KHOA H O C - C d N G N G H |
Nghien ciru gia cuung dat yeu bang dung djch silicat-nano
• TS. N G U Y I N ANH TUAN; ThS. Ll X U A N QUANG;ThS. H O A N G THj THU Hl^N Trudng Dgi hoc Cdng nghe Giao thdng van tdi
TOW TAT: Hien nay, c6 nhieu phuong phap gia CO dat yeu: Phuong phap co hpe, phuong phap hoa hoc, phuong phap dang duoc su dung vat ly ., trong do phuang phap hoa hpe c6 nhieu uu viet, duoc sP dgng kha rpng rai tren the gioi va 6 Viet Nam. Bai bao trinh bay mpt y tudng nghien cuu ban dau ve viec gia co dat yeu bSng dung dich silicat-nano.
Til/ KHOA: Gia co dat yeu, dung dich silicat-nano ABSTRACT: At present there are many methods of soil reinforcement. Mechanical methods, chemical methods, methods are being used physics , chemical methods have many advantages, is used quite widely in the world and in Vietnam, In this paper, presented an initial idea of weak soil reinforcement with silicate-nano solution KEYWORDS: Soil reinforcement, silicate-nano solution
I.OATVANO^
1.1. Phuong phdp gia cUdng cTat da yeu bdng cac chat hoa hoc
1.1.1. Tren the gidi
Van de gia eUdng dat da yeu bang cac chat hda hpe da duoc nghien edu, l p dung trong viec xay dung cac cdng trinh ngam trong dat da yeu tai CHLB Nga va mPt sd nude khIe nhQng nam 80 the ky XX.
Khi dat da yeu, khong on dinh ed nuPe hay nen dat da CO dp rong va khe ndt nho khong trUc tiep dCing phuang phap phut vda xi mang thi eP the dung phuong phap bom chat hoa hoe de gia cudng - goi la phuong phap silicat hda.
Phuong phap silieat hPa dung thich hpp nhl't trong cac trudng hop sau day:
- Cat khd va eat bao hoa nude eo he sd tham 2 - 80 m/ngay dem;
- Cat nho va cit by! cd he sd tham 0.5 - 5 m/ngay dem;
- Mpt so a set;
Phuang phap silicat hoa Ung dung trong nen dat cd nhdng t i e dung sau:
70
- Lam t i n g k h i nang ehiu lUc eua dat nen;
- Lam giam k h i nang tham nUdc dudi cdng trinh;
- Tao nen mpt mang chSn ngan each de b i o ve mdng, ehong lai t i e dung x l m thuc cua nude ngam;
- Han che hay khac phuc dupe tinh chat lijn sut cila dat. Dae biet vdi dUdng ham, nhd gia co ma co the dao moi, do dat d l cUng nhanh; ton it mat bang, giam dupe khoi lupng thiet bi va phuong tien chdng dd, gid duoc dieu kien tU nhien tdt.
Phuong phap phut silicat vao trong dat da duoc nhieu nha khoa hpe tren the gtdt quan tam. 6 CHLB Nga, B.A.Rjanitxn da nghien edu phUOng phap silicat hoa dung cho dat cat va da co nhieu cong hien Idn trong linh vuc nay. V.V.Axkalonov da dng dung phuong phIp nay chodat hoang t h d
Phuong phIp xi mang-silie hda: La phUOng phap dung nude thijy tinh va xi mang pha che thanh hai loai dung dieh rieng re, theo mot ti le nhat djnh dung hat hole mpt may bom eP hai xi-lanh rieng biet ciing bam vao trong dat. Loai dung dich vda nay cP uu diem: VUa eo the nang cao cUdng dp cua dat nen, vda lai eo t i e dung ehong tham nude, thPi gian dong ket cua dung djch dupc khong che chinh xac.
Qua trinh sd dung cle dang dung dich hoa hoc khac nhau trong cdng nghe gia eUdng khoi than va dat da mem yeu da v l dang dugc t h d nghiem l p dung co ket qua tot trong nhieu ITnh vUc khai thae tai nguyen khoing sin, xly dung cdng trinh ngam tai nhieu nUde tren the gidi.
1.1.2. TrongnUdc
De tang cudng dp on dinh eho eae cdng trinh xay dung, khai thac tai nguyen khoing sin, thuy dien, thuy Ipi, giao thong.,, d nude ta da apdung phuong phap gia cUdng:
- Phun ep vQa xi mang, set, xi mang vdi set;
- Phuong phap neo hda gia cuPng.
Phuong phap gia cUdng bang dung dieh hPa hoc bude dau dupc nghien edu tai mot sd nOi nhU: Vien Nghien cdu KHKT MP, Khoa Cong trinh QuIn sU (nay la Vien Ky thuat cle CPng trinh dae biet).
CPng trinh nghien eUu nay da trien khai ap dyng tai mo than Tan Lap (CPng ty Than HPn Gai). Vien Nghien cdu Khoa hpe Ky thuat MP da ket hop cung vdi md tien hanh nghien cdu thd nghiem phUong phap gia cUdng dat da yeu va than b i n g dung dich hPa hoc. Dung djch
KHOAHOC-C6NGNGHE
So 10/2018
hPa hoe ap dung t h d nghiem I I dung djch ehda 68%
ureafooemandehyde. Sau khi bom xong dung dich, trang thai ca hpe - cau triic khdi than dupe eli thien dang ke.
Siliclt-nano hda la phuong phap gia cudng dat da nhP cac chat hoa hoc b i n g clch dUa ehung vao trong dat da qua cle 16 khoan {voi bom ep) dudi t i e dung cua l p luc hay t u trpng, ItJc dau I I thuy tinh IPng, sau do la elorua canxi va khoang vat na-nP (bui IP cao, tro bay). Sau phan ijmg hPa hpe tao ra gen axit silie (Creme) lien ket cac hat dat d l vdi nhau lam cho khdi dat da cd do ben cao va eP kha nIng kin nude.
Hien nay, viec x l y dUng cle ePng trinh ngam noi ehung, cong trinh ham ndi rieng dang dupe phat trien vdi toe dp v l quy mo Idn c l trong quan dpi va trong nen kinh te qudc d i n . Trong so cle ePng trinh ham dP ngoai cac cPng trinh ngam trong da cd nhieu ham trong dat, viec thi cong elc eong trinh nay gap rat nhieu khP khan do dat yeu, mUe nude ngam, nhieu eho dpng nude thudng xuyen... can cd g i l i phap ehong dd hay gia ed trUdc khi dao ham, dn dinh eua dat da va nude ngam...
Si!rdung hon hpp silicat-nano de gia eudng dat da tuy khPng mdi, nhung thanh phan cle chat cd trong hon hpp sllica-nano de lam tang tac dung cua no vpi moi loai dat d l khIc nhau van con la mpt an sd ehua cP Idi g i l i thda d i n g .
2. CAC C H A T OUaC S(f DUNG TRONG THf N G H I E M V A PHl/ONG PH A P T R O N
2.1. Cdc chdt 6MZ sit dung trong hon htfp - Nano-tro bay nhiet dien, (T);
- Bui IP nhiet dien, (B);
-XimangPCB30,(X);
-Thuy tinh Idng (Liquid Sodium Silieate,),{S): Mua tai Nha m I y Gang thepThIi Nguyen.
Hinh 2.1: Hlnh inh cac chit duoc su dung trong thi nghi
Dat (D) dupc sd dung trong thi nghiem la a cat, trang t h I i rdi rae, lay tai ePng trinh chp Pho Yen, tinh Thli Nguyen, co g =14.56 kN/m^; E = 50MPa; j = 23 dp; e ^ 0.1 MPa. Mpt sd chi tieu eo ly khac dupc Udc tinh thpng qua phan mem Roclab.
Ngudn nUde (N) sd dung d i m b i o cle tieu ehuan tuong t u nhu nUde pha tron be tdng va vCfa x l y dUng theo TCVN 4314:2003; TCVN 7570:2006.
2.2. M l u , phaong phap pha tr6n che tao mau vd mot so dieu kien thi nghiem
- Sd dung mau che tao vda, kich thude 40x40x160mm;
- Phuong phap tron: Thu ePng;
- Nhiet dd thi nghiem: Nhiet dp phong;
- ThPi gian tien hanh thi nghiem: 5/2017.
Bing 2.1. Che tao miu va ket qui thi nghiem
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Hinh 2.2- Mdt so hinh inh ve n Dien gidi:
- Mau 1: D + S - Khdng hinh thanh cuPng dp;
- M a u 2 : D + T + S = DatgiaeUdng khPng s d d u n g xi mang;
- Mau 3:0 -H S -H N = Khdng hinh thanh cUdng do;
- Mau 4: D + X -H N = Dat gia cUPng xi mang khong sddung nano;
71
KHOA HOC-CdNG NGHg
- Mau 5: D + X + N -I- T25 - Dat gia cUdng cd 25%
nano, khong dung silieat;
- Mau 6: D -H X -H N + T30 = Oat gia cUdng cd 30%
nano, khPng dung silicat;
- Mau 7: N30 -H X -i- D -HT30 = Tang nUde them 30%
so vdi mau 6. Cudng dp hon hop sau 7 ngay eo xu hudng giam, Muc dieh ehi de thuan Ipi cho thi ePng {de bOm);
- Mau 8: N60 + X -i-D-(-T30 =Tang nUde them 60% so vdi mau 6. Mae du thuan Ipi eho thi cPng (de bom) nhUng la vP nghTa vi cudng do hon hop sau 7 ngay kha nho va khong thay tang;
- Hon hpp N + X + D-t-T + Sco eudng dp tang khPng nhieusovdihonhppD-t-X-nN-i'T, [1].
- Hon hop CO thanh phan B khPng ddng rin dupe vi B CO phdn dng vdi X, tao ra mpt chat khac.
3. VI DU D A N H G I A H I £ U Q U A G I A C6 Sd dung ket q u i thi nghiem va sd dung phan mem Roclab, Phase 2 de tinh t o l n mpt so chi tieu eo b i n eua dat trUdc va sau gia cudng.
Vi du: Khio sit ham dOn rpng 10926m, cao 12077m, chieu cao cot dja chat tae dpng len dinh ham va cle kich thude khac cCing nhu dieu kien bien cua tam co khoang ham, dupe mo t l nhu Hinh 3.1. Dat trUde gia eudng la a eat, trang t h l i rPi rac, cp mpt sd tinh chat eO ly duoc Udc tinh theo Roclab. Dat sau gia eUdng: Sd dung mau 5. Cac thong sd khacdUrtc ^^i- dinh qua Rodab"I cac bieu t^Uc qua" ^e r3]
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Hinh 3.1: Md hinh tfnh toin (cic kft^ thuoc tren hinh ve tinh bing m) Mpt so ket qua nghien cUu, theo mP hinh Morh- Coulomb duoc the hien trong cac bang sau:
Bing 3.1. Ket qui tinh sigma 7 bing chuong trinh Phase 2 Chi tieu
'JLJl
Pho ling suat I Sigma 1 cua dat
mau 5
72
G i a trj s i g m a 1 X
95.270 99.106 102.942 106.206 106.628 105.545 102.888 99.173 95.761 93.808 93.366 94.889
Y
97.832 97.832 97.832 99.067 102.854 106.507 109.189 109.846 108.233 104.980 101.195 97.908
c u a d a t n g u y e n t r a n g D i s t a n c e
[ m l 0.000 3.836 7.572 11.162 14.973 18.783 22.558 26.331 30.105 33.899 3 7 7 1 0 4 1 . 3 3 3
S i g m a O n e [ M P a l 15.772
8.108 17.370 55.973 29.289 17.084 14.628 26.232 38.698 37.251 29.178 18.650
Gia t r i s i g m a 1 ciJa d a t m a u 5 X
95.270 99.106 102.942 106.206 106.628 105.545 102.888 99.173 95.761 93.808 93.366 94.889
Y
97.832 97.832 97.832 99.067 102.854 106.507 109.189 109.846 108.233 104.980 101.195 97.908
Distance [ m l 0.000 3.836 7.672 11.162 14.973 18.783 22.558 26.331 30.105 33.899 37.710 41.333
Sigma One (MPal 14.986 6.128 14.745 56.038 32.414 19.823 13.970 23.132 36.955 38.758 32.570 1 8 7 3 4 Bing 3.2. Ket qui tinh ehuyen vi ngang
bang chuong trinh Phase 2
Ph6chuyen
cCia dat
nguyen trang S U L
Phochuyen vj ngang ciia
I dat m l u 5
y
Gia trj chuyen vj ngang cua dat nguyen trang X
95.270 99,106 102.942 105.206 106.628 105.545 102,888 99,173 95,761 93.808 93.366 94.889
Y
97.832 97,832 97.832 99.067 102.854 106.507 109.189 109,846 108,233 104,980 101.195 97.908
D i s t a n c e [ m ] 0.000 3.836 7.672 11.162 14.973 18 783 22,558 26.331 30,105 33.899 37.710 41.333
Horizontal Displacement[m]
0.047 0,049 0.046 -0.004 -0,045 -0,058 -0.047 -0.021 0.013 0.042 0.057 0.048
KHOA H O C - C 6 N G N G H |
So 10/2018
Gia t r i chuyen X
95.270 99.106 102.942 106.206 106.628 105.545 102.888 99.173 95.761 93.808 93.366 94.889
Y 97.832 97.832 97.832 99.067 102.854 106.507 109.189 109.846 108,233 104.980 101.195 97.908
vi ngang cua dat mau 5 Distance
[ m l 0.000 3.836 7.672 11.162 14.973 18.783 22.558 26.331 30.105 33.899 37.710 41.333
Horizontal Dispiacementlm]
0.019 0.020 0.020 -0.001 -0.018 -0.023 -0.019 -0.009 0.005 0.017 0.023 0.019 Horizontal Displacement
Dd thj 3.1: Chuyen vi ngang eua dat nguyen trang Horizontal Displacement
- Han che viing I n h hudng den eong trinh lan can;
- Kiem soat dugc mdc do I n h hudng vieh ham va x l c dinh pham vi thi cPng hieu qua hOn.
Mae du chi dil/ng d viec nghien cdu chat gia cudng eho mpt loai dat ( I cit), sd lupng mau thi nghiem ePn ft;
vat lieu nano d day mdi ehi xet den tro nhiet dien; cac ehi ti^u CO ly ciJa dat nguyen trang, ci^ia hon hpp chat gia eudng va cija dat da dupe gia cudng ehua nghien cUu thau dao va khai thIe triet de; ehua xac djnh duoc thdi gian cd ket cua dl't d l sau khi dupe bom h6n hpp chat gia cudng. Mau dat dupe gia euPng sau 3 ngay, 7 ngay dem dl thi nghiem xac djnh thdi gian cd ket cija dat ngoli thuc te la ehua thuc sU thuyet phuc... nhUng viec si!f dung hdn hpp gia cudng dat da eho co sd ban dau ve thiet ke hon hop gia cUdng hieu q u i hon, kinh te hOn.
Tai lieu tham khdo
[1]. 0 6 NhUTrIng va eae epng si^ (2004), Nghien eUu dp dung he silicdt Idng de gia cddng khoi ddt dd xung quanh ham khi thi cdng cong trinh ngdm trong mot so loai dot dd yeu, Khoa CPng trinh Quan sU, Hpe vien Ky thuat Quan sU,Tuyen tap Bio c l o Hoi nghi khoa hoc lan thU 16, quyen 1: Cac khoa hoc ve mp. Ha Npi, 15/11.
[2]. Nguyen The PhiJng (2009), Thi cdng cong trinh ngam bang cdc phuong phdp ddc biet, NXB. Xay dung.
Ha Npi.
[3]. PhanTrudngPhiet (2010),Cahoc dot u'ng dung vd tinh todn eong trinh tren nin ddt theo trgng thdi gidi han, NXB. Xay dung, H I Not.
[4]. Nguyen Anh Tuan, Le XuIn Quang, Hoang Thi Thu Hien (2016), Nghien cUu gia cUdng khoi dat dd xung quanh dudng hdm bdng cde dung djch hda hoe silicat- nano, De tai NCKH cap TrUdng Dai hpe Cdng nghe GTVT, Ma so DTI 61730.
Ngay nhdn bai: 20/8/2018 Ngay c h i p n h | n ddng: 4/9/2018 NgU&i phdn bien: GS.TS.C>dNhuTrang
Do thj 3.2: Chuyen vi ngang eiia ddt mSu 5 Tren Bdng 3.2 va Do thj 3.1, Do thi 3.2 ehi gidi thieu ket q u i tinh gia trj sigma 1 va gia tri chuyen vj ngang va chi liet ke g i l trj ciia 12 diem dae trung nhat. Thdng qua ket qua tinh cae gia tri dng suat v l bien dang ta thay, dat xung quanh vich dUdng ham sau gia cUPng it bi bien dang han. Dieu dP la ca sd ban d i u khang djnh dugc r i n g hoan toan co the kiem solt va khdng che dUOc miJe dp anh hudng eua mai dat xung quang ham trong qua trinh thi cong.
4.KgTLUAN
Viec gia cudng d i t dci da thu hep vung bien dang deo eua dat d l xung quang duPng ham dang ke, dieu nay cd y nghia thue tien Idn trong qua trinh dao ham:
