KHOA HOC CONG NGHE
So 04/2020
Mpt so ton tai trong cong tac lap da toan kiem djnh cong trinh xay dung
• PGS. TS. OANG TH) XUAN MAI - TrUdng Dgi hge Giao thong van tdi
TOM TAT: Bai bao phan tich mdt so ton tgi bat cap trong khi lap du toan kiem dinh cong trinh xay dyng nhu ve djnh muc, don gia ap dung va ngi dung each tinh du toan
T L ; KHOA: Du toan, kiem djnh cong trinh ABSTRACT: This paper analyzes some inadequacies in the work of estimating Construction inspection such as norms, applied unit prices and the content of estimation method.
KEYWORDS: Estimate, testing, norm
L D A T V A N D i
Chat lugng edng trinh xay dung la tap hop eae d i e tinh thuat eua eong trinh xay dUng dUOc xie djnh thdng qua kiem tra, do die, thi nghiem, kiem djnh thda man cac yeu cau ve an t o i n , ben vQng, ky thuat, my thuat cua eong trinh va phu hgp vdl thiet ke, eae quy ehuan, tieu chuan ky thuat dugc i p dyng, hgp ddng xay dUng va quy dinh p h i p l u i t cd Hen quan. Tuy nhien, eong t i e lap d u t o i n kiem djnh trong nhQng nam qua edn bgc 16 mpt so bat cap dan tdi viee khong chuan xie trong viec xae dinh ehi phi kiem dinh gay khd k h i n trong viee q u i n ly cht phi d i u tU xay dQng edng trinh, thi'm dinh, phe duyet v i thUc hten dQ an dau tQ xay dQng,
2.GlAlQUY^TVANDg
TheoThong tUsd 26/2016fTT- BXD ngay 26/10/2016 cuaBdXaydUng vequy dmh ehi tiet mpt sd ngi dung ve quan ly chat lugng va b i o tri cdng trinh xay dUng nhU sau: Kiem dinh chat iugng eong trinh xay dUng (kiem dinh) l i hoat ddng kiem tra, xic dinh eha't lupng eua san phi'm xiy dUng, bg p h i n eong trinh hoac cong trinh xay dung so vdi yeu eau cua thiet ke v i eac quy chuan, tieu chuan ky t h u i t thong qua viee thi nghiem ket hgp vdl viee xem xet, d i n h gia hien trang bang true quan.
LTnh vUe kiem dmh bao gdm:
- Kiem dinh ehat iQOng, xae djnh nguyen nhan hu hdng, thdi ban sQ dung eita bg phan eong trinh, eong trinh xay dung va kiem djnh de xae dinh nguyen nhin sU ed edng trinh xiy dung;
- Kiem djnh chat lugng vat lieu x i y dQng, eau kien xay dung, sin pham xay dUng,
Kiem dinh chuan doan ky t h u i t edng trinh xay dung thudng duoe tien h i n h trong cae trudng hgp sau:
- Kiem dtnh chat lugng cong trinh dang sQdung;
- Kiem djnh chat luong trong dieu tra sued edng trinh;
- Kiem djnh chat lugng va cap chUng nhin chat lugng eong trinh xiy dung phu hap,
Kiem djnh l i mgt cong tac mang tinh d i e thu eao.
Oe euong kiem djnh ehi ed hieu luc khi dugc cO quan cd thi'm quyen hoie chu cong trinh ra quyet djnh phe duyet ve noi dung va dU toan. Tuy nhien, hien nay chua cd mgt quy djnh cu the n i o ve ndi dung cua du toan kiem dinh nen trong thuc te van dUa tren eic ndi dung cua dQ toan xay dQng eong trinh.
Trude n i m 2007 (thdi ky ehUa co dinh mQe, don gii phue vu cong t i e kiem dtnh), du toan kiem djnh dugc lap dua tren eic cosd chu yeu sau:
- Hd so de euong kiem djnh: Oe cUOng kiem dmh neu ehi tiet eic ndi dung cae ngi dung can thue hien trong thue te. Oe cUOng la dieu kien tien quyet eho mot ho so d u t o i n ; nd cd the bao gdm t o i n bd thong tin ve du an, eae b i n ve ket ci'u, khoi lugng chi tiet de lap du t o i n kiem djnh eong trinh.
- Kinh nghiem cua ngUdi l i p dU t o i n : Cong tac kiem djnh l i cong tac dae thu nen ngUdi lap dU toan kiem djnh phai l i nhQng ngQdi da tham gia vao mot qua trinh thuc hien ngoat hien trudng tren mgt ddl tUOng kiem tra eu the. Can cQ v i o npi dung eong vtee ma ngUdi l i p d u t o i n tuean ddi dinh mUc de cd the b i o ve dugc trudc CO quan ed tham quyen,
Nhu viy, quan diem chu quan cua ngudi lap dU t o i n ed i n h hUdng rat Idn den g i i tr; dutoan kiem dinh.
Tuy theo nang lUe cua don vj kiem t o i n ngudi l i p dU toan se udc lugng sd edng, sd ea may phu hgp vdi tQng cdng viee trong qua trinh kiem djnh, Oieu dd vQa lam g i i m tinh khach quan, tinh thdng nha't eua du toan vUa g i y khd khan eho cong t i c phe duyet du t o i n eua don vj quan ly.
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2.1. Ve ^ n h muTc dung trong lap dutoan kiem dinh
*Tdnam 2007-2013 (khi CO bo'dan gid kiem dinh cua TP Ho Chi Minh):
Ngay 15/5/2007, UBND TP. Hd Chi Minh ban hanh tam thdt dOn g i i cho cong t i c thQtai eau dudng bd khu viJcTP. Ho Chi Minh. Oay chi la quyet dinh tam thdt i p dyng eho mot 6\a phuang cu the nen nhieu tinh, thanh khdng coi do la mpt v i n b i n phap ly ehung chinh thUe, nhung eo quan q u i n ly van eho phep cae don vt lap du t o i n kiem dinh eong trinh giao thong van dung va b i o ve di; toan kiem dinh (vi ehua ed mgt v i n b i n ban h i n h dmh mQe cu the cho edng t i e kiem dinh).
Bg don g i i ra ddt da d i n h dau mdt bUde p h i t tnen cho cong t i e l i p du t o i n kiem dinh. Co rat nhieu eong t i c kiem djnh da dUOc bo dan gia de cap den. Nhu viy, gta tri d u t o i n da phan nao g l i m bdt phy thudc v i o chu quan cua ngudi l i p dutoin.Tuy nhien, trong bd don g i i nay khdng cd dinh mUc, dan den viec lap dieu chinh don gia kho khan. Vt eae dieu ehinh ehii yeu lien quan den dieu ehinh chi phi n h i n cong ma khdng dteu chinh duge ehi phi sQ dyng may v i ehi phi nguyen vat lieu. Viec dieu chinh chi pht nhan edng eung ehi la tuong ddi khi ma eich tinh chi phi n h i n cong thay dot theo tUng giai doan khong gidng nhau.
*Tdndm2013 den nay:
Ngay 29/7/2013, Bo GTVT 6a ban hanh Quyet dinh sd 2204/00- BGTVT ve viee edng bd dinh mUe du t o i n mpt sd cong t i c kiem dinh xay dUng cho dQ an tin dung nganh GTVT de eai tao mang ludi dUdng quoe gia lan thU2.0inh mQc nay da bUde dau thdng nhat cae don vj tUvan kiem djnh tren t o i n qude khi thuc hien eic hgp ddng kiem djnh edng trinh dang khai t h i c theo ngudn vdn du i n tin dung nganh GTVT de eii tao mang iQdi dudng qude gia lan thU hai ndi ehung va sQ dung cho cic hop ddng kiem dinh khac sau nay.
Co the ndi d i y la bo djnh mUe day du nhat cho cdng tae kiem dinh. Nhd ed bd djnh mQe nay m i cong tic lap du t o i n kiem dinh trd nen de d i n g hon, quy cu hon v i chinh xac ban. Tuy nhien, bd djnh mQc nay van cdn thieu mot sd cong t i e trong qua trinh kiem dinh nhQ: cdng t i e thi sat thu thap sd lieu, lap de cuong thQ t i i , cong tae ve so dd quy dinh vj tri v i dieu ddng t i t do...
Hien ngay trong cong t i e t i p dU toan kiem djnh thudng hay sQ dyng eae djnh mQe cua tieu ehuan thi nghiem (Quyet djnh sd 1169 n g i y 14/11/2017 cua Bg Xay diJng ve Ojnh mQe thi nghiem v i t lieu, ket cau va cong trinh xay dung), O i y la mgt tat lieu rat tot eho thUe hien eic cong t i c n g o i i hien trUdng nhUng trong tap dinh mQc van cd mgtsd diem chQa phu hop vdt thUcte, ey the nhu sau:
-Tiet dinh mQe DB 700 Thi nghiem kiemtra cUdng do be tong cua cau kien va be tong cot thep tai hien trudng. V i t lieu giay r i p (nhim) sd 0 la chQa dung vdi thuc te vi cd the ein nhieu loai giay rap khie nhau tuy thuoc be mat be tdng mdi hay cu, cd b i n g phang nhieu hay it, cd bj phong hda hay khong. Trong cie dieu kien cho phep thl thudng dung may cha rapeam tay de thuc
KHOA HOC CONG NGHE
So 04/2020 hien tdt edng t i c nay. Ve m i y mde thiet bj thi trong cic thi nghiem hien trudng ludn can them m i y i n h de ghi nhan, xae thuc eong viee, nhUng dieu nay ehua dugc the hien trong djnh mUc. Trong p h i n mo ta yeu eau cong vtee eung chua the hten rd bien p h i p d i n h g i i la thi nghiem ngau nhien hay thi nghiem theo iQdl toa do vdl cie dinh mUe khic nhau v i yeu eau iQa chgn bien p h i p cu the vdi tQng ioai eau kien thi nghiem.
- Tiet djnh mQe DB 2400 cong tae do Qng suit dam.
Trong bang dinh mQc ehi ghi cd sensor dien tQ l i ehUa day du. Vtee do Qng suit eo the dung nhieu thiet b\ khae nhau nhu tenzometer co hpe, dien trd, dien dung, ddng ho do bien dang, quang hge... Sensor dien tQ rat mdng manh, de hu hat ma trong dinh mQc khdng xet den khau hao thi khd thue hien doge (mQe hQ hdng cd the den 30%). Oinh mQe keo d i n eung khong rd rang, trong dinh mQc ghi theo hop thl rat khd xie djnh ma nen dmh mQc theo gam, kg hoic theo milylit, lit.. Trong phan md t i cd ghi noi dung "cho xe ra"la dung eho d i m eau vi chat t i t bang xe, NhQng vdl nhieu loai eau khac nhU cau bg hanh, eau ming, cau bang t i i khi khdng chi't t i i bang xe 6 to hay xe IQa dQge tht can p h i i cd dmh mQc xep tai rieng. Trong dinh mQe niy cung chQa tinh den eae he sd c h o d d k h d c u a e a c d i e m d o n h Q v j tri tren cao, rung lic, gid giat, thuc hien trong dem toi thieu i n h sing, trong khdng gian chat hep...
- Tiet dmh mQc DB 2500 edng t i e do Qng suit b i n mat eau, cung tuong tU nhU do Ung suit dam. Bo dp vdng tTnh dam ddi vdt nhQng nhjp eau qua song la edng t i c cd dd khd eao ban so vdi cac nhip tren bd. Trong djnh mUc can ed he sd hay dinh mUe phii hgp vdi viec do cac dam eau tren mat nUde, dong ehiy xtet, cd gto manh, dieu kien dat may khd khan hoac trong dieu kien cau tren cie tuyen quan trong khong the dUng khai thie bude phai thuc hien edng tac do dae vao ban dem.
-Tiet djnh mUc DB 2700 xac djnh do vdng do hoat t i l dat tTnh cua dam, Trong djnh mUc ehi ed khi sd diem do > 5, nhung trong thue te ed cau ehi cd hai dtem do nhueau dam dudng sit, eic c i u d to chi cd 02 hay 3 dam chu thi chua CO dinh mUe eho cac trudng hop nay.Trong djnh mUc ehi do do vong bang indieateur. NhQng khi ed ddng ehiy manh, lUu tdc Idn hoac cac dam ed cao do Idn, ed gid thdt manh thi khong the do qua d i y do tha xudng neo dudi d i y song duge vi sai sd qua mQc. Vdt cie eau Idn, c i u d i y vang, cau treo..., do vong Idn vugt q u i k h i n i n g cua eae indicater cung khdng thUe hien dugc.
Viec do do vdng cd the thUe hien bang cae thiet bi khie nhu may do ehuyen vi dien tQ, may eao d i e dien tQ, may phat laser vdi man hinh dat tat diem do... NhQ vay, djnh mQe ean eo them do do vong b i n g eae thiet b\ nay,
- Tiet djnh mQc DB 2800 eong t i c do dao dong ket ci'u nhip cau; tiet djnh mUc DB29000 cong t i c do dao dgng va chuyen vj md tru eau. Trong thUe te, khi do dao ddng thudng cin ed may tinh xich tay kem theo. Can dua m i y tinh vao dinh mQc hao phi miy vi m i y do dao dgng chQa ghi lai dUoc eie ket q u i nhU tren may tinh, Trong cdng t i c do dao ddng dung t i l trgng d to, xe IQa nhung
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KHOA HOC CONG NGHE
So 04/2020
tdt hon l i dung thiet bl dao dong ngau nhien.Trong dmh mQc nen bo sung thiet bi tao dao dgng ngau nhien.Trong mo ta q u i trinh cdng viee nen sQa lat trong djnh mQc l i : ehi dQng lai khi khdng edn i n h hQdng den ket qua do (trong dinh mQc ghi la dQng khi sd lieu do on dtnh).
Tren d i y la mpt sd dmh mQe thudng sQ dung khi lap du toan kiem dinh cau. Ndt ehung, dinh mUc thi nghiem eon mdtsd tdn tai nhQsau:
- Cie dinh mQc hau nhQ cht xet den dteu kien cua phong thi nghiem, ma chUa xet den dieu kien ngoai hien trudng.
Oinh mQc keo e i p dQ Ung luc; dtnh mQc pha huy bu-16ng chUa xet den yeu td dUdng kinh, vj tri do cao khd tiep can, trong khong gian hep, kin, eo d n h i i m khdng khi, tieng dn... Vdl eie djnh mQc xac dtnh chat IQgng kim loai bang quang phd, sieu i m do ehieu day kim loat thi trong eie dinh mQe chua xet den dp khd, dp nguy hiem, 6 nhi^m eung nhU chQa xet den eie thiet bi d i e ehung, thiet bj phu tro nhu can ci'u, da g i i o ngoai edng trUdng de do mau.
- SQdyng ki hieu khong thong dung hoac thieu.
Odi vdi kich thQde mau tru nen ehi ro kieh thude dudng kinh v i dung ki hieu dudng kinh la <I> hay D khong nen dung ki hieu f khdng thdng dyng. Can them dan vj l i mm,
- Mpt sd tQ ngQ ehua thdng nhat:
-H) Kiem tra eudng do be tdng luc thi dung sung ban bt, luc thi dung sung b i t nay. Nen dimg thdng nhi't mpt loai;
-1-) Vdi mat eat ngang thi nen diing tU tiet dien thay eho tU thiet dien;
+) Xac dinh cUdng do gach xay la gach trong eic khdt x i y hay cua vien gaeh khi de rdi;
+) Oo dien trd tai hien trudng thi can ghi rd l i m i y do dien van n i n g chQ khong nen ghi ia "may do van nang"
- Mgt sd thi nghiem tat hten trudng can bd sung them may anh, may tinh xich tay vi can xae dmh dieu kien thuc te v i m i y tinh duge ket ndi ghi lat sd lieu, hinh i n h eu the.
- Mdt sd djnh mUe chUa xet tdi hao phi m i y mdc van chuyen thiet bj den hten trudng nhu xic djnh eudng do betdng bang phuong p h i p khoan li'y mau.
- Mdt so dinh mQe nhan cdng thap nhQ cong t i e xac djnh do tham ion Cl" vao trong be tong, xie djnh he sd khuech t i n cua ion C!" trong be tdng.
Ve dinh mQc khio sat cung thudng duge sQ dung nhQ la tieu chuan dinh mQe de lap d u t o i n cho cong t i c kiem djnh (Quyet dmh sd 1354 ngay 28/12/2016 dinh mdc du t o i n khao sat). Trong ngi dung 10 ehuong eua djnh mQe nay khdng de cap den cac eong t i e khio sat thuy v i n , thuy liJc nhu mQc nQdc, lUu tdc dong chay, dja h'mh, dia mao ddng song; eung nhQ khdng de cap den eac mQc hao phive trang bi bao hg an t o i n lao dgng eho con ngQdi v i may mde thiet bi khi tien hanh cdng viee k h i o sit. Mgt sd diem chQa rd ring trong cie dmh mQe khio sat eo the neu ra lam v i d u nhQsau:
+ Tiet dinh mUe CA.1000 dao dat da bang tay thi can quy djnh cu the han the n i o la dao dat da b i n g tay
vi eac m i y mde, thiet bj c i m tay nhU tdi, cau, khoan phi luon duge sQ dyng v i mQc do trang bi duge tinh den nhQ the nio? Trong dtnh mUc nay cung khong de cip den dieu kien d i o trong ttnh trang ngap nUdc. M i t khic, vtee d i o da bang tay, eap da khac nhau cd do cQng khic nhau rat nhieu, nen viee ehi p h i n chia lam hai mQe: cap I- III v i IV-V la chQa thda d i n g .
+ Cic tiet dinh mQe ve dao ed chong nhU: CA 12000;
CA12100, CA 12200; CA12300 trong b i n g dinh mUc luon ed loai v i t lieu la go chong. Thuc te hien nay d i thay the v i t lieu ehdng bang eae eiu kien thep hoae vat lieu khae, vl vay nen bd sung them cac loai v i t lieu khac.
-HTiet dinh mUe CA 21100 O i o gieng dQng nen cd edng thQc ehung de tinh ddi eae ehieu sau, cap di't da, luu luong nude ngam de tinh t o i n t h u i n tien va de ding hon. V i , eung nen ed phy luc ehi ro dieu kien kho khan la gl? Od khong chi la d vung rQng nui, khi hau khae nghiet, dt lat kho khin, m i eon p h i i tinh tdl dieu kien khong the van ehuyen ngudi va thiet bj bang ca gtdi,
-nCic ttet djnh mUe CE 12500Thi nghiem nen tTnh thQ tai cgc be tong bang phuang phap coc neo v i CA 12600: Thi nghiem nen tTnh thQ t i l cgc be tong bang phuong p h i p chat tai deu la thi nghiem nen tTnh, ehi khic nhau phuong p h i p chit t i i nen thiet bl do do lun ed the dung gidng nhau. Vi vay, trong ea hat thi nghiem deu cd the dung ddng hd chuyen vl hoie thCiy binh dien tQ cd dp chinh xie dat yeu eau tuy theo dteu kien i p dung eho thuan lgi, cho ket q u i tin ciy.
-HTiet dtnh mQc CE 12700Thi nghiem kiem tra ehat iQgng cgc be tdng bang phQong phap bien dang nho (PIT) ve phan m i y thi eong cd ten la thiet bi do bien dang la chQa chinh xac, nen got la may thi nghiem bien dang nhd PIT dung eho be tong.
+ Tiet dinh mQc CE 12900 Thi nghiem kiem tra chat luong cgc be tong b i n g phUOng p h i p sieu i m thi trong djnh mQc chQa de cap den chieu dat cgc, vi cd nhieu cong viee, nhieu so lieu can xQ ly han khi ehieu dai coc Idn,
+Tiet djnh mQe CH 11300 Oo ve mat eat dgc d dUdi nudc va CH 11400 do ve m i t eat ngang d dUdl nUde chi ed y nghTa ddi vdi nhQng ddng chay luu tdc thap, song khdng sau vi khongthedat mia tQday song; nen bo sung nhQng bien p h i p khie, nhQng thiet bl phu hop thQc hien khi dieu kien kho khan ban nhutrong dinh mQc.
2.2. Ve don gia va noi dung each t i n h chi phi trong dUtoan ki^m djnh
Tren d i y l i mdt sd tdn tai trong viec ap dung dmh mUe khi lap d u t o a n kiem dinh edng trinh giao thong thudng gap. Ve p h i n dOn g i i thl hau het cac v i t lieu sQ dung deu khong eo trong thong b i o g i i cita eic dia phQOng dan den viee ap gia vat lieu ri't khd khan nhQ:
gii'y rip, md bo, bang dinh, son do, son t r i n g , dTa tQ...
Ve don g i i nhan eong thi khi lap d u t o i n kiem dinh eung cdn CO nhQng diem ehua phu hop nhU ehi phi nhin cong true tiep thl tinh theo luong tdi thieu vung nhQng luong eua chuyen gia, kysUthi dugc xac dtnh theo mQc luang casd (vidy do dao dgng ketcau nhjp eo sQdyng cong n h i n bae 4/7 va ky sU bie 4/8). Ve cht phi may thl
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KHOA HOC CONG NGHE
So 04/2020 edng thi trong edng t i e kiem djnh sd lugng may dung
khong nhieu nhUng lai dung nhieu loai m i y d i e ehung khong cd trong danh mijc theo quy djnh, vi v i y viec tinh t o i n gia ca may khong thdng nhat ve each chgn nguyen gii eua may, chgn cich tinh khi'u hao (eung vdt vi du do dao ddng ket cau nhip dung m i y do dao dgng dien tQ NEC-VM 511-2/2 va dau do Indicator,..),
Ve ngi dung eua dutoan kiem dinh eung khdng ed hudng dan ey the, eie dan vj kiem djnh thudng l i p du t o i n theo thdng le tU trUde v i tuy thudc v i o ben giao thau. Vl du nhu, van dung theo du toan xay diJng edng trinh, trong dd Gkd dugc van dung l i p theo Gxd bao gdm chi phi true tiep, cht phi ehung, thu nhap ehiu thue tinh trUde, thue g i i tri gia t i n g . Nhung neu van dung lap theo d i ; toan cdng tac khao s i t thi du t o i n kiem dinh se bao gdm ehi phi true tiep, chi phi ehung, thu n h i p ehiu thue tinh trUdc, ehi phi khic, thue gta tri gta t i n g v i ehi phi duphdng.
3. KET L U A N
Tdm lai, viec td chdc kiem dinh chit lugng eong trinh xay dQng la mdt cdng vtee quan trgng. Cic chi phi cho eong t i c kiem dinh ean p h i i dUgc ti'nh dung, tinh du nham dam b i o thue hien eae ehuong trinh, eie ngi dung trong de cuang, trong hgp ddng kiem dinh dUOc thyc hien dung tien do, dung chat lugng d i de ra. Mgt trong eicdleu kien dam bao suthanh cdng cua edng tac kiem dtnh la phit khae phuc eac ton tat trong eong t i e l i p dU t o i n kiem dinh eong trinh x i y dUng.
Tai lieu tham khao
[1]. Chu Viet Binh, Nguyen Nggc Long, Nguyen Manh, Nguyen Van Nham (2009), Kiem dinh cau, NXB.
Xay dung. Ha Ngi,
[2]. Quyetdinh so 1354 ngdy28/12/2016 cua BgXdy dung ve viee eong bo dinh mdc du todn xdy ddng cong trinh phan khao sdt xdy dung.
[3]. Quye'r dinh so 1169 ngdy 14/11/2017 eua Bo Xdy ddng ve viee cong bo dinh mdc dU todn xdy dung cong trinh phan thi nghiem vdt Hiu, cdu kien, ket cdu vd cong trinh xdy ddng.
[4]. Thong tdso 01 ngdy 6/02/2017 ve viee hddng ddn xdc djnh va qudn ly ehi phi khao sdt.
[5]. Nguyen Viet Trung (2008), Gido trinh Kiem tra, kiem dinh, gia co, sda ehda cau cong, TrUdng Oai hge GTVT, H i Ndi.
Ngay nhan bai: 12/01/2020 Ngay chap nhan dang: 05/02/2020 NgUdi phihn bien: GS. TS. TiJT Sy Siia
PGS.TS.TranThi Lan HUOng
