SCIENCE & TECHNOIOCV »E»EtOHIIENT, Hll.18, N0.K2 - 2 0 1 5
Danh gia ap lire dat len 6ng chon sau va kha nang 6n dinh trong moi trucmg xung quanh theo didu kien thi cong
• Bui Tripang San
Tm-ffng Dai hoc Bach khoa, DHQG-HCM
(Bai nhdn ngdy IJ thdng 10 nam 2014. hodn chinh sira chua nj
TOM TAT
Ap luc ddt len cong Irinh dng chon sdu phv thuQc vdo logi dat. hinh dgng vd kich Ihudc cdng irinh. do sdu. hinh dgng vd kich thudc ho mdng vd cdc tdc nhdn khde nhu tdi trgng ngodi, muc nuac ngdm. Tren ca so chgn lua. sd sung sa do linh vd chuang Irinh tinh lodn ty: ihiet lap. lien hdnh phdn tich ddnh gid dp luc ddt len cdng trinh dng chdn sdu theo dieu kien tht cong thuc te Ddi v&i cong trinh dugc thi cdng bdng phuang phdp ddo hd. cdn thiel chgn lua do sdu chon hgp ly tren co sd dg sdu chdn md tir do trd
Tif khda: dp luc ddt. ong chdn sdu, dn dmh. cdng trinh ngdm.
1 PHirONG PHAP THI CONG VA DANH GIA AP LI/C DAT LEN 6 N G NGAM
di. dnh hirdng cua dp luc ddt tha)' doi khong ddng ke Viec thay mgt phdn vdt lieu rai bdng ddt dinh gidm ddng ke dp luc ddt len vd cong trinh. Ngodi ra, viec ddnh gid mirc do liep cdn Irang thai gidl han Irong mditrudng xung quanh cdng Irinh Irong qud ir'inh thi cdng ddo kin con cho phep phdn tich khd ndng dn dinh Irong moi Irudng dia chdt khde nhau thong qua su xudt hien viing bien dang deo. Ket qud nghien cwuco ich cho vice tinh todn. bo Iri cdng Irinh hgp If vdt dieu kien thuc te.
Ton tgi hai phuong phdp co bdn Id ddo hd vd dao kin. Phuong phap dao hd thudng dp dung cho cong frinh ddt ndng. Tir mat ddt, tifin hanh ddo hd cd vdch xien ty nhifin theo khd ndng dn dinh mdi doc hodc vdch thdng dung vdi he ih&ig chong vach. Sau dd, tifin hdnh xay dyng kfit cau ngdm rdi lap ddt, khdi phyc mdt bdng dfin cao dp tu nhifin hodc xdy dyng nhihig cdng frinh frfin mat nhu dudng xd, nhd cua [3]. Phuang phdp dao kin bao gom dao dudi ndp va khien ddo hay kich ddy.
Phuong phdp dao dudi ndp Id ldm ndp frirdc roi mdi ddo ddt. Phuang phap nay dugc tien hinh bdng cdch ldp dam thep che chdng ho dao, lat mat dudng dfi dam bdo giao thdng frfin m$t dat Phuang phap khifin dao la phuang phdp thi cong CO gidi dimg khifin dao dudng ham ngdm dudi mat ddt.
Khi Ihi cdng he thdng cdng frinh ngdm nhu h i m did, hdm cho ngudi di bg, ham kT thugt hay cdc cdng frinh cdp thoat nudc ddt khdng qud sau bfin dudi nhimg cong frinh frfin mat, phuong phap ddo lg thifin hay khifin ddo cd thfi gay lun cdng
TPHI 84
TAP CHi PHAT THEN KH&CN, TAP 18, gOK2-2C15 frinh fren mdt do bifin dang ciia khoi dat da xung
quanh. Trong trudng hgp nay, phuong phdp ddy ep (hay phuong phdp kich ddy) dugc xem la phii hgp vdi nhQng difiu kifin rdng bugc frong khu vyc do thi.
Cdc nhifin cuu ly thuyet ve dp lyc dat len cdng frinh ngdm theo mdt sd tdi lieu co Ihfi phan ldm cdc hudng sau [1], [2], [3], [4]: Hudng Ihu nhdt: gid thifit mdi frudng dat da xung quanh cdng frinh Id rdi rac vd su dyng co sd ly thuyet sire ben vgt lieu de tinh loan. Day la nhung cdng frinh nghien cuu dp luc dat khong xet dfin sy lam viec tuong ho ciia khdi dia tdng. dya fren cdc so lieu thyc tfi va nhung gia thiet rifing ciing vdi vific su dung cdc phuong phap tinh gdn diing nhu cac gia thifit tao vdm cua M.M.E^rolodiakonov va mdt sd ngudi khde, gid thifit vfi cac ldng thfi frugl d ben vdch hang, cdc gi thifit dya frfin quan sdt thyc te cung nhu cdc gi thifit dya frfin viec su dyng ly ihuyfit dan hdi vd co hpc ket cdu. Hudng thir hai: gid thiet mdi frudng ddt da Id lifin Iyc, dan hdi va diing ca sd ly thuyet dan hdi vd ly thuyfit deo de tinh todn. Ngudi ddt nfin mdng cho hudng nay vao ndm 1938 la R.
Phenher.
Theo gid thifit cua nhd dia chat A. Heim, dp lyc do frgng lugng cdt dat co chieu cao bdng ch ifiu sdu dgt cdng frinh tdc dyng Ifin vdm cdng frinh ngam cd gid frj: p=yH. Trong do: y - frgng lugng rifing ciia dat; H - chieu sdu tir mgt dat dfin dinh cdng frinh.
Day Id gta thifit dan gian va do dd chi dp dung cho trudng hgp ham dat frong dat bdo hda nudc, khi dp lyc ddt gan nhu dp lyc thuy iTnh hodc khi cdng frinh d$t rat ndng. Trong hdu het cac trudng hgp khde, dp lyc tinh theo gid ihifil ndy cho ket qua Idn hon thyc tfi rdt nhifiu. Thyc vgy, do hifiu img vdm vd tuang tdc vdi khdi ddt da kfi can nfin dp lyc (hyc te tdc dyng len ndc cdng frinh ngdm cd gid tri
be han dang kfi so vdi gia fri ung sudt do xrong lupng bdn than cpt ddt.
Phorkhemier chdp nhdn rdng dp lyc bdng cpt dat dang Idng try thdng dung cd day tya len ndc cong frinh. Khi dd, frong lugng cpt dat bi giam yeu do luc ma sdt phdt sinh frfin cdc mat phdng frugt thang dung. Ddng vdi quan diem tinh todn nay la Birbauner khi xem dp lyc len cmig frinh la do mdt khdi dgng nfim. Ngodi ra, cdn cd gid thiet dya fren nguyfin Idc tyt cgt dia Idng dugc nghifin cuu bdi Zanxen va Ketler.
2. DANH GIA AP L^TC D A T LEN C 6 N G T R I N H CHON SAU KHI T H I C 6 N G BANC PHUO>*G P H A P D A O HCK
Dgc frung cho cac phuang phdp linh loan ap Iyc dat len cdng frhih khi dao h d dugc thifit lap bdi K. Terzaghi [3] va so dd ap Iyc tac dyng Ifin cdng frinh nhu hinh 1.
Bifiu thuc xac dinh dp lyc Ifin cdng frinh cd dgng:
.M
l _ e - ^ , " w ) + q j - K . n w ( , j Trong do: ai be rdng khdi trugt, a, = a + h . t g ( 4 5 ° ) ; y - t r m g lugng rifingciia ddt; Ko - hfi sd dp luc ngang, K = —^ ; c -
luc dinh; <p - gdc ma sdt frong; q - tai frgng phan z
bd fren be mdt, n = — , vdi z Id do sdu ke tir mat ai
dat dfin dinh hdm.
Tir COTg thiic (I), cd thfi thdy rdng dp lyc ddt theo phuong dung tdc dyng Iai c&ig trinh thay ddi dieo chifiu sau chdn, kich thudc c&ig frinh, ddc TPHI 65
^ 1 1
SCIEHCE & TECHIIC106Y DEVEIOPMEHT, Vlll.18, HO.KZ - 2015
trung ca ly ciia ddt ddp. Dya frfin cdng thuc ndy, cd thfi khao sat sy thay ddi dp lyc ddt theo chieu sdu khi ddp bdng cdc logi dat khde nhau.
Hlnh I. Sa do linh toan ap lyc Icn cdng trinh chon sdu theo K. Terzaghi
Ddi vdi cdc cdng frinh thi cdng bdng phuong phdp khai dao, ddt dap lai Ifin cong frinh sau khi thi cdng cd the la dat rdi ho$c dat dinh ho^c ddt ddp nhifiu Idp.
V i ^ phdn tich dp lyc Ifin vdm cdng frinh ngam chdn sau dugc thuc hien bdng chuang trinh ty thifit lap frfin CO sd cdng thuc (1). Kich Ihudc cdng Irinh tinh lodn cd bdn kinh 0,5m vdi cdc dg sau chdn khde nhau vdi cdc loai vat ligu san lip khde nhau.
(a)
(b)
Hlnh 2. Quan h? ciia dp lyc dja tang ien vdm cdng trinh ngam Oi theo dg sdu z vdi kich thudc cong trinh a
= 0.5m (hinh vuflng h = 2a = I .Om) dugc san lap; (a) bdng dat rdi co goc ma sdt trong khac nhau; (b) bing
dat dinh cd lyc dinh Idiac nhau (chu I'; az(:) Igi c = 30 KN/nr c6 gid tri biing 0) Vdi vgt ligu san lap bfin frfin Id cat khdng c6 lyc dinh, gdc ma sdt frong thay doi tii 28°, 30°, 32", 35°, 40° dfin 45°, dung frpng Y ^ = 19 KN/m^ kfit qud tinh toan d hlnh 2 cho Ihay d dg sdu ch&i b^, dp lyc dia tang Ifin cdng frinh khdng cd sy khde bi|t nhieu vdi cdc logi cdt cd gdc ma sdt frong khde nhau khi khdng xet dfin dp luc do tai frgng ngodi.
Tuy nhien, dp lyc dia tang len vdm cdng Irinh ngdm cd gid fri be han dp lyc do frgng lugng ban thdn ddt do hifiu ung vdm. Trong trudng hgp ndy, dfi dp lyc ddt tdc dyng Ifin cdng frinh thi dat phai frugt theo mdt frugt do qud frinh khai ddo hay theo mdt frugt yeu nhdt, chinh sue chdng cdt cua ban than dat Idm giam gid fri dp lyc dat tdc dyng len cdng trinh. Do dd, cang xudng sdu, img suat do frpng lugng ban than dat nfin cdng ldn, sire chdng cdt cang tang nfin dp lyc gidm ddn dfin gid frj khong doi d dd sdu gidi hgn nao do.
Cd the thdy rdng nfiu cd thanh phan lyc dinh, dp luc ddt tdc dyng Ifin cdng frinh se nhd hon. Ket qud tinh toan d i o trudng hgp san 1 ^ bdng dat dinh cd dung frgng 19KN/m^ vdi gdc ma sat frwig xem nhu k h a i g ddi (p = 16° vd lyc dinh thay ddi tir c = 10, 20 d&i 30 KN/m^ cho thdy khi khdng xfit tdi frpngngodi, vdi ai<(Y lc), gid fri Oz dugc xem bdng
TPSHtS
TAP CM PHAT TVER lOUCIi TAP 18, SO K2-Z015 0, tuc Id khdng phdt stnh dp tyc len cdng trinh.
Dieu ndy chung td viec sir dung ddt dinh Idm vdt lieu san Idp se giam dp Iyc Ifin COTg trinh ddng kfi so vdi trudng hgp mdi trudng xung quanh cdng trinh ngdm Id vat lieu rdi.
Trong thuc te thi cong cdng frbih dng chdn sdu d khu vyc Ihdnh phd Hd Chf Minh bdng phuong phdp ddo hd, vgt lieu ddt rdi thudng dugc su dung dfi san Idp mat bdng sau khi thi cong. Khi dd, do dp lyc dja tdng Idn, mpt sd mdi ndi c6 thfi bi dich chuyen, vdt lieu dat rdi diui vao dudng ngdm tiifi hifn qua sy syt lun m$t ddt cyc bg d mgt sd vi fri.
Trong nhihig trudng hgp ndy, vat l i ^ san 1 ^ can thifit phdi dugc thay the bdng vgt lieu cd thdnh phdn lyc dinh.
Khi Ihi COTg cdc cdng frinh ngdm frOTg thanh pho, ngudi ta Ihudng dung cdc ban cir thep ddng hai bfin thanh dao, sau khi Ihi cdng ldp ddt cOTg frbih xong, tien hdnh ldp dat dong thdi rui ban cir.
Khi do mdt frugt cua khoi dat se Id mat khai ddo Ihdng dung.
Theo cdc Idi l i ^ dd cd, vipc xac dinh dp Iyc len cdng frinh hau n h u kh&ig xet dfin anh hudng ciia myc nudc ngdm vd trudng hgp thi cdng lap bdng nhifiu Idp daL d khu vyc ddng bdng ven bifin, myc nudc ngam thudng xuat h i ^ khi khai ddo rat ndng cho nfin v i ^ todn tinh todn dp lyc ddt Ifin cdng trtnh ngdm cdn thiet xet den dnh hudng ciia myc n u d c n ^ t m .
S a dd bdi todn nhu hhih 3 dugc phdt trien frai ca sd ly tfiuyfit ciia Terzaghi phuc vy Iinh loan dp tyc dja tdng tfin cdng frinh ngam frOTg difiu kifin cd myc nudc ngam vd khi ddt lap nhifiu Idp.
1 1 1.1 1 1
'• M -r ••"
• ' t - - l 1 '
m^
t
il! :
fc!-.d
Hin h 3. So d5 bai toan ddt Idp nhieu lop Xel tu mdt nudc ngdm tdi mat frfin ldp d i t thir 2 (zi): h . < z < Zi, gdc tpa dp zi = 0 ddt tgi z = hw:
J", =T.z,+—^^ ^ 1 - e " + q , e ' T g i z = zi:
i
' ^ - = ' • ^ ^ ^ " ^ 1 ^ ' " •
Xet tir dp sdu z = zi tdi z = zj, liic ndy coi Oz tai z = zi Id tdi frpng ngodi q ddi vdi Idp 2, gdc tog dp zz = 0 (fit tgi z = zi, tuang Iy ta cd:
%=yj^+
K^tgft
1-e • " +q,e •'i^^J.^.-^
][,^^-'}^^-
(2)
Tp»qt7
ft TECHHOIOSY BEVELDPMEHT, V0M8, Ho.K2 - 2 0 1 5
Nhu vdy, cdng thirc frfin cho phep Ilnh dp lyc dat len cdng frinh tai do chdn sau z frong bdi todn cd myc nudc ngam vd ddt ldp nhifiu ldp.
Xfit bdi toan cu thfi vdi cdc thdng sd theo bang 1:
Bang 1. Thdng sd ddt nen fren cdng frinh 6ng
Lifp dat
1 2
Mirc niroc ngim
LtfC dfnhc (KN/m^)
30
0 Goc ' ma
16 30
Trong iirimg nfing T (KN/m')
19 19
10 Cao trinh
-4.S -5,0
-2,0
Ket qud tinh todn cho cdng trinh chdn tgi dp sau: z - 5m, bdn kinh r = 0,5m, rdnh dao rpng 2a = 3m cho gia fri Oz (z = 5m) = 9,762 KN/m-, Bdi todn tinh loan thyc hi|n frong trudng hgp nay cd -jf nghTa thyc tiai cao. Thyc vgy, xung quanh cdng frinh thi v i ^ san lap va ddm chgt dat dinh rat khd diyc hign so vdi su dyng vgt lipu rdi san lap phil qua ndc cdng frinh. Dfi hgn che dp lyc Ifin vdm cfing frinh cdn thifit su dyng vgt lipu cd lyc dinh.
Ket qua Iinh todn cho thay dp lyc Ifin cdng frinh chdn d dp sdu 5m cd gid fri khdng dang kfi o^ (z = Sm) = 9,762 KN/ml
3. PHAN BO CNG SUAT VA KHA NANG 6 N D | N H TRONG M O I T R U 6 N G DAN H 6 I XUNG QUANH CONG TRJNH DANG TRON KHI T H I CONG DAO KIN
Nghifin cuu dp lyc dia tdng thuc chdt Id xdc djnh frang thdi ung sudt cua nfin ddt frudc vd sau khi thi cdng cdng frinh ngdm. Vdi cac cdng frinh
thi cdng ddo kin, sd dyng ly \h\iyk tfnh todn img suit cda Kirsch [] c6 th^ xdc djnh dugc trj s6 iing suat tgi cdc dilm xcr.g quanh cdng frinh, tir dd xic djnh dugc vimg anh hudng xung quanh cdng trinh ngam vd mirc d$ t i ^ can gidi han cua n ^ ^ xung quanh cdng trinh. Theo 1^ thuyet dan hAi, cic thdnh phan img suit frOTg mdi irudng xung quanh cdng frinh dgng ong frdn dugc Kirsch dfi nghi xdc djnh t)iing cdc bifiu thirc sau:
Trong do: pi, p2 - ung sudt phdp Idn nhat vi nhd nhdt do frpng lugng ban thdn.
"Jr. (Te. T,e - cdc Ihdnh phan img suat theo h^ tga dg cyc.
Hinh 4. So do xac djnh img suat xung quanh cdng trinh ngam trong tga dd cyc
Trill 68
TftP CHI PHAT TMEH KH&CH, TAP 18, SO K2- 2015
u'ng suit theo phuong dijmg vd phuong ngang cd
thi xdc djnh dugc tir cdc gid frj ciia cdc thdnh phdn ung suit theo tga dO cyc nhu sau;
a , = H L ± £ l + £ L Z £ l c o s 2 e - t ^ s i n 2 e
^cos2e + T^sin2e
vi anh hudng xung quanh cdng frinh theo cac thanh phan img suat frong cac trudng hgp d vi tri bdng 5 ldn kich thudc cdng frinh.
Tir cdc gia fri ciia cdc Ihanh phan img sudt chinh Idn nhit vd bi nhdt cd thfi xdc dinh dugc muc do tiep can trang thdi gidi hgn frOTg mdi trudng dat da xung quanh cdng frinh:
(4)
sm(p(CT, +CT3 +2ccotg(p)
(6)TCr d6 cd thi xdc djnh dugc cdc gid frj img suit chfnh Idn nhit vd nhd nhit theo cdc bifiu thirc:
.=iK-
(5) Hi$n nay, vdi cdc Ihiet bj thi cdng hipn dgi, mgt so cdp ngam hay cflng frinh cip thodt nudc ngdm dugc thi cdng bdng phuong phdp khifin dao hay rd hot. Sy phdn bd dp lyc Ifin cdng frinh frong frudng hgp ndy khde bipt so vdi phuong phap dao hd. Do ddc difim dieu kipn thi cdng, frong hau h^ cdc frudng hgp, cdng frmh cd dgng hlnh frdn theo mat cdt ngang. Vipc Iinh todn cdc thdnh phdn umg suit dugc thyc hipn nhd sy irg giOp ciia cac chuong frinh tinh todn ly thifit lgp. Trong cac mdi trudng dat da khac nhau, dng suat xuyfin tam a, xung quanh cdng frUih d hdng (6 = 0°) cd khuynh hudng Idn hm d dinh (6 = 90°) vd d gdc (6 - 45°) frOTg khi ung suat tiep tuyin Oa thi ngugc lgi. Ngodi ra, dng suit tifip T,^ khdnghlnh thdnh dhdng vd d dinh md chi xuit hipn d gdc vdi gid fri Idn nhat tgi vd ham vd giam nhanh vfi phia xa cdng frinh. Phgm
(b)
Hinb 5. MiJrc dp tiep cgn tiang ttidi gidi tian xung quanh cdng trinh n g ^ dgng Iron (a = 0,5m) d dd sau 5m. (a) troi^ moi trudng dat rdi; (b) ttong mdi trudng
dat dinh.
Kfit qua tinh todn cho cdng frinh cd kich thudc (ban kinh) a = 0,5m chdn d dp sau 5m thfi h i ^ d hinh 5 (a, b) cho thay dd dn dinh frong mdi trudng dat dinh Idn hon so vdi frong moi trudng dit rdi.
Trong mdi trudng dat rdi, d pham vi kfi can cdng
T P U I 68SCIENCE ft TECHNOLOGY DEVELOPMENT, Vtl.18, No.K2 - 2015 trinh, trang thai ung suat vugt qud trgng Ihdi cdn bdng gidi han, dat cd thfi bi syp dd nfiu khdng bd fri kjp Ihdi .vd cflng trinh nhdm chong giir. TrOTg mdi trudng ddt di'nh, hd khoan cd the ty dn dinh vd khOTg can bien [rfidp chOTg giu'. Difiu tuong ty cQng dugc ghi nhan frOTg mdi frudng ddo hd.
Tir kfit qud tinh todn cd thfi Ihay rdng frong mdi trudng ddt rdi, phgm vi dat nen bi bifin dgng deo (vugt qud trang thai cdn tidng gidi ban) phat frifin sau rgng d cdc gdc cdng frinh (0 = 45", 135", 225"
vd 315°). TrOTg mdi frudng ddt dinh, vimg nguy hifim cd Ihfi cd Id d dinh vd d day cflng frinh K £ T L U ^ VA KlfcN N G H I
Tir ket qua tfnh todn bdng cac chuong trinh ty thifit lap frfin co sd cdc ly thuyet dd cd (frfin cd sd phdn mem lap trinh [rfifl bifin Id MathCad vd C#) vd bd sung sa dd tinli, cd thfi rut ra cdc kfit lugn danh gid dp Iyc dit Ifio c6ag trtnh dgng &ig c h ^ sdu nhu sau:
Ap luc dia tdng len vdm cong Irinh thi cong ddo hd:
Ap Iyc dja tdng tdng theo dp sdu chdn frong phgm vi z/d = 15 ^ 20. Tir dg sau nay frd di, dp Iyc dia tdng frOTg ddt rdi khong tang len nUa.
Ap lyc dia tang frOTg d i t rdi tdng theo dg sau chOT vd phy thugc k h m g ^ n g kfi vdo gid tri gdc ma sdt frong cua d i t
Ap luc dia tdng khi chdn cdng frinh frMg dat dinh vdi dng cd kich thudc tu Im frd Igi cdgii fri khdng dang ke hogc bdng khdng cd ddi d cdc dp sdu chdn khde nhau, cdng frinh cd Ihfi ty in dinh.
Trong trudng hgp lhi cong ddo kin:
Trong mdi trudng dat dinh xung quanh cdng frinh, dp dn dinh (the hifin thdng qua muc d5 tifip can frgng thai gidi ban) tdt ban dang kfi so vm frong mdi frudng ddt rm.
Vung nguy hifim xung quanh cdng trinh frong mdi trudng ddt rdi la d cac gdc, cdn viing nguy h ifim frong mdi trudng dit dinh Id d dinh vd day cflng frinh.
Nhu vay, mdi frudng dit dinh la mdi tnrdng phil hop dfi bd fri hogc sir dung lam vat lieu san ldp ben fren cflng frinh ngdm. San l i p cdng trinh ngdm bdng vgt lieu cdl cd thfi gay bdt Igi cho dieu kipi lam vific dn dinh cua cdng frinh, cd Ihfi lip qua cdng frinh bang cdt, cdn bfin frfin sii dyng dit logi set dam chat. Khi dd, dp lyc Ifin cdng frinh gidm di dang ke, dam bao difiu kiai dn dinh cdng frhih.
T P U I 70
T^P CHi PHAT TBIEH KHftCH, TJP 18, SO K2- 2815
Evaluation of earth pressure on buried pipes and stability of surroundings according to construction condition
• Bui Truong Son
Ho Chi IVlinh City University ofTechnology, VNU-HCiyi
A B S T R A C T
Earth pressure on buried pipes structure depends not only on soil type, shape and dimension of structure but also on depth, shape and dimension of excavated holes and other factors such as structure load, underground
water level. Based on the selected and modified computational scheme with self-established program, the earth pressure on pipe structures according lO the construction condition is evaluated and analysed. It is recommended lo choose Ihe buried depth for structure in "cut and cover " excavation method so that the influence of earth pressure is reasonably steady from ihe
buried point downward. The replacement of backfill material lo cohesive material partially can help lo reduce significantly the earth pres.iure on the buried structure. In addition, evaluation of the the degree of approaching to limit slate in surroundings n bored tunnelling excavation allows for analysing the stability in various geological conditions according lo the appearance of plastic zone. The research results are useful for calculating and arranging underground structures reasonably in actual condition
Keywords: earth pressure, buried pipes, stability, underground construction.
T A I U ? U T H A M K H A O
[1]- NguyfinQuangChifiu, Trdn Tudn Hifip Thiet ke cdng vd cdu nhd tren duang d id. NXB Giao thdng van tdi (2004).
[2]. Le Van Thudng, Dinh Xudn Bang, Nguyfin Ti&i Cudng, Phi Van Ljch. Ca so thiit ke cdng Irinh ngdm. Nhd xuat ban Khoa hgc va Ky thugt (1981).
[3]. N.A. Xutdvich. Ca hoc ddt (bdn dich), Nhd xuat tan Ndng nghifip (1987).
[4]. L. V Makdpski. Cdng trinh Ngdm Giao thdng Do lhi (ban djch). NXB Xdy dyng (2004).
[5]. Trdn Thanh Gidm, Tg Tifin Dgt. Tinh todn cong irinh ngdm. NXB Xdy dyng (2002).
Tpang 71
SCIENCE ft TECHHOLOBY BEVELOPMEHT, Vil.18, H i J Z - 2815
[6]. Nguyen Xuan Trgng. Thi cdng hdm vd cdng md hinh ddn hdi deo vdi lieu chudn phd ho^
fnn/j ngdm. NXB Xdy dyng Hd Ndi (2004). Hoek - Brown. Tgp 12 (frang 677-686), [7J. Tr5„0uangHuy.BuiTruc„,gSon.fl*av?;„ Tuyin tSp kit qua khoa hpc cong ngh« 2009,
ung sudt-bien chng cua dot nin xung quanh °"^
cong trdn chdn sdu d khu vuc Thdnh phd Ho [9]. Lee, C. J., and B.R. Wu, H.T. Chen, K.H.
Chi Mlnh. Tap chi Cau dudng Vipt Nam, sd Chiang. Tunnel stability and arching ^ecis 11, ndm 2007, frang 21- 25. during tunneling in soft clayey soil.
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dd xung quanh cdng trinh ngdm tren ca so
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