KHOA HOC VA CONG NGHE MO ]/ NGHICN CU'U XSV DU'NG PHlfONG PHRP LY THUYET TONG QUAT XAC D|NH CHIEU SAU LO MIN KHI THI CONG CONG TRINH NGAM GS.TS VO TRONG HUNG Trwcrng Dai hgc Mo-Dja chat Tong quan Hien nay, van de xac dinh chieu sau lo thi cdng cdng trinh nglm cd t h i tilp can theo ba nhdm phuang phap sau day: • Nhdm thif nhit - Chpn trudc gia tri chilu sau lo theo yeu elu t i c dp tiin guang; • Nhdm thif hai Xac djnh chilu sau 16 theo kinh nghiem thi cdng thyc t l ; • Nhdm thu' ba Xac djnh chilu sau 16 theo cac cdng thirc thyc nghiem N l u t i c dp dao 16 mpt thang "Vih" (m/thang) dupc djnh trudc thi chieu sau 16 "I" cd the xac djnh theo cdng thirc sau [1]: Vth.T,.^ — 1= ,m T.(25^30).Ti Trong dd: Tck - Thdi gian ciia mpt chu ky thi cong cdng trinh nglm, gid; T Thdi gian lam viec ciia cac dpi thg thi cdng mpt dem, gia/ngay; (25^-30) S l lam viec mdt thang, ngay/thang; ri - He so sir dung lo Mac du viec lya chpn chilu sau " I " theo kinh nghiem cho k i t qua nhanh chdng, nhung phuang phap lam cho cdng tac quy hoach, to chirc thi cdng chu ky cdng tac trd nen phipc tap Trong nhieu trudng hgp, ngudi thiet k l rat khd va thudng khdng the tao nen cac chu ky thi c6ng phii hgp vdi nhd'ng diiu kien may, thilt bj thi cdng, nhd-ng dac tfnh cau tao cu the ciia cdng trinh nglm va cac dieu kien a nhd'ng khu vyc xay dyng cu the Thyc t i c h o thiy, hai nhdm phugng phap chpn chieu sau lo theo yeu cau t i c dp t i i n gugng va theo kinh nghiem chi sir dung thyc t l bat bupc, hoac nhd'ng diiu kien thi cong phu'c tap, tiin dp gugng phai thay doi theo timg chu ky c6ng tac cu the tren nhd'ng doan cong trinh ngam cd cau tao dac trung (vi du thi c6ng cac doan duang Id giao CONG NGHIEP MO S - 2017 cat nhau, nga ba, nga tu, ) Hal nhom phuang phap phai dugc nghien cifu hoan thien, vi tai day vSn t i n tai r i t nhilu van d l chu-a du-pc giai dap t h i u dao ve kha nang SLP dung hpp ly cua chung tren thyc te: • Sau xac djnh xong gia trj "1", bang each nao nguai thilt k l c6 t h i dam bao dLpgc viec gia trj "I" da xac djnh cd the hoan tren thyc te? • Gia tri chilu sau lo " I " da dugc chpn lu-a thieu rat nhilu chipng CLP luan giai; • Lam each nao ngudi thiet ke co the giai bai toan nguge "phai tim cac d i i u kien to chirc, ky thuat, cdng nghe, phii hgp d l c6 the dat dugc gia trj " I " c i n thilt tren thyc te" Day la bai toan rit phu-c tap vi chilu sau 16 phu thupc vao rit nhieu y l u to, thay doi lien tuc thupc vao cae d i i u kien khac tren thyc te Cac phuang phap xac djnh chieu sau lo theo cac cong thirc thyc nghiem kh6ng mang tinh tong quat Moi c6ng thu-c thyc nghiem chf cd the giai quyit cho tu-ng tru-ang hgp thi cdng cu the, nhd-ng d i i u kien xay dyng nhit djnh, cho nen chung co r i t nhieu han c h i va kh6ng t h i SLP dung 6- nhd-ng d i i u kien khac [1], [2], [3] Nhd-ng van de tren chf co t h i giai q u y i t tren co sd k i t qua nghien ciru phuang phap xac djnh ehieu sau 16 trudng hgp tong quat tif cac yeu t l : sa to chirc chu ky c6ng tac da dugc chpn trudc; cac tinh chit, nang lye, chiing logi ciia cac trang-thiet bj thi c6ng san cd; cac dieu kien mo, dja chit, dja ca hpc cu the ciia khu vyc xay dyng c6ng trjnh n g l m ; kha nang bao dam ky thuat (cung c l p nang lu-gng, dien, nen, th6ng gid, van tai, ) d mirc dp can thilt cho qua trinh thi c6ng, Ngoai ra, tai day cd t h i phai xet d i n nhd-ng sy co, tai nan, nhu-ng y l u to ngiu nhien co the xay qua trinh thi cong c6ng KHOA HOC VA CONG NGHE MO trinh n g l m Cac y l u t l c i u co the thay doi hoac khong thay doi nhd-ng d i i u kien thi c6ng nhat djnh xac djnh c6ng thirc tong quat xac djnh chilu sau 16 Cac yeu to anh hiro'ng den chieu sau lo Chilu sau lo la mpt th6ng s l khoa hpc, ky thuat, cong nghe, thi c6ng, to chipc, san xuat, d i i u phii, van hanh, rat phipc tap qua trinh xay dyng c6ng trinh ngam V l nguyen tic, chieu sau lo se phu thupc vao mpt s l nhom yeu to ca ban nhu sau: • Nhom - Cac y l u to tudng minh "x" cd gia trj khong thay doi, co the danh gia djnh lugng qua trinh thi cdng cong trinh ngam: > Cac yeu cau thilt k l thi c6ng c6ng trinh nglm; > Cac y l u t l tudng minh c6 gia tri khong thay doi, c6 the danh gia djnh lugng mdi trudng thi c6ng c6ng trinh n g l m ; > Cac th6ng s l quy hoach, cau tao cdng trinh ngam; > Oieu kien xay dyng ciia khu vyc thi c6ng c6ng trinh n g l m ; > Chiing loai, dac tinh ky thuat, c6ng nghe, van hanh, ciia cac may, thilt bj cd t h i sir dung d l thi c6ng cong trinh ngam; • Nhom - Cac y l u t l tudng minh "yi" cd gia trj thay doi, cd the danh gia djnh lugng qua trinh thi cong c6ng trinh ngam: > Cac y l u t l tugng minh cd gia trj thay doi, cd the danh gia djnh lugng mdi trudng thi cong c6ng trinh n g l m ; > Phuang thirc to chiPC cac cdng tac qua trinh thi c6ng toan b6 c6ng trinh ngam; > Phuang thirc t l chirc cac c6ng viec mpt chu ky thi c6ng cdng trinh nglm; > Tnnh ty noi tiep, song song thyc hien cac cdng viec e l u chu ky thi cong eong trinh ngam; > Kha nang tiin hanh dgc lap hoan toan, dgc lap tu-ng phin, kh6ng t h i dpc lap ciia cac c6ng viec chu ky thi c6ng c6ng trinh nglm; > So lupng, chiing loai may, thiet bj cd the sudung d l thi c6ng cong trinh nglm; > s l lugng nhan lye, cdng nhan cd t h i sir dung de thi cdng cdng trinh nglm; > Mifc anh hudng lan ciia dgi ngu cdng nhan, can bp ky thuat qua trinh thi c5ng cdng trinh ngam; > Mirc dp anh hudng l i n ciia cac loai may, thilt bj, qua trinh thi cong c6ng trinh nglm; • Nhdm - Cac y l u t l tudng minh "z," cd anh hu-dng d i n chilu sau lo qua trinh thi cdng c6ng trinh nglm nhung rat khd hoac kh6ng the danh gia djnh lugng: > Cac y l u to tuang minh rat kho hoac khong t h i danh gia djnh lu-png moi trydng thi c6ng cong trinh n g l m ; > Nang lye kinh te, tai chinh, may, thiet bj, cua dan vj thi c6ng; > Trinli dp to chipc thi c6ng cua nguai lanh dao, nguai quan ly; > Trinh dp thi cong ciia dpi ngu c6ng nhan, can bp ky thuat; > Cac chfnh sach kinh t l , xa hpi, co anh hu-dng d i n moi tru-ang thi cong c6ng trinh n g l m ; > Sy anh hudng ciia m6i tru-arig d i n kha nang hoat dpng cua c6ng nhan, may, thilt bj, qua trinh thi c6ng c6ng trinh nglm; ; > K i t qua nghien cifu ly thuyet, thyc nghiem, xac djnh chieu sau lo min; > Kha nang bao dam ky thuat (cung c l p nang lupng, dien, khf nen, th6ng gid, van tai, ) 6- mirc dp c i n thiet cho qua trinh thi c6ng; • Nhdm - Cac y l u t l kh6ng tudng minh "wi" nhung cd anh hudng d i n chilu sau lo qua trinh thi c6ng cong trinh n g l m : > Cac yeu t l kh6ng tudng minh m6i trudng thi c6ng cong trinh n g l m ; > Cac dac tfnh elu tao, irng xu- kh6ng tuang minh cua cac phin cau m6i truang thi cong; > Cac tai nan; cac sy co; > Cac true trac to chirc, ky thuat, c6ng nghe, thi c6ng, ; > Cac sy ngung nghf vo cd; > Cac y l u to ngiu nhien; > MLPC dp, quy luat anh hudng lan ciia cac y l u t l gay nen sy anh hudng tai chilu sau 16 min; Trong dd, hai nhdm yeu to dau tien co mipc dp anh hudng Idn n h i t d i n dai lugng c h i l u sau lo Nhdm y l u t l thu- ba cd miPc anh huang r i t cao Tuy nhien, kha nang danh gia chiing tren thyc t l r i t khd nen c i n t i l p tuc nghien cu-u de CO t h i sip dung chiing qua trinh hoan thien cac phuang phap xac djnh c h i l u sau lo Nhdm y l u to thir tu mac dii mang tinh thai diem, mang tfnh n g i u nhien, bat chat, nhu-ng lai cd mirc anh hudng manh nhat Mgt hoac mgt so y l u to, sy kien ciia nhom thir t u xay se lam ngung tre toan bg qua trinh thi c6ng c6ng trinh ngam mgt khoang thdi gian n h i t djnh, pha vg nhjp do, trinh t y thi cdng cong trinh n g l m da chpn, loai bd hoan toan chu ky thi cdng thong thudng cho c6ng trinh ngam da t h i l t k l Ngoai ra, tat ca cac y l u to anh hudng c6n gay nen nhu-ng tac dgng, anh huang r i t phirc tap lan nhau, chju sy tac dpng va tac dpng len m6i truang thi c6ng c6ng trinh n g l m (H.i) CONG NGHIEP MO S - KHOA HOC VA CONG NGHE MO Cac yeu cau thiet ke thi cong cong trinh ngam I I Moi tryo-ng thi cong cong trinh n g l m To hgp cac y l u to anh huo-ng d i n chilu sau lo T T Nhom cac y l u to tyo-ng minh CO gia tri khong thay doi co t h i danh gia dtnh lypng "xi" Nhom cac y l u to tucyng minh co gia trj thay doi CO the danh gia dinh lypng "yi" T Nhom c^c yeu t l tyo-ng minh kho ho$c khong t h i danh gia djnh lu-gng "z" Nhom cac yeuti khflng tyo-ng minh I L Phu-ang phap xac djnh chieu sau l5 H Scr dd mo ta mdi quan he giira cac nhom yiu td anh huang dSn phuang phap xac djnh chliu sau lo Nhu vay, gia trj chilu sau lo thi c6ng c6ng trinh nglm se la mpt ham so phirc tap phu thupc vao to hpp cua r i t nhieu y l u t l khac dual dang tong quat nhu sau: l=f(Xi,yi,Zi,w/i) _ (2) Tai day: Xi - Cac yeu t l tudng minh cd gia trj kh6ng thay doi, cd the danh gia djnh lugng den sy anh hudng d i n chieu sau 16 "I"; i=1-^qi; qi - Gia trj ldn nhit cd the cua so lugng cac y l u t l tudng minh, khdng thay doi gia trj, cd anh hudng d i n chilu sau 16 " I " ; y - Cac y l u t l tudng minh c6 gia trj thay doi, cd the danh gia djnh lu-gng mipc anh hudng d i n chieu sau lo "I", i=1-^q2; q2- Gia trj Idn n h i t cd the ciia so lugng cac y l u to tudng minh CO gia trj thay doi, cd t h i danh gia djnh lugng mu-c dp anh hudng den chilu sau lo "I"; Zi - Cac y l u td tudng minh nhung khd hoac khdng the danh gia mu-c dp anh hudng djnh lugng d i n chieu sau 16 "I", i=1-^q3; qa- Gia trj ldn nhit co the cua so lugng cac y l u to tudng minh nhung kho hoac khong the danh gia mirc dp anh hud-ng djnh lupng d i n chilu sau 16 'T'; W| - Cac y l u to khong tudng minh cd anh hudng d i n chilu sau lo "I", i=Uq4; q4 - Gia trj Idn nhit cd the ciia s l lugng cac y l u to chua bilt cd anh hudng den f(l) = chilu sau 16 "I"; f - Ham s6 lien k i t cac y l u to Xi, yi, Z|, W| Tip cac dieu kien thi c6ng cong trinh n g l m , sau lya chpn p h i n cac cong viec, dac tinh to chipc thyc hien cac cong viec, tong thdi gian 'Tck" cua mpt chu ky thi c6ng cong trinh n g l m se cau tip tong cac khoang thdi gian "T.kj" cua cac cong viec thip "i" thyc hien n i i t i l p mot chu ky thi c6ng [1]: Tck=Z(^-ki) (3) Tai day: T^k - Thai gian cua mot chu ky thi cdng; n - Toan bp s l lugng c6ng viec phai hoan khoang thdi gian cua mpt chu ky thi c6ng "Tck"; Ti - Thai gian c i n thiet d l hoan cong viec thip "i", gid; ki - He s l t h i hien mipc dp dpc lap thyc hien phin cdng viec thip "i"; 0