_^^ KHOA HOC VA CANG N O H E MO NGHIEN CUU XAC DjNH SO LUffNG PHirONG PHRP BO TRI CflC L MJN HOP LV TRCN GirONG THI CONG CONG T R I N H NGAM GS.TS VO TRQNG HUNG Truxmg Dai hgc Mo-Dia chat —^ au x^c ^nh s6 lu-grig 16 min, ngii-b-i thiet k l ^ d n tiln h§nh bo tri cac 16 tren gifcng thi ^ ^ c6ng cong trinh ng§m Vi^c xSc 5jnh s6 lu'p'ng vd phifo'ng phdp b6 tri c§c lo tren gu'O'ng phai dam bao cdc ySu c3u va hi^u qua cho cdng tdc khoan n6 S6 lu'p'ng va phu-ong phap b6 tri cdc l6 trSn gu-ang la nhu'ng tiiong so khoannS quan trpng thiet ke cong ngh# thi c6ng c6ng trinh ngam Tuy nhifin, cho din cdc th6ng so ky thuat ndy Vdn chu-a du'p'c xdy dp'ng mOt cdch chuan xdc Nhi^u chl dan cdc tai li$u thiet k l ky thu^t v l vin d l ndy van mang tinh djnh tinh Nhilu ludn dilm rit ma h i Vi vay, vi^c nghien cO-u xdy dyng phu'ong phdp xdc ^nh s6 lu'p'ng vd bd tri cdc lo mm hpp ly tren gu'O'ng thi cong cong trinh ngam c6 y nghTa thyc t l rit lo-n [1], [2], [3] Ly thuylt chung v l cac phu'ang phap xac djnh s6 lu'p'ng va bd tri cac Id tren gu'O'ng Cdng tdc xdc djnh so lu'p'ng vd b l tri cdc l§ trfen gu'O'ng thi cdng con^ trinh ngdm phai thyc hi^n theo mOt so nguyen tdc ca ban nhu' sau [2]; • Dam bao dgt du'p'c hi#u qua cao nhdt cho cdng tdc khoan nd nh&ng dilu ki0n dja ca hpc mdi tru'6'ng ddt dd eg thi, cho nhu-ng hinh dang, kich thu'd'c mat cdt ngang cdng trinh ngim eg thi vdi nhOng thdng so ky thudt-cdng ngh0 nhit djnh cua hp chieu khoan nd min; • Dam bao h0 so SIJ dgng lo "T\" dgt gid tri Id-n nhit (gia tdng gdn bdng 1,0); • Dam bao h# so thCFS tilt di^n V" d?t gid trj nho nhit (giam xuong gan bdng 1,0); • Dam bao mCpc dp dap vd' deu ddn cua dat dd sau khoan n l Dam bao mire dp vdng xa nho nhit cua dat dd sau no (dd sau bj phd huy t$p trung chu yeu khu vyc gin gu'ang thi cdng cdng trinh ngam); • Dam bao kha nang anh hu'dng it nhlt-td-i khoi dd bao quanh cdng trinh ngam, cdc cdng trinh ngim Idn can, mat dit, cdc cdng trinh xdy dyng tren mat ddt, ; • Dam bao cdc Id phai dupc bo tri deu ddn, hpp ly tren toan bO gu'ang thi cdng cdng trinh ngim; • Mdi l5 phai dam nhif m kha ndng phd huy vCing dit dd du'p'c "ky vpng" thudc vdo ndng lye cua minh; • Dam bao gu'ang thi cdng sau thyc hi?n cdng tdc khoan nd cd dp sai l^ch It nhit so vd'i hinh dang, kich thu-d-c mat cdt ngang thi cdng cdng trinh ngam theo thiet ke; • Khoang cdch giOa edc vdng l6 "b" vd khoang cdch giCra hai lo "c" eCjng mOt vdng (hang) Id khdng du'p'c Idn han gid tn du'dng can toi thilu (du'dng can nho nhit) "W": b hai cho gu'ang thi cdng cdng trinh ngim Chung Joai cau tao eua nhdm lo dpt phd se tiln hanh xdc djnh theo nh&ng chi dan d^c bi$t, ddc chung; • Nhdm - Nhdm cdc l6 phd (nhdm B) Cde l6 cd edng dung pha huy phan Idn khii dat dd eho gu'ang thi cdng cdng trinh ngim Cdc l6 phd du'pc thiet k l toy theo nhOng d$c dilm clu tgoCONG NGHIEP MO StfO-2014 ^2I_ KHOA HOC VA GONG NGHE MP clu trOc, tinh chit cua dat dd trgn gu'ang vd nhOng dilu ld$n thi cdng khdc; *:• Nhdm - Nhdm cdc lo bi§n (cdc l3 tao bidn) (nhdm C) Cdc l5 cd cdng dgng tao ndn bidn cdng trinh ngam theo dung ttiilt k l Nhdm cdc l6 ndy se nim cdch du-dng bidn hdng va ndc mdt khoang tli Ihilu vd Idp lai hinh dang du'dng bidn hdng vd ndc cua cdng trinh ngam eg thi; *:* Nhdm - Nhdm cdc l5 nen (cdc l l tao nin) (nhdm D) Cdc l6 ndy cd cdng dgng tao nen nin cdng trinh ngim theo dOng thilt k l Nhdm cdc l5 ndy se ndm cdch du'dng bidn nin mOt khoang tli thilu vd Idp lai hinh dang difdng bien nin cua cdng trinh ngim eg thi; *:* Nhdm - Nhdm cdc l5 ddc bi$t (nhdm E) Cdc l5 thudc nhdm ndy sO dgng d l khic phge sy phdn b l khdng diu cua cac lo d cdc nhdm l5 b l tri canh d l trdnh hipn hfpng dd qud cd xuit hi$n khoang cdch giOa cdc l6 qud Idn Cdc i l ndy thu'dng xudt hi$n nh&ng cdng trinh ngim cd hinh dang mdt elt ngang phCrc ta^ bidn cd gde canh, gdy khue, bien khdng tran Si tin tai cua ehung du'p'c thilt ke cho nh&ng cdn trinh ngim cd cac ddc dilm clu tao hinh hpc d | bi0t Trong nhilu tnrdng hp'p chiing ed t h i du-p ghdp vdo nhdm cdc l5 phd Ngodi ra, tai ddy c t h i tin tai edc l6 d l hinh thdnh rdnh tho^ nu'dc vd phgc vg cho cdc chCrc ndng khde Trong dd, nhdm edc l5 d|t phd, nhdm cdc I bien, nhdm cdc lo nin vdn hdnh nhOn dilu kipn d$e bift hodc ed cdng dgng ddc bipt nhdr cdc Id ddt phd vdn hdnh dilu ki$n chT c mOt mdt phdng ty do, cho ndn kit clu, kich thu-d vd sa d l b l \r\ cua cde l6 nhdm dOt ph rit da dang; nhdm cdc l6 bien, cdc l5 ne dOng de tao nen mdt bidn, mdt nen cdng trtnh ngir theo dung thilt k l Vi vay, edc nhdm lo ndy phi du'pc thiet k l vdi nhttng yeu cau ddc bipt d l cd th sO dgng nhO-ng dilu kidn khdch quan nhdm thd mdn cdc ydu clu k$ thudt-edng ngh^ eg thi H f Sa nguyen tic bStricAcid tr§n gwang thi c6ng cho m^t s6 cdng ttinh ngim c6 hlnh d^ng m^t cit ngang kh^c nhau: a - M$t cit ngang hinh chO nh$t; b - M$t dt ngang hinh thang; c - M$t cSt ngang hinh vdm-tu^ng thing; d - M$t cit ngang hinh vdm tird'ng thing-vdm ngifQc; e - l\/l$t cit ngang hinh vom-tu^ng cong; g - M$t cit ngang hinh vom-tu^ng cong-vdm ngiK^c; h^- Chiiu cao thi cdng ICen nhit cOa cdng trinh ngim, m; ht, - Chiiu cao thi cdng cda tu^ng-v6m cdng'^hinh ngim m; h^ - Chiiu cao thi cdng cua vdm ngwqtc cdng trinh ngim, m; B^^ - Chiiu i^ng thi cdng l&n nhit (khiu ng phan "dipn tich dan vj" ed hinh dang, kich thu-dc eg thi rit khdc bao quanh chung (H.2, H-3) Nghien ciru d l xudt nhu-ng djnh hu'dng ca ban xac djnh s6 lu'p'ng va phu'ang phap bd tri hp'p ly^ cdc Id tren gu'ang D l d l xuit nhOng djnh hu'dng tinh s i lu'png vd xay dyng sa bo tri cdc lo trdn guang, diu tien cin xdc ^nh tdng sd lu'p'ng l5 "N" theo mdt phu'ong phap ly thuylt-thyc nghipm ndo dd (vi dg theo phuang phdp cua Pokrovski N.M [2]) Khi mdt cdt ngang cdng trinh ngam cd dang doi xdng hinh vdm-tudng thdng du-ng (H.2) vi0c xdc dinh nhOng dinh hudng ea ban cho phuang phdp bo tri cdc lo trdn guang se dupc tiln hdnh nhu sau Gid tri "didn tich dan vj" trung binh "Sdvtb" cho mli Id tren guang cd thi xdc djnh theo cdng thdc: -m (1) Tai ddy: Stc - Di$n tfch cua guang thi edng cdng trinh ngim, m^; N - Tdng s i lup'ng l6 tinh todn cho todn bp guang thi cdng cdng trinh ngdm Ngodi ra, gid tri "dipn tich dan vi" trung binh "Sdvtb" dy kiln tinh cho mSi lo tren guang cd t h i xdc djnh bdng mli quan hp sau ddy: Sdvtb=[(b).(c)], m^ (2) Tgi day: b - Khoang each gida hai hang (vdng) l6 eanh nhau, m; e - Khoang each giua hai l6 canh ciJng mdt vdng l5 min, m Cde gid tri "b", "c" phai dong thdi thoa mdn cdc dieu ki$n sau ddy: b Bydc 10 - Xdc dinh cdc khoang cdch "Cp.", ting s l lupng cdc l6 phd "Np" cdc vdng phd (khdng k l cdc l l diu vd ciioi cua vdng lo phd thudc v l vdng l l nin) theo cdng thyc (21); ; Bydc 11 - Xdc dinh khoang cdch "cpp", so lupng l l nhdm l l ddt phd "Ndp" thee cdng thijc (22) hodc theo mdt nhdm l l ddt phS dd chpn eg the ndo dd; •:• Budc 12 - Xdc dinh s l lypng l l vdng l l nin "N„" sO dgng phyang phdp khoan n l thdng thydng theo cing thuc (23); • Bydc 13 - Xdc djnh khoang cdch "Cm"; s6lypng l l vdng l l nen "Nm" sO dgng phuang phdp khoan n l tao nin ddc bi$t theo cdng thuc (24); •> Bydc 14 - Xdc dinh ting s l cdc l l "NM" thudc nhdm cdc l l ddc bi|t (cdc t l thudc nhdm 5) tren gyang thi cdng cdng trinh ngim; • Budc 15 - Xdc dinh tong s l cdc l l trdn gyang thi cdng "NK" phyang phdp khoan no thdng thudng theo cdng thuc (25); •:• Budc 16 - Lya chpn vd thilt ke kit cau nhdm dpt phd ddc bi0t Xdc dinh s l lupng cdc l l "Nap," CLia nhdm ddt phd dac bidt Xdc dinh phdn didn tich cua nhdm cdc l l ddt phd ddc bipt "lln sdn" vdo phin dipn tich cua cdc l l phd Xdc dinh s l lypng cdc l l phd bi suy giam "Npo" bi nhdm cdc l l ddt phd ddc bi|t "chllm dgng" mit; •:• Budc 17 - Xdc dinh ting s l cdc l l trdn gyang thi cdng "NK" phuang phdp khoan nl thdng thydng cd sy dgng kdt c l u nhdm ddt phd ddc bipt theo cdng thiic (26); ^ •:• Budc 18 - Xdc dinh s l lypng cdc lo tao nen "No," sy dgng phyang phdp khoan n l tao nen ddc bidt; •:• Budc 19 - Xdc dinh ting so cdc l l trdn guong thi cdng "N^" sy dgng phyang phdp khoan n l tao bidn, tao nin dac bipt vd kit clu nhdm l l ddt phd dac bipt theo cdng thuc (27) Khi sy dgng cdc loai mdt cdt ngang cdng trinh ngim khdc hinh vdm-tydng thing flCrng (hlnh H.I a, b, d, e, g), ngydi thilt kl^phli tiln hdnh (Xem tiSp trang 25) ... t h i (5an xen (it phCrc tap theo dilu ki$n thi cong cdng trinh ngim cu thi Tren H.1 gi6''i thi$ u mOt s6 so d l nguySn tic b l tri cdc |5 trSn guang thi c6ng m$t s i c6ng trtnh ngim cd hinh dang... tird''ng thing-vdm ngifQc; e - l\/l$t cit ngang hinh vom-tu^ng cong; g - M$t cit ngang hinh vom-tu^ng cong-vdm ngiK^c; h^- Chiiu cao thi cdng ICen nhit cOa cdng trinh ngim, m; ht, - Chiiu cao thi. .. cdng''^hinh ngim m; h^ - Chiiu cao thi cdng cua vdm ngwqtc cdng trinh ngim, m; B^^ - Chiiu i^ng thi cdng l&n nhit (khiu