trdn dUdng H i Chi Minh chua cd s l idu t h i n g kd cu t h i . Myc nudc n g l m trdn mdi taluy hudng n l m d dp sau khodng 10-15m, ed ndi len d i n
>5m, nUdc mua chij yeu n g l m vdo t i n g phu, m i l lidn i d giOa nude mUa vd nudc n g l m vl t h i rdt it vd khd (dc djnh.
3. Mpt s d gidi phap x ^ ly
De hgn che t h I p n h l t hidn tupng syt, trupt trdn audng H i Chf Minh, ed the dp d y n g cdc gidi phdp :dng nghp nhu sau:
3.1 Bl$n phkp bao v$ bd m$t mki ddc chdng xdi Id - Gia e l b l mdt mdi d i e
3ang da hdc x i p khan hodc dd ide xdy;
- Gia e l be mdt mdi d i e sang khung bd tdng cdt thep
t i t hpp vdi dd hoc xay, dd hdc ff,„^ 4, Q,^ ^g^^, ,^
<ep khan hodc trong ed; my b^ng khung BTCT - Gia ed b l mdt mdi d i e
Dang t i m be tdng kin hodc be tdng hd t r i n g c d ; - Gia c l b l mat mdi d i e b i n g ludi thdp phun be tdng;
- Gia CO be mat mdi ddc bang trong ed (cd bdn dia node ed vetiver);
- Gia ed be mat mdi ddc bang ludi Enkamat k i t Idp vdi t r I n g ed.
3.2 Bi$n phap thiet idp mdt cit hinh hgc htfp If - Thay d l i (giam) dp ddc ta luy n l n dao phu hpp /di d i l u kidn dja chat (Bdng 4.2 vd 4.3).
- C i t cd, gidm t i l mai ddc.
3.3. Bl$n phap thokt nUdc
- Xdy dyng thdm cdc cdng trinh thodt nudc mat nhu:
^anh d?nh, ranh doc, bdc nudc, ddc nude, mUdng t h I m , anh thIm, t i n g Ipc ngupc sau lung tUdng chan, mUPng Jan nude ra khdi khu vyc syt trupt;
^ - Tdng cUdng hd thdng thodt nude ngang dUdng cong qua dUdng).
- Chpn cdc loai cdng trinh thodt nude hpp ly.
- Thodt nude n g l m : Day la mdt bi$n phap quan rpng d l gidm dp Ipc nude thuj' tTnh vd Vnu^ ddng tde Jung vdo khdi dat da, tdng dp b i n chdng cat cua d i t Ja. De thodt nudc n g l m , thudng si!f dyng ranh thdm 'a dng thodt nude ngang.
Bing 3. Tri sdcho phdp t^o ddc ddi vdi mdi ddc dat
Bing 4. Tri sd cho phdp t^o ddc ddi vdi mki ddc dk
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O i l t n chD p l i ^ IBD ddc (ty le eta — r^ng) H < B i n
1 : 0 — 1:0.10
I ' O . I J — 1 : 0 , 2 S 1: 0 , 2 s — 1 - 0 , 5 0
1 0 73 1 1 00 It 1.00—1' 1.35 1 : 1 . 2 5 — 1 : 1 , 7 5
S m £ H < ISm 1 : 0 , 1 0 - . 1 ; 0 , 1 S
1 - 0 . 2 5 — I ; 0,50 1 ; 0 , 3 0 — 1 : 0 . 7 3
!• 0 7 3 — M O O 1 1 0 0 I ' l Z S
!• 1.25—1:1.30 15m<H< 23m 1 0 . 1 5 — 1 : 0 . 2 3
1 : 0 , 2 5 - 1 : 0 , 3 5 1:0.35—1 0,50
G l i Hi cho phtp US ddc phll d n cil v i o g d c nghitng cflt ih^ nj nhien it l i c itinh
Gli m cho ph«p tao dfic (If It CE M i l <li6c cao < 5tn Mdi dSc
1:1 JO —1:1,73
Git Of cho pUp UO ddc pbai cin cU vio gOc nglii (gdc cb£0 ciia IbJ ni nhien dj xdc dinh
3.4 Bidn phkp sUdung ckc kdt cdu cMu luc gia cudng - TUdng c h i n ; Tudng rp da (rp dd mg kem, rp dd mg kdm bpc nhya PVC, rp dd neo mg kem boc nhya PVC), tudng da hpe xdy vOfa xi mdng, tudng bd tdng xi mdng, tudng bd tdng cdt thep, tudng bd tdng cot thep mdng cpc (mdng cpc thdp, cpc khoan nhdi);
- Tudng dp mdi, tUdng do bang dd hOc xdy vOa xi mdng ho$e bd tdng xi mdng;
- Neo: Thanh neo thudng, thanh neo Ung s u i t trudc, cdp neo Ung sud't trudc (cdng nghd neo OVM- Trung Qud'c).
3.5 Ckc bi$n phdp ky thudt khkc - Cdl tuyen tranh xa vung dat sut;
- Xdy dyng c l u cgn, cau vUdt, ham.
4. K i t luan
- Viee nghidn cUu xi!f \y hien tUpng syt, trupt tren dudng H i Chi Minh ndi chung vd dogn qua khu vyc tinh Gia Lai - Kon Tum ndi rieng Id r i t e l n t h i l t d l dap ling ydu cau thdng xe xuydn s u i t cua tuyen dudng tQ Bac den Nam, gidm tdi cho tuyen QL1A hien t ^ i , nhat Id vdo nhiJng mua mua bdo. Tong k i t cdc hipn tupng dat syt vd bidn phdp xCr ly d khu vyc nay la mdt viec lam ed y nghTa thiet thyc. K i t qud tdng k i t ndy se djnh hudng cho cdng tdc t h i l t k l d l tang hidu qud kinh t l ky thudt cCia bidn phdp xif ly dupc lya chpn, cung nhU djnh hUdng cho ChCi dau tU trong cdng tde lya chpn gidi phdp xi!f 1]^ cdc hidn tupng syt, trupt ndy.
- Trdn dudng Hd Chf Minh, dogn qua khu vyc t?nh Gia Lai - Kon Tum, n l u gdp dgng dia hlnh cd gdc ddc ty nhidn thodi, dat nen d i n g nhat vd ed cdc chf tidu cd ly t h I p c i n lUu y d i n hidn tUdng trupt dat keo theo.
Khi dd d l ddm bdo on djnh khdng ndn xdm phgm chdn mdi ddc, trUdng hpp bat budc thi phdi nghien cUu bipn phdp gia cd ngay G
Tai l i | u t h a m khdo
[1]. IDI Daik LA (1919), Mti img ill ii. NX9 Glio ibOu vai t i l . [Z]. VM t i l c l i i i M Irfc (Mnrii Sfe Iln «k} (ZNI), * v Dwi A*/
i$a8i:mmnnim.
[31. Vlfli lieu cbD^B Alb iHlTc ( g m g l o c N i l , V i COig Ngi, l l i i y f i i Chlnh 941 ijch) (2D98), ma eiaia iUffe nm aSt vA eie vil lien iif aae Ei gla cifiBg (ei cS't) BS8BB8:I93§, NX9 Xfly difni.
[4]. 9iriB kd tBE bhu bK H cbiyii m i CBDI qbt H i n cblM » l trtfl MHgHaJMhib(19/ZiiZ), TiltHe§nimHm§afntfttr0tiil^
ESmim, lOiaifeildiiilyiinigUhaiB- TravWie.
