CVv21S5702015057.pdf

LFng dung gia c6 mai ddc nen dipang bang dat tron xi mang v a i lu'di nong nghiep d Odng Thap

Improving Soft Soil To Construct A Road In-Site By Using Mixture Cenient And Waste Agricultural Net In Dong Tiiap Provincee

Ngay nhan bai: 16/11/2014 Ngay su^ bai: 16/7/2015 Ngay chap nhan dang: 21/7/2015

Tran Hung Cu'dng, Do Thanh Hai

TOMTAT

Bai bao nay trinh bay giai phap xii ly nen dat yeu (]u6i nen diidng bang cacii tron xi mSng va lUdl nong nghiep phe thai vao trong nen dat set ylu.Muc tieu la de tgn dyng nguon nguydn lieu lil6i phe thai 6 dia phUcfng va tang sulc chong cat khong thoat nu6c cua dat set yeu dUcfc tron xi mang vi \iidi nong nghiep phe thai .Tac gia tinh toan va thi nghiem vdi ham lilc?ng xi mang, ham li(i?ng lifdido am khac nhau nhSm tim ditdc m6t ham liiong s^i lildi va xi mang toi ilu cho cUcJng d6 khang cat cao nhSt.K^t qua thi nghiem cho thiy siic khang cSt c i a h6n hop dat xi mang-ltl6i n6ng nghidp ldn hdn khoang 10.9 ISn so vdi m l u dix set yeu chila xil ly va ham liic?ng toi Uu de tron vao dix l i 0.5% lii6i ciing vdi 12% xi mang.Tac gia cung da ting dung cac thong s6 c6 dU0c sau khi thi nghiem de tinh toan danh gia he s6 on dinh ciaa n^n diidng.

Tit khda: lUdi nong nghiep, site khdng cdt, 6n dinh ABSTRACT

This paper presents treatment solutions of sott soil under the road by mixed cement and waste agricultural net into the soft day. The purpose is to use local waste net materials and increase the undrained shear strength of soft clay mixed with cement and waste agricultural net. The author calculated and tested with different kinds of cement content, agricultural net content and different water to find out the optimum agricultural net and cement content which create the highest shear strength. The test results showed that the undrained shear strength of cement mixed with agricultural net larger about 10.9times than the untreated soft soil and the optimal levels to mix mto the soft soil is 0.5% agricultural net and 12% cement content. In addition, the author also applied parameters in the test to calculate the stability of the road and to rate the safety of factor to embank the road.

Keywords: agricultural net, shear strength, stability ThS. TtKn Hung CiiOng

Giang vifin, Tritcing DH Giao thdng Van tdi H6 Chi Minh Email: tranhungcuongdongthap@gmail.com Di?n thoai: 0939506819

TS. D 6 Thanh Hai {*)

Giang vign, Khoa Ky Thuat Xay Diing, TrUdng Dai Hgc Bach Khoa - Dai Hoc Qu6c Gia Tp.HCM

Email: dthai@hcmut.edu. vn Di?n tho?i: 0933 876 006

I.Gidithi^u

Trong nhiSu ngm qua, viec xay diing cac tuyen du'dng lien huyen, lign xa, vCra la cac tuyen du'dng giao thong quan trong, vila ihm nhigm cac tuy^n de ngan lu mol khi lu ve hSng neim cua cac xa huydn viing sau, vung xa ci!ia khu vifc Dong Thap MudI, ma dac biet la d cac tinh dau nguon nhii An Giang, Dong Thap 1^ v6 ciing cSn thl^t v^ cap bach.

Mot y^u di^m cCia c^c cdng trinh du'dng glao thdng d khu vUc nSy Id dUdng dUOc dip Xil dht yeu do khdng c6 dii thdi gian 34 c6 k4x nen rat de bi truot Id do tai trong bSn than, mu'a lu hSng nam...

nen can phiil duytu blo di/dng thudng xuyen.

Ben canh dd, d khu viic nay thi van de ric thSi tir ndng nghiep gia tang theo tifng nam nen viec nghien cdu xCf ly d i t dip nen du'dng sao cho cd the xd ly cac van de ve mdi trUdng vi nhanh chdng dUa vao sddung vdi gi3 th&nh hop ly mli van dim blo dp ben cdng trinh, han ch^ du'oc cic hii hdng ciia n^n dudng do dc yeu td tren 1^ rat can thiet

2. Phiftfng phip nghien cdu

Nghien cdu ca sd ly thuyet ve su hinh thanh cudng dp cUa hdn hpp dat-xi mhng va \udi,iy thuydt ve on djnh mdi ddc va sdc chong c3t khong thoat nudc cOa dSt.

Thi nghiem: Bai b i o nghidn cdu i n h hudng cua ham lUpng xi mSng, ludi doi vdi cudng dfl dat yeu thdng qua thi nghiem nen 1 true nd hdng va thf nghigm dX true tiep.Thdng qua thi nghiem ta xac dinh dupc cUdng dd khSng nen va cudng dd khang dt khflng tholt nudc cilia hdn hap dat tron xl mang va ludi.HSm lUpng xi mang sCf dung trong nghien cifu la 8% - 10% - 12%. Ham luong ludi Id 0.25% - 0.5% - 0.75% -1 % .Ham lUong nudc khi trdn w^=100% so vdi trong luong diX kh6.Ludi se dUpc cat thanh nhUng minh nhd cd ki'ch thudc 2x2 cm.

Tinh toan va md phdng:Tinh toan bSng cac cong thu'c theo ly thuyet cOa tfnh tOcin dn dinh mai ddc ciia Felienius vdi su ho trO cua phan mem Microsoft Excel v l sd dung phan mem Geo Seep va Geo Slope de tinh toan th^m v l 6n dmh cdng trinh nen dUdng.

Sau dd dua vio ket q u i tinh toan de kiem tra va

dinh g i l sU on dinh cCia nen dudng thong qua he

soan toan FS.

3. K f t q u i thf nghiem 3.1 . T h i nghifin ndn mot true nd hong

Ket q u i thi nghiem d hinh 1 cho thay cudng d p mau xi mang dat tang nhanh trong k h o i n g ham luong xi mang/dat t d 12-17%. Cudng d o mau xi mang dat doi vdi loai dat set nay tang khi ham lUong xi mang/dat tang trong k h o i n g 8-18% va g i i m khi h i m luong xi mang/dat vUpt qua 18%.

Ham luong tdi Uu cua xi mang d i i n g de x d i^ cho loai dat n l y I I 1 5 % theo trpng lUpng dat khd.

10.0 T

1 ^ 8.0

a '•J 6.0 4.0 2.0 •

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Ham lir<;nig xi maiig (%)

Hinh 1. Cucmg d6iiendancuamauxtmangdatsau28ngav

0.5% 1.0% 1.5%

Haiii iiTOiig l u c i (" o) Ifinh2 Kft q u j n ^ l true ndtifingcuamSuximangillt ham liRmg 12%xi mang CDgiaoIdng ludi

4 . Phan tfch 6 n dinh mai doc nen dircmg d i p bling vat lieu dat tr6n xi mang vdi ludi ndng nghiep

Td c i c so lieu thi nghidm da difcfc t o n g hop, ta sCf dung vao viec tinh t o i n , d i n h gia SIJ dn dinh cija cong trinh dudng d e bao kenh t d thudng thudc dia p h | n huy?n Hong Ngu, tinh D o n g Thap tjSng viec tinh toan thd

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Hlnli4. Phan tirh on dinh bang phan mem Geo Slope cong ket hpp vdi viec sd dung phan mem Geo Seep va Geo Slope theo hinh 3 va hlnh 4.

Ket q u ^ phan tich, d i n h gia he sd dn ^ n h cCia nen d u d n g thong qua he so on ^ n h thong qua viec tfnh toan t h u cdng cd k i t q u i nhd hon so vdi mfl phdng bang p h i n mem Plaxis theo ly thuydt Felienius II18,75%

doi veil dat dap la dat tU nhien va 13.21% doi vdi dat d i p dUOC gia cudng.

Ket q u i m o phdng cho thay nen dUdng dUOC d i p b i n g dat trpn xi mang va lUdi cd tinh o n dinh cao hon rat nhieu so vdi n l n dSt tU nhifin thflng qua he soan toan FS tang len 3.16 l l n n h u t r o n g b i n g l .

Bang 1. Bang tong htrp h^ so an toan FS tuVng ifng vift cac loai Bit Hip

3.2. Xic dinh h i m lUcmg t d i Uu 64 tien h^nh gia cS

&6 t i n g tinh hieu q u i kinh t e v l tan dung dUOC c i c s i n pham phe

t h i l tai chd ma v l n d^t dupc cudng dp theo yeu cau, hon hpp xi mang dat se duoc gia cudng bdi lUdi ndng nghiep da duoc cat t h l n h dang tam nhd cd kich thudc 2x2 cm theo cac h i m lupng la 0.25-0.5-0.75-1% theo trpng lupng d i t khfl.

K^t q u i thi nghigm d hinh 2 cho thSy h i m lupng ludi gia cudng vao hfin hop xi m i n g d i t vdi h i m lupng xi mang cd dinh I112% se tang trong k h o i n g 0.25-0.5% v l g i l m khi h i m luong lUdi vUOt q u i 0.5%. TU do, ham lupng ludi tdi Uu Qi gia cudng cho hdn hop xi mang d i t la 0.5% theo trpng lupng d i t khfl.

Phucmg phap FeileniuB

Bishop Janbu

Dat t^ nhien Geo- Slope

0.95 0.99 0.93

Giai tich 0.80

Dat gia cirorng Geo-Slope

3.00 2.89 3.22

Giii tich 2.65

l p lUc nen. Su gia tang so phdi vi la do dudi l p luc n^n ldn hon, t h i tich m l u giam, cac hat s i p xep g i n nhau hOn. Ket q u i cCia v i l e md phflng cho thay so phfli vi hat trUdc khi hda tan v l sau khi hfla tan, dU<^ d p t l i leOkPa, g i l m k h o i n g 15.4%. Dudi t i c dung t l i n6n, tai dp t i l 320kPa v l 640kPa, so phdi vi cOa mau d l hoa tan g i l m so vdi mSu khdng hda tan I I 1 3 , 7 % v l 12,2%. Su chgnh l i c h so phdi vj cua mau hda tan so vdi m l u khflng hoa tan g i l m khi cap t l i tang len. Mau sau hda tan cfl xu hUdng gia tang d p d n ^ n h nhieu h o n s o v d i mau khdng hoa tan khi d p t l i gia t i n g

5. Ket luan & Kien nghj 5.1 Ket luan

Ham lupng ludi trdn vao dat tdi uu 110.5% trong lupng l u d i / d l t giiip tang cUdng d p dat trdn xi mang len khoang 16%-;- 24% so vdi d i t khdng gia cUdng spi lUdi

c u d n g d o nen n d hdng cua dat trfln xi m i n g cd gia cUdng lUdi vdi h i m lupng 12% trong lUpng xi mang/d^t vh 0.5% trong lupng ludl/dat 11 8.05 kg/cm2 gan dat b i n g cUdng d d mau khdng gia cudng ludi vdi h i m iUPng 1 5 % x i m a n g / d l t l a 8 . 1 5 k 9 / c m ^

Qua thi nghiem nen mau, ta thay mau xi mang dat cd gia cUdng ludi khd bl pha hoai c i t hOn m l u khflng ludi n h d tac dung gia cudng ciia spl ludi, dat khflng co gia cUdng bi pha hoai trong k h o i n g bien dang dpc tn^C la 1 % ^ 2 % v l ddi vdi d i t co gia cUdng l u « I I : 4%^6%. ' G i l tri module E^ cua dat trdn xi mang khdng cd gia cudng lUtSI cfl quan he vdi gia trj q u tai 50% g i l t n pha hoai I I : E,, = (140-T-200)q^ va doi vdi dat trdn xi mang cd gia cudng ludi la: E^ = (SOs-l 20)q^.

Vdi loai dat tU nhien d viing Oong Thap dCing d l d i p nen dUdng cao 4m thi he sd an t o l n FS = 0.95, nen khdng dn djnh, do d d chl c6 t h ^ diing dat t u nhien d khu vUc nay d i p cho nen dUdng cao tU 3m t r d xudng.

D I t t u nhifin d viing D d n g T h i p sau khi dUOc gia cudng vdi xi mang v l ludi ndng nghiep cd the d u n g de d^p n l n dUdng cao 4m vdi hfi s6 an toan FS = 3.

Ifinh3 PhinlKtidfingtliamb^ngplilnmemGeoSeep

5 8 BBDIEdBX '•

5.2 K i l n nghj

Vific t i n d u n g cac s i n pham ludi ndng n g h i i p phe t h l i ket h p p vdi xl mang d l xCf ly d i t yfiu tai chfi d i i n g lam v^t l i | u dap d u d n g la kha t h i mang tinh hifiu qua kinh t l cao va tang cao t i n h dn dinh cho cdng t r i n h . Trong tuOng lai, d n nghifin cdu t h e m c i c y l u tfi I n h hudng den sU hlnh t h l n h cudng d p cua h o n hpp xi m i n g d i t v l ludi cung n h u c l n t i n h toan, kiem tra ddi cac cdng trinh k h i c tren pham vi rdng hon d l cd nhdng d i n h g i l chfnh x l c hOn.

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