DliN DAN KHOA HOC C O N G N G H £
MOT SO VAN DE KY THUAT NEN MONG TREN VUNG DAT DOC
PGS.TS. NGUYEN BA KE
Hpi C o h o c d d t v d Die Ky t h u q t C d n g trinh Viet Nonn (Tie'p theo)
II. DIJ BAO VA PHONG TRANH TRLfOT 1. Dir bao va theo ddi/ quan t r i e trirpt
Nhu ta da biet, nhieu vimg d nudc ta nam trong vimg khdng an toan ve trUpt, hang nam, nha't la trong miia mUa, nhieu tai bien da xay ra.
Oe de phdng va han che thiet hai phai ed eong tac dubao va dat mdc/diem theo ddi trUpt, nha't la d vimg CO nguy ed trUpt cao, viing cd anh hudng va y nghTa kinh te - xa hpi quan trpng.
Do dia hinh chia cat va kha phdc tap d nudc ta nen cong viee tren can trien khai d cac dia phuong (theo tinh hoac theo vimg lanh thd cd dia hinh tUdng tU).
1.1. Lap ban dd dubao trugt
Npi dung the hien chinh cua ban dd trupt:
- Mieu ta dieu kien dia chat, thanh / kien tao;
- Dieu kien dia hinh, dia mao;
- The n i m cua eae ldp da't da;
- Tfnh chat cd ly hoa cua da't da {dta chat cdng trinh);
- Oieu kien dia chat thuy van va khf tupng (nudc ngam, nude mat, anh hudng lupng nude mUa theo miia trong nam, ddng chay.,.);
- Sd diem trupt (qua cae vet Id) / km^
- Cac hang dpng cac td/km^;
- Kiem tra dn dinh trUpt va phan viing nguy hiem trupt.
Trong bai bao trUde (xem NgUdi Xay dung sd 212 thang 6 nam 2009) da trinh bay chi tiet each dieu tra va danh gia de lap ban dd du bao trupt cho cac tinh Mien trung,
1.2. Cach tien hanh:
- Suu tam tai lieu luu trif ve sU cd trUpt;
- Oieu tra qua phdng van (hdi dan, nha't la ngUdi cao tudi);
- Oieu tra thuc dia (do ve va khao sat dat);
- Phan tfch danh gia (cd the phai thi nghiem mo hinh hoac hien trudng);
- Bao cao thuye't minh va lap ban dd trupt.
Theo hudng dan ve edng tac khao sat [1] thi thong thudng ban dd dia hinh ed ty le 1: 50.000 va 1: 10.000 va ban dd vien tham 1: 250.000 den 1: 50.000, cdn khi phuc vu eho dU an cu the thi ban dd dia hinh cd ty le 1 : 10.000 den 1 : 2000 va ban dd vien tham cd ty 16 1 : 20.000 den 1: 6000.
Trong phan vung trUdt can ehi ra:
- Viing khong dn dmh;
- Vimg ed kha nang / tiem an trupt;
- Oua ra cac dang trUpt, dp Idn va xuat hien nguy hiem.,,.
Cd the xem dd la ban dd de du bao tai bien trUpt, dUa vao day de lap ban dd qui hoach, bd tri eae diem dan eu, khu eong nghiep, diem du lich va canh tac v,v,,.
Vf du tinh Lao Cai da xay dung ban dd trupt cho tinh minh nhu trinh bay tren hinh 1 (theo [2]).
Hinh 1. Sa do phan bo do doc dia hinh tinh Lao Cai
1.Dod6c3-ff' (2,3% dien ticti); 4. Bo doc 25 - 35° (32,5% dien tich);
2. Do doc 8-15' (18.5% dien tiet)); 5. Do doc > 35" (8,6% dien ticti) 3. Op doc 15- 25' (38,1% dien ticti);
Kiem tra va dU bao trUpt d dia ban tinh Lao Cai chdng td vdi gdc nghieng cua mai ddc tu nhien ngay d trang thai bao hoa nudc deu luon dn dinh (he sd an
ai Khd'i ITvai ihu nhal h) Khd'i mipJ ihit hai
Hinh 2. Ket qua tinh toan kiem tra tmat tai Mong sen (a) va tai km 8+100 Saps - Lao Cai (b)
1. Dta hinh thi/c te (sau khi targt): 2 Dia hinh ban diu (du doin);
3. Vich ciia mSt tnrgt thuc te; 4. MSt tn/at tinh toin: 5. Cac khe nirt (rong 5 - 10cm. sau 5- 50cm).
N G U d l X A Y D I / N G s d T H A N G 7 - 2 0 0 9
MdT sd
VANoi KY
THUAT N J NMONO.,
toan chdng trupt 1^ 1,10 -1,20). Ddi vdi mai doc co dp nghieng 30° - 40°, d trang thai tU nhien vdi mat trUpt nguy hiem nha't van dn dinh (he sd an toan 1,25 - 1,38) nhung khi bao hoa nude do mUa thi khdng dn dinh, he sd an toan ndi tren chi edn 0,73 - 0,75.
Tren cd sd khao sat hien trUdng va tinh toan kiem tra trupt d nhieu diem, da ehi ra vimg nguy hiem vi du tai Mdng Sen (xa Trung Chai, huyen Sapa) va tai km 8 + 100 tren tuyen dudng Sapa thi xa Lao Cai nhU trinh bay tren hinh 2.
0 nhung viing tiem a'n nguy hiem cung cd nhCmg dU bao trupt, vi du nhU vimg gan cau Mong Sen tuy theo cac tac dpng ngay cang xau lam eho kha nang trupt cd the td bae I den bae IV nhu trinh bay tren hinh 3.
1
t
1
Oicao
^
100-110 m
'
70-80 m 2.
'
\ v 10 0 10 20 m III \ v
30-35 m
'
'e-iom ^ \ JHinh 3. Du bao khoi truqt 4 bae d gan cau Mong Sen
1. Vach cua mat tn/at quan sM ngoai tht/c dia; 2. Mat tn/at du bao:
I, II, III, IV. Cac bae trugt
2. Quan trac trUdt
Muc dich eua quan trac la de canh bao sdm nhi/ng tai bien nguy hiem do trupt gay ra nham tranh hoac han che thiet hai. Vi tri va sd thdng sd can do de dat he thdng quan trac la can cd vao hau qua ve kinh te - ky thuat - xa hdi khi xay ra trupt de quye't dinh. Vi du d dap thuy dien Hoa Binh, tai ddi Ong Tupng, da bat dau thd nghiem dat he thdng do nay. 6 cac nude phat trien (vf du Thuy Oien) hp cd he thdng quan trac hoan hao cd kha nang truyen cac tin hieu can quan trie qua ve tinh ve trung tam xd ly va phat lenh canh bao,
Npi dung quan trac thudng (xem hinh 4) gdm ed:
a) Trac dia lase (laser geodimeter);
g) Oudng chuan dinh vi (convergence meter);
h) Oo img suat (strain meters);
He thdng nay dupe ndi vdi he thdng bao dpng. Do bien dang phfa dudi mat da't can lip:
L) Thiet bi do nghieng (inclinometer);
Hinh 4. Bo tri cac diem va loai quan trac tren mai dat de mat on dinh (Theo [3])
Hinh 5: Thiet bi do nghieng
n) Dung eu do cat - trupt (shear - strip indicator);
q) Dung cu do sU truyen am (acoustical emissions device);
r) Oo ap lue nUdc lo rong (piezometer);
Cae dung cu va thiet bi do vda neu dupc dat vao cac Id khoan va chen lap vat lieu theo yeu cau cua timg loai.
Tren hinh 4 trinh bay each bd tri cac thiet bi quan trie d mai dec cd the bi mat dn dinh.
Trdng cac Idai thiet bi tren thi chi it phai dimg thiet bi do nghieng de biet sU chuyen vi ngang cua da't.
Hinh 5 gidi thieu hinh anh va each l i p thiet bi do nghieng (inclincmeter) d mai ddc.
Vi du: Vao nam 2003 xay ra hien tupng trUpt Id da't da de doa cung dien Huaqing d thanh phd Tay An
M 4 i I n / d l li'dn
/theo tuyi'n
Hinh 6: Mat bang viing doe tn/at a niii Lishan va dudng bien dang dai
Trung Qude [3]. Cung dien nay dUdc
xay dung td ddi nha Oudng (618 -
907), nim phia dUdi chan niii Lishan
da cd nhi/ng bien dang nhin tha'y
bang mit, cd the xay ra trUdt Id da
vdi dien ldn. Viing nay lai chiu
nhCmg hoat ddng dpng dat va dang
bi liin do hut nudc ngam manh. Oieu
kien dia chat ndi chung la ldp dat
NGl/dl X A Y Dl/NG s d THANG 7 • 2009
MdT sd
V A N D ^ K Y T H U A T N ^ NMONG...
GPS
f\ ^r
Dt> thuyen \ i c i l ^ .1 chi'Cu Ttuui hi Jo (3D-SDM) b"j'n dang i l i :
OPS
Dai hiH; Kyuii. UPRI
Hinh 7. He thong quan trie ti/ dong ve tn/ai a chan nui Lishan
ho^ng tho phu len tang da.
D u bao cd the xay ra 3 khdi trupt (block 1, 2, 3) nhu tren hinh 6
B i t dau nghien cifu va quan t r i e t d nam 1991 giua Vien phdng ngda tai bien (Disaster Prevention Institute) eua trudng Oai hpe Kyoto Nhat Ban vdi ehinh quyen thanh phd Tay An, He thdng quan t r i e tU dpng da dupe l i p dat nhu hinh 7, trong do ed thiet bi do bien dang tuyen ngan - dai han (dUdng A va B tren hinh 6), tram kiem sdat chung, GPS, thiet bi dc nghieng, may ghi dia chan. Sd lieu do dupc truyen dinh ky tdi trudng Oai hpe Kyoto qua ve tinh.
Khi can quan t r i e nhung tai bien dia chat khac thi can cd nhung yeu eau r i e n g . •
(Cdn nCfa) Tai lieu tham khao
1. Nguyin Oai, Nguyen Chinh Bai - Cac giai phap chong sut Id dat da tren dudng NXB Giao thong Van tai. Ha Noi, 2001.
2. Do Dinh Dire - Hien tupng dat trupt ci tinh Lao cai.
Inter. Conference on "Management of the Land and Water resourse" MLWR, Oct. 20-22, 2001, Hanoi, Viet nam.
3. R.E Hunt-Geotechnical Engineering Investigation Handbook. Second Edition. CRC Press, Taylor & Francis Group, 2005.
"QUAN LY VA DAU Tl/ XAY Dl/NG CONG TRJNH NGAM DO THI"
N
gay 15/7/2009 tai khach san Melia Ha Noi, Cong ty APAVE Viet Nam & Dong Nam A dagc su bao tro ciia Bo xay di/ng da to chirc cupc hpi thao nay Tham du hoi thao CO Thir trudng Bp Xay dung Cao Lai Quang, lanh dao cac Cue Vu, Vien Nghien ciru, trudng dai hpe ciia cac Bp: Xay di/ng, Giao thong- Van tai, Ke hoach - Oau tu. Van phong Chinh phii, cac hpi nghe nghiep,.. va ddng dao cac chuyen gia trong nudc va nudc ngoai.ti nudc ta, viec xay dung he thong cdng trinh dd thi tren nen do thi san co se gap phai rat nhieu kho khan, dac biet la viec thiet ke long ghep cac cong trinh ngam vol cac cong trinh hien CO nham giai phong cac cdng trinh phu trp tren mat da't de khai thac, nang cao gia tri dat dai do thi. Day la mot van de con mdi khong chi vdi cac co quan quan ly nha nudc, cac doanh nghiep ma ca vdi cac cu dan dd thi.
Cuoc hdi thao nay do Cong ty APAVE to chifc la nham muc dich trao doi va chia se cac quan di^m quan ly trong dau tu va xay dung cac cdng trinh ngam dd thi riit tif kinh nghiep ciia cac nudc.
Cac dai bieu du hpi thao da nghe tham luan ciia cac cue, vu Bo Xay dong. Bo TN-MT eae So Xay dung Ha NPi, TP Ho Chi Minh ve: Phat tnen cong tnnh ngam trong do thi, phap luat dat dai doi vdi cong trinh ngam; quy hoach, quan ly dau tu xay dung cdng trinh ngam dd thi tai Ha Noi, TP. HCM, va cong tac kiem tra, chimg nhan su phu hop chat luong xay dung du an Metro.
Cac tham luan ciia cac chuyen gia nudc ngoai nhu: Nhat
Ban, Han Quoc, Oai Loan, APAVE Phap, APAVE Trung Quoc da chia se cac kinh nghiem trong viec quan ly va phat tnen cong trinh ngam tai cac nudc nay
Hoi thao da cung cap nhieu thong tin bo' ich ve dau tu xay dung he thong cong trinh ngam d dd thi doi vdi nudc ta. Oac biet cac tham luan deu de xuat nhumg van de can quan tam nhu:
Sdm CO quy hoach tdng the he thong khong gian ngam tai cac do thi Idn: cac quy chuan, tieu chuan thiet ke, xay dung cac cong trinh do thi can sdm duoc ban hanh; quyen sd hCru cong tnnh ngam va quyen sir dung dudi mat dat; co che chinh sach d^ thu hill von dau tuxay dung cdng tnnh ngam..,a
NGl/dl
X A Y D I / N Gs d THANG 7 • 2009
