Kinh nghi\u1ec7m khi b\u00f3c kh\u1ed1i l\u01b0\u1ee3ng d\u1ef1 to\u00e1n
1. KINH NGHI\u1ec6M KHI B\u00d3C KH\u1ed0I L\u01af\u1ee2NG D\u1ef0 TO\u00c1N ( Ph\u1ea7n 1 )<\/p>\n
***1\/ B\u00f3c ph\u1ea7n b\u00ea t\u00f4ng kh\u00f4ng tr\u1eeb th\u00e9p hay d\u00e2y bu\u1ed9c chi\u1ebfm ch\u1ed7 \u0110i\u1ec1u n\u00e0y nhi\u1ec1u ng\u01b0\u1eddi bi\u1ebft nh\u01b0ng c\u0169ng c\u00f3 nh\u1eefng ng\u01b0\u1eddi kh\u00f4ng bi\u1ebft quy \u01b0\u1edbc \u1edf \u0111\u00e2u. Xin th\u01b0a \u0111\u01b0\u1ee3c quy \u0111\u1ecbnh t\u1ea1i m\u1ee5c 3.3 ph\u1ea7n II trong Quy\u1ebft \u0111\u1ecbnh 788\/2010\/BXD v\u1ec1 vi\u1ec7c c\u00f4ng b\u1ed1 h\u01b0\u1edbng d\u1eabn vi\u1ec7c \u0111o b\u00f3c kh\u1ed1i l\u01b0\u1ee3ng c\u00f4ng tr\u00ecnh. Tuy nhi\u00ean khi l\u1eadp h\u1ed3 s\u01a1 thanh quy\u1ebft to\u00e1n m\u1ecdi ng\u01b0\u1eddi c\u0169ng c\u1ea7n ch\u00fa \u00fd: V\u00ec l\u00e0 kh\u00f4ng tr\u1eeb th\u00e9p chi\u1ebfm ch\u1ed7 n\u00ean nhi\u1ec1u khi kh\u1ed1i l\u01b0\u1ee3ng v\u1eefa b\u00ea t\u00f4ng trong th\u1ef1c t\u1ebf d\u00f9ng \u00edt h\u01a1n r\u1ea5t nhi\u1ec1u, v\u00ed d\u1ee5: 1000m3 b\u00ea t\u00f4ng \u0111\u00e1ng ra ph\u1ea3i d\u00f9ng h\u1ebft 1015m3 kh\u1ed1i v\u1eefa (\u0111\u1ed5 b\u1eb1ng b\u01a1m), tuy nhi\u00ean th\u1ef1c t\u1ebf \u0111i mua v\u1eefa ch\u1ec9 mua c\u00f3 990m3 ch\u1eb3ng h\u1ea1n. \u0110i\u1ec1u n\u00e0y ko \u1ed5n n\u1ebfu b\u1ea1n xu\u1ea5t tr\u00ecnh h\u00f3a \u0111\u01a1n ch\u1ee9ng t\u1eeb khi quy\u1ebft to\u00e1n, nguy\u00ean t\u1eafc h\u00f3a \u0111\u01a1n v\u1eabn ph\u1ea3i ghi \u0111\u1ee7 1015m3.<\/p>\n
*** 2\/ B\u00f3c b\u00ea t\u00f4ng ph\u1ea3i tr\u1eeb \u0111i c\u00e1c khe co gi\u00e3n, l\u1ed7 r\u1ed7ng tr\u00ean b\u1ec1 m\u1eb7t k\u1ebft c\u1ea5u b\u00ea t\u00f4ng c\u00f3 th\u1ec3 t\u00edch > 0,1m3. \u0110i\u1ec1u n\u00e0y c\u0169ng quy \u0111\u1ecbnh t\u1ea1i M\u1ee5c 3.3 ph\u1ea7n II \u2013 Q\u0110788 \u2013 BXD M\u1ecdi ng\u01b0\u1eddi \u0111\u1ecdc c\u00e2u n\u00e0y c\u00f3 th\u1ec3 s\u1ebd suy ngh\u0129 ngay: v\u1edbi kh\u1ed1i l\u01b0\u1ee3ng c\u00e1c khe, l\u1ed7 tr\u00ean b\u1ec1 m\u1eb7t c\u00f3 th\u1ec3 t\u00edch <= 0,1m3 th\u00ec kh\u00f4ng ph\u1ea3i tr\u1eeb. Tuy nhi\u00ean kh\u00f4ng h\u1eb3n nh\u01b0 th\u1ebf, \u0111i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a b\u1ea1n kh\u00f4ng tr\u1eeb th\u00ec c\u0169ng kh\u00f4ng sai, nh\u01b0ng n\u1ebfu Ch\u1ee7 \u0111\u1ea7u t\u01b0 y\u00eau c\u1ea7u ph\u1ea3i tr\u1eeb \u0111i th\u00ec v\u1eabn tr\u1eeb b\u00ecnh th\u01b0\u1eddng. V\u00ec ch\u1ec9 n\u00f3i ph\u1ea3i tr\u1eeb khi th\u1ec3 t\u00edch >0,1m3 ch\u1ee9 kh\u00f4ng n\u00f3i l\u00e0 <0,1m3 th\u00ec \u201ckh\u00f4ng tr\u1eeb\u201d nh\u01b0 tr\u01b0\u1eddng h\u1ee3p th\u00e9p nh\u01b0 tr\u00ean .<\/p>\n
***3\/ B\u00f3c c\u1ed1p pha ph\u1ea3i tr\u1eeb \u0111i \u0111i c\u00e1c ph\u1ea3i tr\u1eeb c\u00e1c khe co gi\u00e3n, c\u00e1c l\u1ed7 r\u1ed7ng tr\u00ean b\u1ec1 m\u1eb7t k\u1ebft c\u1ea5u b\u00ea t\u00f4ng c\u00f3 di\u1ec7n t\u00edch > 1m2 \u0110i\u1ec1u n\u00e0y quy \u0111\u1ecbnh t\u1ea1i M\u1ee5c 3.4 ph\u1ea7n II \u2013 Q\u0110788 \u2013 BXD Nhi\u1ec1u b\u1ea1n c\u00f3 th\u1ec3 ngh\u0129 d\u01b0\u1edbi 1m2 kh\u00f4ng ph\u1ea3i tr\u1eeb, tuy nhi\u00ean c\u0169ng nh\u01b0 tr\u01b0\u1eddng h\u1ee3p b\u00f3c b\u00ea t\u00f4ng th\u00ec vi\u1ec7c d\u01b0\u1edbi 1m2 Ch\u1ee7 \u0111\u1ea7u t\u01b0 v\u1eabn c\u00f3 th\u1ec3 y\u00eau c\u1ea7u nh\u00e0 th\u1ea7u tr\u1eeb l\u00e0 b\u00ecnh th\u01b0\u1eddng. Nh\u01b0ng xin l\u01b0u \u00fd: kh\u00f4ng tr\u1eeb th\u00ec kh\u00f4ng t\u00ednh c\u1ed1p pha th\u00e0nh, nh\u01b0ng \u0111\u00e3 tr\u1eeb th\u00ec l\u1ea1i ph\u1ea3i t\u00ednh c\u1ed1p pha th\u00e0nh. T\u01b0\u01a1ng t\u1ef1 \u1edf m\u1ee5c 3.10- Ph\u1ea7n II c\u0169ng quy \u0111\u1ecbnh v\u1edbi c\u00f4ng t\u00e1c ho\u00e0n thi\u1ec7n, n\u1ebfu c\u00e1c khe co gi\u00e3n hay l\u1ed7 r\u1ed7ng c\u00f3 di\u1ec7n t\u00edch b\u1ec1 m\u1eb7t >0,5m2 th\u00ec ph\u1ea3i tr\u1eeb. N\u1ebfu <=0,5m2 th\u00ec b\u1ea1n c\u00f3 th\u1ec3 tr\u1eeb ho\u1eb7c kh\u00f4ng tr\u1eeb v\u00e0o b\u1ea3n t\u00ednh to\u00e1n.<\/p>\n
***4\/ B\u00f3c c\u1ed1p pha c\u1ed9t, c\u1ecdc vu\u00f4ng BTCT \u0111\u00fac s\u1eb5n t\u00ednh 2 m\u1eb7t hay 3 m\u1eb7t? C\u00f3 m\u1ed9t s\u1ed1 \u0111\u01a1n v\u1ecb ki\u1ec3m to\u00e1n khi ki\u1ec3m tra vi\u1ec7c b\u00f3c t\u00e1ch c\u00f4ng t\u00e1c v\u00e1n khu\u00f4n c\u1ed9t hay c\u1ecdc btct \u0111\u00fac s\u1eb5n th\u01b0\u1eddng t\u00ednh ch\u1ec9 c\u00f3 hai m\u1eb7t, h\u1ecd l\u00fd lu\u1eadn, do \u0111\u1ecbnh ngh\u0129a, di\u1ec7n t\u00edch v\u00e1n khu\u00f4n l\u00e0 ph\u1ea7n di\u1ec7n t\u00edch v\u00e1n c\u00f3 ti\u1ebfp x\u00fac v\u1edbi b\u00ea t\u00f4ng (quy \u0111\u1ecbnh t\u1ea1i Q\u0110 788- BXD). Tuy nhi\u00ean vi\u1ec7c n\u00e0y l\u00e0 kh\u00f4ng \u0111\u00fang, n\u1ebfu nh\u01b0 ch\u1ec9 t\u00ednh hai m\u1eb7t th\u00ec nh\u00e0 th\u1ea7u c\u1ea7n \u0111\u01b0\u1ee3c t\u00ednh chi ph\u00ed \u0111\u1ec3 l\u00e0m b\u00e3i \u0111\u00fac, t\u1ee9c mu\u1ed1n \u0111\u00fac \u0111\u01b0\u1ee3c c\u1ecdc th\u00ec c\u1ea7n ph\u1ea3i c\u00f3 b\u00e3i \u0111\u00fac v\u00e0 \u0111\u00f3 l\u00e0 m\u1ed9t ph\u1ea7n chi ph\u00ed \u0111\u1ec3 c\u00f3 \u0111\u01b0\u1ee3c c\u1ecdc b\u00ea t\u00f4ng. Nh\u01b0 v\u1eady t\u00ednh v\u00e1n khu\u00f4n c\u1ed9t, c\u1ecdc vu\u00f4n BTCT 3 m\u1eb7t l\u00e0 ph\u00f9 h\u1ee3p.<\/p>\n
***5\/ B\u00f3c t\u00e1ch kh\u00f4ng chia chi\u1ec1u cao c\u00f4ng tr\u00ecnh Tr\u01b0\u1edbc \u0111\u00e2y, khi b\u00f3c t\u00e1ch ng\u01b0\u1eddi ta \u0111\u00e3 chia chi\u1ec1u cao c\u00f4ng tr\u00ecnh th\u00e0nh c\u00e1c m\u1ee9c <4m, t\u1eeb 4 – 16m, t\u1eeb 16- 50m v\u00e0 >50m \u0111\u1ec3 b\u00f3c c\u00e1c c\u00f4ng vi\u1ec7c. Th\u1ef1c ra vi\u1ec7c n\u00e0y kh\u00f4ng \u0111\u00fang. Chi\u1ec1u cao quy \u0111\u1ecbnh trong \u0110\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c Vi\u1ec7n kinh t\u1ebf B\u1ed9 x\u00e2y d\u1ef1ng x\u00e1c nh\u1eadn l\u00e0 chi\u1ec1u cao c\u00f4ng tr\u00ecnh, v\u00e0 khi b\u00f3c t\u00e1ch, n\u1ebfu chi\u1ec1u cao c\u00f4ng tr\u00ecnh \u1edf m\u1ee9c n\u00e0o th\u00ec b\u00f3c c\u00e1c m\u00e3 hi\u1ec7u \u1ee9ng v\u1edbi chi\u1ec1u cao \u0111\u00f3. V\u00ed d\u1ee5: T\u00f2a nh\u00e0 cao 20 t\u1ea7ng c\u00f3 chi\u1ec1u cao 70m th\u00ec to\u00e0n b\u1ed9 c\u00e1c m\u00e3 hi\u1ec7u c\u00f4ng vi\u1ec7c s\u1ebd > 50m. M\u1edbi \u0111\u00e2y trong \u0110\u1ecbnh m\u1ee9c 1091, B\u1ed9 x\u00e2y d\u1ef1ng c\u0169ng \u0111\u00e3 m\u1ed9t l\u1ea7n n\u1eefa nh\u1eafc l\u1ea1i \u201cchi\u1ec1u cao quy \u0111\u1ecbnh trong \u0110M l\u00e0 chi\u1ec1u cao c\u00f4ng tr\u00ecnh\u201d.<\/p>\n
***6\/ Ph\u1ea7n giao nhau t\u00ednh v\u00e0o c\u1ea5u ki\u1ec7n n\u00e0o? V\u00ed d\u1ee5: D\u1ea7m v\u00e0 c\u1ed9t, b\u00ea t\u00f4ng hay v\u00e1n khu\u00f4n \u0111\u01b0\u1ee3c t\u00ednh v\u00e0o ph\u1ea7n n\u00e0o? Th\u1ef1c ra kh\u00f4ng c\u00f3 m\u1ed9t quy \u0111\u1ecbnh n\u00e0o v\u1ec1 vi\u1ec7c ph\u1ea7n giao nhau gi\u1eefa c\u00e1c k\u1ebft c\u1ea5u \u0111\u01b0\u1ee3c t\u00ednh v\u00e0o k\u1ebft c\u1ea5u n\u00e0o. V\u00ec v\u1eady vi\u1ec7c b\u00f3c v\u00e0o \u0111\u00e2u ph\u1ee5 thu\u1ed9c v\u00e0o quy\u1ebft \u0111\u1ecbnh c\u1ee7a ng\u01b0\u1eddi th\u1ef1c hi\u1ec7n \u0111o b\u00f3c. Tuy nhi\u00ean th\u01b0\u1eddng t\u00e2m l\u00fd c\u1ee7a ng\u01b0\u1eddi l\u1eadp d\u1ef1 to\u00e1n th\u00ec t\u00ednh v\u00e0o \u0111\u00e2u thu\u1eadn l\u1ee3i v\u00e0 nhanh nh\u1ea5t s\u1ebd t\u00ednh v\u00e0o \u0111\u00f3, t\u00e2m l\u00fd c\u1ee7a ng\u01b0\u1eddi thi c\u00f4ng th\u00ec t\u00ednh v\u00e0o \u0111\u00e2u c\u00f3 l\u1ee3i h\u01a1n d\u00f9 tr\u00ean th\u1ef1c t\u1ebf kh\u1ed1i l\u01b0\u1ee3ng n\u00e0y kh\u00f4ng qu\u00e1 nhi\u1ec1u. M\u00ecnh xin \u0111\u01b0a ra m\u1ed9t v\u00ed d\u1ee5 so s\u00e1nh \u0111\u1ec3 m\u1ecdi ng\u01b0\u1eddi tham kh\u1ea3o: – B\u00ea t\u00f4ng c\u1ed9t s\u1ebd cao h\u01a1n b\u00ea t\u00f4ng d\u1ea7m (\u0111\u1ebfn h\u00e0ng ch\u1ee5c ngh\u00ecn 1m3) – Tuy nhi\u00ean v\u00e1n khu\u00f4n d\u1ea7m l\u1ea1i cao h\u01a1n v\u00e1n khu\u00f4n c\u1ed9t (m\u1ea5y ngh\u00ecn 1m2)<\/p>\n
KINH NGHI\u1ec6M KHI B\u00d3C KH\u1ed0I L\u01af\u1ee2NG D\u1ef0 TO\u00c1N ( Ph\u1ea7n 2 ) *** PH\u1ea6N \u00c9P C\u1eccC B\u00ca T\u00d4NG *** ——————————————————– Ph\u00e2n bi\u1ec7t \u00e9p c\u1ecdc tr\u01b0\u1edbc v\u00e0 \u00e9p c\u1ecdc sau:<\/p>\n
1\/ Ph\u1ea1m vi s\u1eed d\u1ee5ng bi\u1ec7n ph\u00e1p: – \u00c9p Tr\u01b0\u1edbc: th\u01b0\u1eddng l\u00e0 c\u00e1c c\u00f4ng tr\u00ecnh thi c\u00f4ng m\u1edbi, c\u1ecdc \u00e9p c\u00f3 \u0111\u01b0\u1eddng k\u00ednh ph\u1ed5 bi\u1ebfn t\u1eeb 20×20 \u0111\u1ebfn 40×40 (th\u01b0\u1eddng l\u00e0 25×25 v\u00e0 30×30) – \u00c9p sau: th\u01b0\u1eddng l\u00e0 khi c\u1ea3i t\u1ea1o, s\u1eeda ch\u1eefa m\u00f3ng c\u00f4ng tr\u00ecnh, c\u1ecdc \u00e9p ch\u1ec9 t\u1ed1i \u0111a 25×25 (th\u01b0\u1eddng l\u00e0 15×15, 20×20, 22×22)<\/p>\n
2\/ C\u00f4ng ngh\u1ec7 m\u00e1y \u00e9p: – \u00c9p Tr\u01b0\u1edbc: d\u00f9ng c\u00e1c \u0111\u1ed1i tr\u1ecdng ch\u1ea5t t\u1ea3i, m\u00e1y \u00e9p c\u00f3 chi\u1ec1u cao 4- 5m – \u00c9p sau: d\u00f9ng m\u00e1y \u00e9p k\u00edch th\u1ee7y l\u1ef1c + gi\u00e1 \u0111\u1ee1<\/p>\n
3\/ \u0110\u1eb7c \u0111i\u1ec3m t\u1eebng bi\u1ec7n ph\u00e1p: – \u00c9p Tr\u01b0\u1edbc: \u00e9p nhanh, chi\u1ec1u s\u00e2u c\u1ecdc l\u00e0 l\u1edbn, c\u1ecdc c\u00f3 k\u00edch th\u01b0\u1edbc l\u1edbn, t\u1ea3i tr\u1ecdng \u00e9p do \u0111\u00f3 l\u1edbn. M\u00e1y thi c\u00f4ng \u00e9p c\u1ecdc sau kh\u00f4ng th\u1ec3 \u00e9p v\u1edbi c\u00f4ng tr\u00ecnh \u0111\u00e3 thi c\u00f4ng nay c\u1ea7n s\u1eeda ch\u1eefa, v\u00ec k\u00edch th\u01b0\u1edbc \u0111\u1ed3 s\u1ed9 c\u1ee7a m\u00e1y k\u00e8m theo m\u1ed9t l\u01b0\u1ee3ng t\u1ea3i b\u00ea t\u00f4ng \u0111\u00fac s\u1eb5n ph\u1ee5c v\u1ee5 \u00e9p. Nh\u00e2n c\u00f4ng \u00e9p c\u1ecdc tr\u01b0\u1edbc ch\u1ee7 y\u1ebfu l\u00e0 ph\u1ee5c v\u1ee5 vi\u1ec7c c\u1ea9u c\u1ecdc v\u00e0o v\u1ecb tr\u00ed, \u0111i\u1ec1u ch\u1ec9nh c\u1ecdc v\u00e0o v\u1ecb tr\u00ed \u00e9p. – \u00c9p sau: \u00e9p ch\u1eadm, ph\u1ea3i c\u00f3 c\u1ecdc d\u1eabn, k\u00edch th\u01b0\u1edbc c\u1ecdc ng\u1eafn v\u00e0 nh\u1ecf, t\u1ea3i tr\u1ecdng \u00e9p kh\u00f4ng l\u1edbn. M\u00e1y ch\u1ec9 l\u00e0 k\u00edch v\u00e0 gi\u00e0n gi\u00e1 \u0111\u1ee1 g\u1ecdn nh\u1eb9 n\u00ean ph\u00f9 h\u1ee3p v\u1edbi c\u00f4ng tr\u00ecnh mang t\u00ednh ch\u1ea5t s\u1eeda ch\u1eefa, gia c\u1ed1. Nh\u00e2n c\u00f4ng \u00e9p c\u1ecdc tr\u01b0\u1edbc ch\u1ee7 y\u1ebfu l\u00e0 ph\u1ee5c v\u1ee5 vi\u1ec7c v\u1eadn chuy\u1ec3n c\u1ecdc th\u1ee7 c\u00f4ng, \u0111\u01b0a c\u1ecdc v\u00e0o v\u1ecb tr\u00ed, \u0111i\u1ec1u ch\u1ec9nh c\u1ecdc v\u00e0o v\u1ecb tr\u00ed \u00e9p (c\u00f4ng nhi\u1ec1u h\u01a1n \u00e9p c\u1ecdc tr\u01b0\u1edbc) – V\u1ec1 quy tr\u00ecnh v\u00e0 nghi\u1ec7m thu c\u00f4ng t\u00e1c \u00e9p c\u1ecdc b\u1ea1n c\u00f3 th\u1ec3 tham kh\u1ea3o b\u1ed9 TCVN – TCXD
3. KINH NGHI\u1ec6M KHI B\u00d3C KH\u1ed0I L\u01af\u1ee2NG D\u1ef0 TO\u00c1N ( Ph\u1ea7n 3 ) ***D\u1ef0 TO\u00c1N CHO C\u00d4NG T\u00c1C \u0110\u00d3NG \u00c9P C\u1eccC*** \u0110\u1ec3 \u00e9p hay \u0111\u00f3ng 100m c\u1ecdc, ng\u01b0\u1eddi ta ph\u1ea3i d\u00f9ng 101m. V\u1edbi \u0111\u00f3ng c\u1ecdc th\u00ec t\u1ed1n th\u00eam 1,5 % VL kh\u00e1c v\u00e0 \u00e9p c\u1ecdc th\u00ec con s\u1ed1 n\u00e0y l\u00e0 1%, con s\u1ed1 VL Kh\u00e1c t\u00f9y theo t\u1eebng \u0110M b\u1ea1n nh\u00e9. Tuy nhi\u00ean khi l\u1eadp d\u1ef1 to\u00e1n \u00e9p c\u1ecdc, ng\u01b0\u1eddi ta th\u01b0\u1eddng b\u1ecf VL c\u1ecdc ra ngo\u00e0i d\u1ef1 to\u00e1n, c\u00f3 ngh\u0129a l\u00e0 \u0111\u1ec3 t\u00e1ch ri\u00eang th\u00e0nh d\u1ef1 to\u00e1n \u0111\u00fac c\u1ecdc ho\u1eb7c m\u00e3 hi\u1ec7u TT (Mua c\u1ecdc), m\u00e0 hao h\u1ee5t theo \u0111m \u1edf tr\u00ean, l\u00e0 1% VL c\u1ecdc t\u1ee9c ph\u1ea3i nh\u00e2n 1,01, c\u00f2n VL kh\u00e1c c\u0169ng ph\u1ea3i \u0111\u01b0\u1ee3c t\u00ednh ch\u1ee9? V\u1eady l\u00e0 Mua c\u1ecdc hay \u0110\u00fac c\u1ecdc \u0111\u1ec1u ph\u1ea3i t\u00ednh 1% VL kh\u00e1c! Trong qu\u00e1 tr\u00ecnh \u00e9p c\u1ecdc, khi \u00e9p c\u1ecdc t\u1edbi \u0111o\u1ea1n cu\u1ed1i c\u00f9ng, ta ph\u1ea3i c\u00f3 bi\u1ec7n ph\u00e1p \u0111\u01b0a \u0111\u1ea7u c\u1ecdc xu\u1ed1ng m\u1ed9t c\u1ed1t \u00e2m n\u00e0o \u0111\u00f3 so v\u1edbi c\u1ed1t t\u1ef1 nhi\u00ean. C\u00f3 th\u1ec3 d\u00f9ng 2 ph\u01b0\u01a1ng ph\u00e1p 1\/ Ph\u01b0\u01a1ng ph\u00e1p 1: D\u00f9ng c\u1ecdc ph\u1ee5 \u2022 D\u00f9ng m\u1ed9t c\u1ecdc BTCT ph\u1ee5 c\u00f3 chi\u1ec1 d\u00e0i l\u1edbn h\u01a1n chi\u1ec1u cao t\u1eeb \u0111\u1ec9nh \u1ecdc trong \u0111\u00e0i \u0111\u1ebfn m\u1eb7t \u0111\u1ea5t t\u1ef1 nhi\u00ean m\u1ed9t \u0111o\u1ea1n (1 \u2013 1,5m) \u0111\u1ec3 \u00e9p h\u1ea1 \u0111\u1ea7u c\u1ecdc xu\u1ed1ng cao tr\u00ecnh c\u1ed1t \u00e2m c\u1ea7n thi\u1ebft. \u2022 Thao t\u00e1c: Khi \u00e9p t\u1edbi \u0111o\u1ea1n cu\u1ed1i c\u00f9ng, ta h\u00e0n n\u1ed1i ti\u1ebfp m\u1ed9t \u0111o\u1ea1n c\u1ecdc ph\u1ee5 d\u00e0i \u2265 2,5m l\u00ean \u0111\u1ea7u c\u1ecdc, \u0111\u00e1nh d\u1ea5u l\u00ean th\u00e2n c\u1ecdc ph\u1ee5 chi\u1ec1u s\u00e2u c\u1ea7n \u00e9p xu\u1ed1ng \u0111\u1ec3 khi \u00e9p c\u00e1c \u0111\u1ea7u c\u1ecdc s\u1ebd t\u01b0\u01a1ng \u0111\u1ed1i \u0111\u1ec1u nhau, kh\u00f4ng x\u1ea3y ra t\u00ecnh tr\u1ea1ng nh\u1ea5p nh\u00f4 kh\u00f4ng b\u1eb1ng nhau, gi\u00fap thi c\u00f4ng \u0111\u1eadp \u0111\u1ea7u c\u1ecdc v\u00e0 li\u00ean k\u1ebft v\u1edbi \u0111\u00e0i thu\u1eadn l\u1ee3i h\u01a1n. \u0110\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u1ed9 s\u00e2u n\u00e0y c\u1ea7n d\u00f9ng m\u00e1y kinh v\u0129 \u0111\u1eb7t l\u00ean m\u1eb7t tr\u00ean c\u1ee7a d\u1ea7m th\u00e9p ch\u1eef I \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh cao tr\u00ecnh th\u1ef1c t\u1ebf c\u1ee7a d\u1ea7m th\u00e9p v\u1edbi c\u1ed1t \u00b10,00, t\u00ednh to\u00e1n \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c chi\u1ec1u s\u00e2u c\u1ea7n \u00e9p v\u00e0 \u0111\u00e1nh d\u1ea5u l\u00ean th\u00e2n c\u1ecdc ph\u1ee5 (chi\u1ec1u s\u00e2u n\u00e0y thay \u0111\u1ed5i theo t\u1eebng v\u1ecb tr\u00ed m\u1eb7t \u0111\u1ea5t c\u1ee7a \u0111\u00e0i m\u00e0 ta \u0111\u1eb7t d\u1ea7m th\u00e9p c\u1ee7a m\u00e1y \u00e9p c\u1ecdc). Ti\u1ebfn h\u00e0nh thi c\u00f4ng c\u1ecdc ph\u1ee5 nh\u01b0ng c\u1ecdc ch\u00ednh t\u1edbi chi\u1ec1u s\u00e2u \u0111\u00e3 v\u1ea1ch s\u1eb5n tr\u00ean th\u00e2n c\u1ecdc ph\u1ee5 \u2022 \u01afu \u0111i\u1ec3m: kh\u00f4ng ph\u1ea3i d\u00f9ng c\u1ecdc \u00e9p \u00e2m nh\u01b0ng ph\u1ea3i ch\u1ebf t\u1ea1o th\u00ea s\u1ed1 m\u00e9t d\u00e0i c\u1ecdc BTCT l\u00e0m c\u1ecdc d\u1eabn, thi c\u00f4ng xong s\u1ebd \u0111\u1eadp \u0111i g\u00e2y t\u1ed1n k\u00e9m, hi\u1ec7u qu\u1ea3 kinh t\u1ebf kh\u00f4ng cao.<\/p>\n
2\/ Ph\u01b0\u01a1ng ph\u00e1p 2: Ph\u01b0\u01a1ng ph\u00e1p \u00e9p \u00e2m \u2022 Ph\u01b0\u01a1ng ph\u00e1p n\u00e0y d\u00f9ng m\u1ed9t \u0111o\u1ea1n c\u1ecdc d\u00e3n \u0111\u1ec3 \u00e9p c\u1ecdc xu\u1ed1ng c\u1ed1t \u00e2m thi\u1ebft k\u1ebf sau \u0111\u00f3 l\u1ea1i r\u00fat c\u1ecdc d\u1eabn l\u00ean \u00e9p cho c\u1ecdc kh\u00e1c, c\u1ea5u t\u1ea1o c\u1ecdc \u00e9p \u00e2m do c\u00e1n b\u1ed9 thi c\u00f4ng thi\u1ebft k\u1ebf v\u00e0 ch\u1ebf t\u1ea1o. \u2022 C\u1ecdc \u00e9p \u00e2m c\u00f3 th\u1ec3 l\u00e0 b\u1eb1ng BTCT ho\u1eb7c th\u00e9p \u2022 V\u00ec h\u00e0nh tr\u00ecnh c\u1ee7a pit\u00f4ng m\u00e1y \u00e9p ch\u1ec9 \u00e9p \u0111\u01b0\u1ee3c c\u00e1ch m\u1eb7t \u0111\u1ea5t t\u1ef1 nhi\u00ean kho\u1ea3ng 0,6 \u2013 0,7m, do v\u1eady chi\u1ec1u d\u00e0i c\u1ecdc \u0111\u01b0\u1ee3c l\u1ea5y t\u1eeb cao tr\u00ecnh \u0111\u1ec9nh c\u1ecdc trong \u0111\u00e0i \u0111\u1ebfn m\u1eb7t \u0111\u1ea5t t\u1ef1 nhi\u00ean c\u1ed9ng th\u00e2m m\u1ed9t \u0111o\u1ea1n 0,7m l\u00e0 h\u00e0nh tr\u00ecnh pit\u00f4ng nh\u01b0 tr\u00ean, c\u00f3 th\u1ec3 l\u1ea5y ra th\u00eam 0,5m n\u1eefa gi\u00fap thao t\u00e1c \u00e9p d\u1ec5 d\u00e0ng h\u01a1n. \u2022 \u01afu \u0111i\u1ec3m: Kh\u00f4ng ph\u1ea3i d\u00f9ng c\u1ecdc ph\u1ee5 BTCT, hi\u1ec7u qu\u1ea3 kinh t\u1ebf cao h\u01a1n, c\u1ecdc d\u1eabn l\u00fac n\u00e0y tr\u1edf th\u00e0nh c\u1ecdc c\u00f4ng c\u1ee5 trong vi\u1ec7c h\u1ea1 c\u1ecdc xu\u1ed1ng c\u1ed1t \u00e2m thi\u1ebft k\u1ebf. \u2022 Nh\u01b0\u1ee3c \u0111i\u1ec3m: thao t\u00e1c v\u1edbi c\u1ecdc d\u1eabn ph\u1ea3i th\u1eadn tr\u1ecdng tr\u00e1nh l\u00e0m nghi\u00eang \u0111\u1ea7u c\u1ecdc ch\u00ednh v\u00ec c\u1ecdc d\u1eabn ch\u1ec9 li\u00ean k\u1ebft kh\u1edbp t\u1ea1m th\u1eddi v\u1edbi \u0111\u1ea7u c\u1ecdc ch\u00ednh (ch\u1ee5p m\u0169 \u0111\u1ea7u c\u1ecdc l\u00ean \u0111\u1ea7u c\u1ecdc). Vi\u1ec7c thi c\u00f4ng nh\u1eefng c\u00f4ng tr\u00ecnh c\u00f3 t\u1ea7ng h\u1ea7m, \u0111\u1ed9 s\u00e2u \u0111\u00e1y \u0111\u00e0i l\u1edbn h\u01a1n thi c\u00f4ng d\u1eabn kh\u00f3 h\u01a1n, khi \u00e9p xong r\u00fat c\u1ecdc l\u00ean kh\u00f3 kh\u0103n h\u01a1n, nhi\u1ec1u tr\u01b0\u1eddng h\u1ee3p c\u1ecdc \u00e9p ch\u00ednh b\u1ecb nghi\u00eang.
4. KINH NGHI\u1ec6M KHI B\u00d3C KH\u1ed0I L\u01af\u1ee2NG D\u1ef0 TO\u00c1N ( Ph\u1ea7n 4 ) C\u00c1C QUY \u0110\u1ecaNH CHUNG TRONG \u0110\u1ecaNH M\u1ee8C D\u1ef0 TO\u00c1N X\u00c2Y D\u1ef0NG C\u00d4NG TR\u00ccNH PH\u1ea6N X\u00c2Y D\u1ef0NG – (C\u00f4ng b\u1ed1 k\u00e8m theo v\u0103n b\u1ea3n s\u1ed1 1776\/BXD- VP ng\u00e0y 16- 8- 2007 c\u1ee7a BXD) .<\/p>\n
1\/ Chi\u1ec1u cao thi c\u00f4ng trong \u0111\u1ecbnh m\u1ee9c l\u00e0 chi\u1ec1u cao t\u00ednh t\u1eeb c\u1ed1t = \u00b10.000 v\u00e0 ph\u00e2n bi\u1ec7t th\u00e0nh c\u00e1c tr\u01b0\u1eddng h\u1ee3p sau: T\u1eeb c\u1ed1t \u00b10.000 \u0111\u1ebfn =4m; T\u1eeb c\u1ed1t =\u00b10.000 \u0111\u1ebfn =16m; T\u1eeb c\u1ed1t \u00b10.000 \u0111\u1ebfn =50m; T\u1eeb c\u1ed1t \u00b10.000 \u0111\u1ebfn >50m Nh\u1eefng c\u00f4ng vi\u1ec7c kh\u00f4ng ph\u00e2n bi\u1ec7t \u0111\u1ed9 cao thi c\u00f4ng nh\u01b0 c\u00f4ng t\u00e1c tr\u00e1t, l\u00e1ng, \u1ed1p v.v. khi thi c\u00f4ng \u1edf \u0111\u1ed9 cao >16m \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng \u0111\u1ecbnh m\u1ee9c b\u1ed1c x\u1ebfp v\u1eadn chuy\u1ec3n v\u1eadt li\u1ec7u l\u00ean cao<\/p>\n
2\/ C\u00f4ng t\u00e1c khoan t\u1ea1o l\u1ed7 cho c\u1ecdc khoan nh\u1ed3i: Khi khoan t\u1ea1o l\u1ed7 cho c\u1ecdc khoan nh\u1ed3i v\u00e0o \u0111\u00e1 \u0111\u1eb7c bi\u1ec7t theo ph\u00e2n lo\u1ea1i trong \u0111\u1ecbnh m\u1ee9c (nh\u00f3m 1 1 v\u00e0 nh\u00f3m 12) th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng nh\u01b0 khoan c\u1ecdc nh\u1ed3i \u0111\u00e1 c\u1ea5p 1 nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,35 theo t\u1eebng lo\u1ea1i \u0111\u1ecbnh m\u1ee9c t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
3\/ C\u00f4ng t\u00e1c ch\u1eb7t c\u00e2y, t\u1ea1o m\u1eb7t b\u1eb1ng x\u00e2y d\u1ef1ng: Tr\u01b0\u1eddng h\u1ee3p ch\u1eb7t \u1edf ch\u1ed7 l\u1ea7y l\u1ed9i th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=2<\/p>\n
4\/ C\u00f4ng t\u00e1c \u0111\u00e0o \u0111\u1eafp \u0111\u1ea5t, \u0111\u00e1 c\u00e1t: – \u0110\u1ecbnh m\u1ee9c \u0111\u00e0o \u0111\u1ea5t \u0111\u01b0\u1ee3c t\u00ednh cho lm3 \u0111\u00e0o \u0111\u1ea5t nguy\u00ean th\u1ed5 t\u1ea1i n\u01a1i \u0111\u00e0o – \u0110\u1ecbnh m\u1ee9c \u0111\u1eafp \u0111\u1ea5t \u0111\u01b0\u1ee3c t\u00ednh cho lm3 \u0111\u1ea5t \u0111\u1eafp theo \u0111\u1ed9 ch\u1eb7t thi\u1ebft k\u1ebf t\u1ea1i n\u01a1i \u0111\u1eafp. – Khi \u0111\u00e0o \u0111\u1ec3 \u0111\u1eafp th\u00ec kh\u1ed1i l\u01b0\u1ee3ng \u0111\u1ea5t \u0111\u00e0o b\u1eb1ng kh\u1ed1i l\u01b0\u1ee3ng \u0111\u1ea5t \u0111\u1eafp nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 chuy\u1ec3n \u0111\u1ed5i K K=l,07 khi h\u1ec7 s\u1ed1 \u0111\u1ea7m n\u00e9n l\u00e0 0,85; dung tr\u1ecdng \u0111\u1ea5t \u0111\u1ea1t \u03b3=l,45 T\/ m3 \u2013 l,6 T\/ m3 K=l,l khi h\u1ec7 s\u1ed1 \u0111\u1ea7m n\u00e9n l\u00e0 0,9; dung tr\u1ecdng \u0111\u1ea5t \u0111\u1ea1t \u03b3=l,75 T\/ m3 K=l,13 khi h\u1ec7 s\u1ed1 \u0111\u1ea7m n\u00e9n l\u00e0 0,95; dung tr\u1ecdng \u0111\u1ea5t \u0111\u1ea1t \u03b3=l,8 T\/ m3 K=l,16 khi h\u1ec7 s\u1ed1 d\u1ea7m n\u00e9n l\u00e0 0,98; dung tr\u1ecdng \u0111\u1ea5t \u0111\u1ea1t \u03b3=l,8 T\/ m3 Ri\u00eang kh\u1ed1i l\u01b0\u1ee3ng \u0111\u00e1 h\u1ed7n h\u1ee3p c\u1ea7n \u0111\u00e0o \u0111\u1ec3 \u0111\u1eafp th\u00ec h\u1ec7 s\u1ed1 chuy\u1ec3n \u0111\u1ed5i K=l,13.<\/p>\n
5\/ Khi c\u1ef1 ly v\u1eadn chuy\u1ec3n \u0111\u1ea5t \u0111\u00e1 b\u1eb1ng \u00d4 t\u00f4 t\u1ef1 \u0111\u1ed5 \u0111\u00e3 t\u00ednh \u0111\u1ebfn h\u1ec7 s\u1ed1 t\u01a1i c\u1ee7a \u0111\u1ea5t, \u0111\u00e1 \u0111\u00e3 \u0111\u01b0a v\u00e0o \u0111\u1ecbnh m\u1ee9c v\u1edbi c\u00e1c c\u1ef1 ly: L=300m; L=500m; L=700m; L=1000m. Khi v\u1eadn chuy\u1ec3n v\u1edbi c\u1ef1 ly >1000m th\u00ec s\u1eed d\u1ee5ng \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n cho 1000m v\u00e0 \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n cho 1000m ti\u1ebfp theo theo c\u00e1ch chuy\u1ec3n \u0111\u1ed5i nh\u01b0 sau: + \u0110\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n v\u1edbi c\u1ef1 ly L=2km th\u00ec \u0110M= \u0110M l+ \u0110M 2x(l- l) + \u0110\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n v\u1edbi c\u1ef1 ly L=4km th\u00ec \u0110m= \u0110M l+ \u0110M 3x(l- l) + \u0110\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n v\u1edbi c\u1ef1 ly L=7km th\u00ec \u0110M = \u0110M l+ \u0110M 4x(l- l) Trong \u0111\u00f3 v\u1eadn chuy\u1ec3n v\u1edbi c\u1ef1 ly L>7km th\u00ec \u0110M=\u0110M1+\u0110M4x6+\u0110M5x(L- 7) \u0110M1: \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n trong ph\u1ea1m vi =1000m \u0110M2: \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n trong ph\u1ea1m vi =2km \u0110M3: \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n trong ph\u1ea1m vi =4km \u0110M4: \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n trong ph\u1ea1m vi =7km \u0110M5: \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n trong ph\u1ea1m vi >7km
6\/ C\u00f4ng t\u00e1c \u0111\u00e0o – \u0110\u00e0o, x\u00fac \u0111\u1ea5t h\u1eefu c\u01a1 , \u0111\u1ea5t phong h\u00f3a b\u1eb1ng m\u00e1y \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng nh\u01b0 \u0111\u1ecbnh m\u1ee9c \u0111\u00e0o \u0111\u1ea5t t\u1ea1o m\u1eb7t b\u1eb1ng \u2013 \u0111\u1ea5t c\u1ea5p 1 – C\u00f4ng t\u00e1c \u0111\u00e0o \u0111\u1ea5t \u0111\u1ec3 \u0111\u1eb7t \u0111\u01b0\u1eddng \u1ed1ng, \u0111\u01b0\u1eddng c\u00e1p trong th\u00e0nh ph\u1ed1, th\u1ecb tr\u1ea5n th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,2 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u0111\u00e0o \u0111\u1ea5t t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
7\/ \u0110\u1eafp \u0111\u1ea5t n\u1ec1n \u0111\u01b0\u1eddng, b\u1edd k\u00eanh m\u01b0\u01a1ng khi m\u1edf r\u1ed9ng th\u00ec hao ph\u00ed nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,15 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u0111\u1eafp n\u1ec1n \u0111\u01b0\u1eddng, \u0111\u1eafp b\u1edd k\u00eanh m\u01b0\u01a1ng t\u01b0\u01a1ng \u1ee9ng. 8\/ \u0110\u00e0o m\u00f3ng c\u00f4ng tr\u00ecnh, \u0111\u00e0o k\u00eanh m\u01b0\u01a1ng, n\u1ec1n \u0111\u01b0\u1eddng tr\u00ean n\u1ec1n \u0111\u1ea5t y\u1ebfu b\u1eb1ng t\u1ed5 h\u1ee3p 2;3;4 m\u00e1y \u0111\u00e0o N\u1ebfu ph\u1ea3i s\u1eed d\u1ee5ng c\u00e1c t\u1ea5m ch\u1ed1ng l\u1ea7y s\u1ee5t trong thi c\u00f4ng th\u00ec \u0111\u1ecbnh m\u1ee9c hao ph\u00ed ca m\u00e1y \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,15. Chi ph\u00ed v\u1eadt li\u1ec7u t\u1ea5m ch\u1ed1ng l\u1ea7y s\u1ee5t \u0111\u01b0\u1ee3c t\u00ednh ri\u00eang trong d\u1ef1 to\u00e1n.<\/p>\n
9\/ N\u1ea1o v\u00e9t ho\u1eb7c m\u1edf r\u1ed9ng k\u00eanh m\u01b0\u01a1ng tr\u00ean n\u1ec1n \u0111\u1ea5t m\u1ec1m y\u1ebfu b\u1eb1ng t\u1ed5 h\u1ee3p m\u00e1y c\u1ea1p v\u00e0 m\u00e1y \u0111\u00e0o, n\u1ebfu ph\u1ea3i s\u1eed d\u1ee5ng c\u00e1c t\u1ea5m ch\u1ed1ng l\u1ea7y s\u1ee5t th\u00ec \u0111\u1ecbnh m\u1ee9c hao ph\u00ed ca m\u00e1y \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 1,15. Hao ph\u00ed v\u1eadt li\u1ec7u d\u00f9ng \u0111\u1ec3 ch\u1ed1ng l\u1ea7y s\u1ee5t \u0111\u01b0\u1ee3c t\u00ednh ri\u00eang v\u00e0o d\u1ef1 to\u00e1n.<\/p>\n
10\/ Ph\u00e1 \u0111\u00e1 h\u1ed1 m\u00f3ng c\u00f4ng tr\u00ecnh n\u1ec1n \u0111\u01b0\u1eddng, k\u00eanh m\u01b0\u01a1ng, khoan n\u1ed5 m\u00ecn. Khi khoan n\u1ed5 t\u1ea7ng ti\u1ebfp gi\u00e1p v\u1edbi l\u1edbp b\u1ea3o v\u1ec7 \u0111\u00e1y h\u1ed1 m\u00f3ng th\u00ec hao ph\u00ed v\u1eadt li\u1ec7u, nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,2.<\/p>\n
11\/ \u0110\u00e0o h\u1ea7m, gi\u1ebfng \u0111\u1ee9ng, gi\u1ebfng nghi\u00eang (chi\u1ec1u cao \u0111\u00e0o =50m). Khi chi\u1ec1u cao \u0111\u00e0o h\u1ea7m, gi\u1ebfng >50m th\u00ec \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,2 v\u00e0 hao ph\u00ed ca m\u00e1y \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,05.<\/p>\n
12\/ C\u00f4ng t\u00e1c ph\u00e1 \u0111\u00e1 d\u01b0\u1edbi n\u01b0\u1edbc: Khi khoan n\u1ed5 m\u00ecn, ph\u00e1 \u0111\u00e1 d\u01b0\u1edbi n\u01b0\u1edbc \u1edf \u0111\u1ed9 s\u00e2u t\u1eeb m\u1eb7t n\u01b0\u1edbc >7m th\u00ec \u0111\u1ecbnh m\u1ee9c hao ph\u00ed v\u1eadt li\u1ec7u, nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,1 . N\u1ebfu \u0111\u1ed9 s\u00e2u t\u1eeb m\u1eb7t n\u01b0\u1edbc <3m th\u00ec \u0111\u1ecbnh m\u1ee9c hao ph\u00ed v\u1eadt li\u1ec7u, nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=0,9 so v\u1edbi \u0111\u1ecbnh m\u1ee9c n\u1ed5 m\u00ecn d\u01b0\u1edbi n\u01b0\u1edbc v\u1edbi chi\u1ec1u s\u00e2u quy \u0111\u1ecbnh trong \u0111\u1ecbnh m\u1ee9c (3m- 7m)<\/p>\n
13\/ C\u00f4ng t\u00e1c \u0111\u1eafp c\u00e1t t\u1ea1o m\u1eb7t b\u1eb1ng c\u00f4ng tr\u00ecnh kh\u00f4ng y\u00eau c\u1ea7u \u0111\u1ea7m ch\u1eb7t th\u00ec hao ph\u00ed nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=0,85 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u0111\u1eafp c\u00e1t c\u00f4ng tr\u00ecnh v\u1edbi \u0111\u1ed9 \u0111\u1ea7m n\u00e9n .K=0,85.<\/p>\n
14\/ C\u00f4ng t\u00e1c n\u1ea1o v\u00e9t c\u00e1c c\u00f4ng tr\u00ecnh th\u1ee7y: + Khi n\u1ea1o v\u00e9t c\u00f4ng tr\u00ecnh th\u1ee7y \u1edf v\u00f9ng \u00e2u t\u00e0u, v\u00f9ng quay t\u00e0u, c\u00e1c c\u1ea3ng ra v\u00e0o \u0111ang khai th\u00e1c th\u00ec \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,1 so v\u1edbi \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t b\u1eb1ng c\u00e1c kh\u1ed1i t\u00e0u t\u01b0\u01a1ng \u1ee9ng + Khi n\u1ea1o v\u00e9t \u1edf n\u01a1i th\u01b0\u1eddng xuy\u00ean c\u00f3 s\u00f3ng l\u1edbn quanh n\u0103m, s\u1ef1 b\u1ed3i \u0111\u1eafp c\u1ee5c b\u1ed9 m\u1ea1nh, kh\u1ea3 n\u0103ng r\u1ee7i ro l\u1edbn \u1edf c\u00e1c khu v\u1ef1c c\u1eeda bi\u1ec3n \u0110\u1ecbnh An, c\u1eeda \u0110\u00e1y, c\u1eeda H\u1ed9i, c\u1eeda Vi\u1ec7t, L\u1ec7 M\u00f4n, Di\u00eam \u0110i\u1ec1n ho\u1eb7c khu v\u1ef1c tr\u1ef1c ti\u1ebfp ch\u1ecbu \u1ea3nh h\u01b0\u1edfng c\u1ee7a s\u00f3ng = c\u1ea5p 3 ho\u1eb7c n\u01a1i c\u00f3 d\u00f2ng ch\u1ea3y th\u01b0\u1eddng xuy\u00ean >2m\/s th\u00ec \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,2 so v\u1edbi \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t b\u1eb1ng c\u00e1c kh\u1ed1i t\u00e0u t\u01b0\u01a1ng \u1ee9ng. + Khi n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u h\u00fat m\u00e0 chi\u1ec1u s\u00e2u n\u1ea1o v\u00e9t s\u00e2u th\u00eam 1m ho\u1eb7c chi\u1ec1u cao \u1ed1ng x\u1ea3 cao h\u01a1n 1m ho\u1eb7c chi\u1ec1u d\u00e0i \u1ed1ng x\u1ea3 d\u00e0i th\u00eam 100m so v\u1edbi c\u00e1c k\u00edch th\u01b0\u1edbc quy \u0111\u1ecbnh trong \u0111\u1ecbnh m\u1ee9c th\u00ec c\u1ee9 t\u0103ng th\u00eam chi\u1ec1u s\u00e2u 1m ho\u1eb7c chi\u1ec1u d\u00e0i 100m \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,07 so v\u1edbi \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u h\u00fat t\u01b0\u01a1ng \u1ee9ng. + Khi n\u1ea1o v\u00e9t \u1edf nh\u1eefng khu v\u1ef1c c\u00f3 chi\u1ec1u d\u00e0y l\u1edbp \u0111\u1ea5t n\u1ea1o v\u00e9t =0,4m th\u00ec \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,05. + Khi n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u cu\u1ed1c (\u0111\u1ed9 s\u00e2u h\u1ea1 g\u1ea7u t\u1eeb 6m- 9m): v\u1edbi \u0111\u1ed9 s\u00e2u h\u1ea1 g\u1ea7u \u0111\u1ed1i v\u1edbi t\u00e0u cu\u1ed1c <6m ho\u1eb7c >9m th\u00ec \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,1 so v\u1edbi \u0111\u1ecbnh m\u1ee9c b\u1eb1ng t\u00e0u v\u00e9t t\u01b0\u01a1ng \u1ee9ng . + Khi n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u cu\u1ed1c \u1edf khu v\u1ef1c c\u00f3 chi\u1ec1u d\u00e0y n\u1ea1o v\u00e9t <0,4m th\u00ec \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t b\u1eb1ng cu\u1ed1c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 1,1 + N\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u h\u00fat b\u1ee5ng t\u1ef1 h\u00e0nh v\u1edbi \u0111\u1ed9 s\u00e2u h\u1ea1 g\u1ea7u quy \u0111\u1ecbnh t\u1eeb 4m \u0111\u1ebfn 6m v\u1edbi t\u00e0u c\u00f3 c\u00f4ng su\u1ea5t =2500CV v\u00e0 t\u1eeb 5m \u0111\u1ebfn 9m \u0111\u1ed1i v\u1edbi t\u00e0u c\u00f3 c\u00f4ng su\u1ea5t 2500CV . N\u1ebfu \u0111\u1ed9 s\u00e2u h\u1ea1 g\u1ea5u <4m ho\u1eb7c >6m \u0111\u1ed1i v\u1edbi t\u00e0u c\u00f4ng su\u1ea5t =2500CV v\u00e0 <5m ho\u1eb7c >9m \u0111\u1ed1i v\u1edbi t\u00e0u c\u00f3 c\u00f4ng su\u1ea5t >2500CV th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,15 so v\u1edbi \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u h\u00fat b\u1ee5ng t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
15\/ Khi n\u1ea1o v\u00e9t k\u00eanh m\u01b0\u01a1ng b\u1eb1ng m\u00e1y \u0111\u00e0o g\u1ea7u d\u00e2y (\u0111\u1ed5 \u0111\u1ea5t 1 b\u00ean): N\u1ea1o v\u00e9t k\u00eanh m\u01b0\u01a1ng \u0111\u1ed5 \u0111\u1ea5t 2 b\u00ean b\u1eb1ng m\u00e1y \u0111\u00e0o g\u1ea5u d\u00e2y th\u00ec \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng v\u00e0 m\u00e1y thi c\u00f4ng ph\u1ea3i nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=0,85 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u0111\u1ed5 \u0111\u1ea5t 1 b\u00ean.<\/p>\n
16\/ Khi n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u \u0111\u00e0o g\u1ea7u ngo\u1ea1m (\u0111\u1ecbnh m\u1ee9c v\u1edbi chi\u1ec1u s\u00e2u d\u00e0o 9m- 15m): V\u1edbi \u0111\u1ed9 s\u00e2u \u0111\u00e0o t\u1eeb > 15m \u0111\u1ebfn 20m th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,25 ; v\u1edbi \u0111\u1ed9 s\u00e2u >20m th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,35 so v\u1edbi \u0111\u1ecbnh m\u1ee9c n\u1ea1o v\u00e9t b\u1eb1ng t\u00e0u t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
17\/ Khi \u0111\u00e0o ph\u00e1 \u0111\u00e1, b\u1ed1c x\u00fac \u0111\u00e1 d\u01b0\u1edbi n\u01b0\u1edbc b\u1eb1ng t\u00e0u \u0111\u00e0o (\u0111\u1ed9 s\u00e2u =10m): Tr\u01b0\u1eddng h\u1ee3p ph\u00e1 \u0111\u00e1 ng\u1ea7m \u1edf \u0111\u1ed9 s\u00e2u m\u1ef1c n\u01b0\u1edbc >l0m- 20m th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,25; v\u1edbi \u0111\u1ed9 s\u00e2u >20m \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,35 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u0111\u00e0o \u0111\u00e1 v\u00e0 b\u1ed1c x\u00fac \u0111\u00e1 t\u01b0\u01a1ng’ \u1ee9ng.<\/p>\n
18\/ V\u1eadn chuy\u1ec3n \u0111\u1ea5t, c\u00e1t \u0111\u1ed5 \u0111i 1km ti\u1ebfp theo ngo\u00e0i 6km \u0111\u1ea7u b\u1eb1ng t\u00e0u h\u00fat b\u1ee5ng t\u1ef1 h\u00e0nh (\u0111\u1ecbnh m\u1ee9c t\u1eeb 6- 20Km): Tr\u01b0\u1eddng h\u1ee3p v\u1eadn chuy\u1ec3n ngo\u00e0i c\u1ef1 ly 20km (>20km) th\u00ec \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n 1Km ti\u1ebfp theo t\u1eeb Km21 tr\u1edf \u0111i ch\u1ec9 t\u00ednh b\u1eb1ng 70% \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n 1km ti\u1ebfp theo t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
19\/ C\u00f4ng t\u00e1c \u0111\u00f3ng c\u1ecdc, \u00e9p c\u1ecdc, nh\u1ed5 c\u1ecdc,khoan t\u1ea1o l\u1ed7 c\u1ecdc khoan nh\u1ed3i + \u0110\u1ecbnh m\u1ee9c \u0111\u00f3ng c\u1ecdc quy \u0111\u1ecbnh cho 100m c\u1ecdc ng\u1eadp \u0111\u1ea5t. N\u1ebfu c\u00f3 \u0111o\u1ea1n kh\u00f4ng ng\u1eadp \u0111\u1ea5t th\u00ec hao ph\u00ed nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng c\u1ee7a \u0111o\u1ea1n c\u1ecdc kh\u00f4ng ng\u1eadp \u0111\u1ea5t ph\u1ea3i nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=0,75 so v\u1edbi \u0111\u1ecbnh m\u1ee9c c\u1ee7a c\u1ecdc t\u01b0\u01a1ng \u1ee9ng. + Khi \u0111\u00f3ng c\u1ecdc, \u00e9p c\u1ecdc xi\u00ean th\u00ec \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,22 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u0111\u00f3ng c\u1ecdc t\u01b0\u01a1ng \u1ee9ng. + Khi ph\u1ea3i d\u00f9ng c\u1ecdc d\u1eabn \u0111\u1ec3 \u0111\u00f3ng c\u1ecdc \u00e2m th\u00ec \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l ,05 (trong \u0111\u1ecbnh m\u1ee9c ch\u01b0a t\u00ednh \u0111\u1ebfn ph\u1ea7n gia c\u00f4ng ch\u1ebf t\u1ea1o c\u1ecdc d\u1eabn) + \u0110\u1ecbnh m\u1ee9c \u0111\u00f3ng c\u1ecdc b\u1eb1ng m\u00e1y tr\u00ean m\u1eb7t n\u01b0\u1edbc ch\u01b0a t\u00ednh \u0111\u1ebfn c\u00f4ng t\u00e1c l\u00e0m s\u00e0n \u0111\u1ea1o, x\u00e0 k\u1eb9p, phao n\u1ed5i, Hao ph\u00ed v\u1eadt li\u1ec7u kh\u00e1c \u0111\u00e3 t\u00ednh \u0111\u1ebfn hao ph\u00ed v\u1eadt li\u1ec7u \u0111\u1ec7m \u0111\u1ea7u c\u1ecdc, ch\u1ee5p \u0111\u1ea7u c\u1ecdc.\u00a0+ C\u1ea5p \u0111\u1ea5t quy \u0111\u1ecbnh \u0111\u1ec3 \u00e1p d\u1ee5ng \u0111\u1ecbnh m\u1ee9c nh\u01b0 sau: * N\u1ebfu chi\u1ec1u s\u00e2u l\u1edbp \u0111\u1ea5t c\u1ea5p 1 chi\u1ebfm =60% chi\u1ec1u d\u00e0i c\u1ecdc ng\u1eadp \u0111\u1ea5t th\u00ec \u00e1p d\u1ee5ng \u0111\u00f3ng c\u1ecdc v\u1edbi \u0111\u1ea5t c\u1ea5p 1 * N\u1ebfu \u0111\u1ed9 s\u00e2u l\u1edbp \u0111\u1ea5t c\u1ea5p 1 chi\u1ebfm <40% chi\u1ec3u d\u00e0i c\u1ecdc ng\u1eadp \u0111\u1ea5t th\u00ec \u00e1p d\u1ee5ng \u0111\u00f3ng c\u1ecdc v\u1edbi \u0111\u1ea5t c\u1ea5p 2. + Khi \u0111\u00f3ng c\u1ecdc, \u00e9p c\u1ecdc ph\u1ea3i khoan d\u1eabn, \u0111\u1ecbnh m\u1ee9c \u00e1p d\u1ee5ng cho \u0111o\u1ea1n c\u1ecdc qua chi\u1ec1u s\u00e2u khoan d\u1eabn l\u1ea5y b\u1eb1ng \u0111\u1ecbnh m\u1ee9c \u0111\u00f3ng, \u00e9p c\u1ecdc v\u00e0o \u0111\u1ea5t c\u1ea5p 1 (c\u00f4ng t\u00e1c khoan d\u1eabn ch\u01b0a t\u00ednh trong \u0111\u1ecbnh m\u1ee9c) + C\u00f4ng t\u00e1c \u0111\u00f3ng c\u1ecdc \u1ed1ng ch\u01b0a t\u00ednh \u0111\u1ebfn hao ph\u00ed cho vi\u1ec7c x\u00f3i, h\u00fat h\u1ed7n h\u1ee3p b\u00f9n \u0111\u1ea5t trong l\u00f2ng c\u1ecdc.<\/p>\n
20\/ C\u00f4ng t\u00e1c \u0111\u00f3ng c\u1ecdc v\u00e1n th\u00e9p, c\u1ecdc \u1ed1ng th\u00e9p, c\u1ecdc th\u00e9p h\u00ecnh cho tr\u01b0\u1eddng h\u1ee3p l\u00e0 c\u1ecdc n\u1eb1m l\u1ea1i trong c\u00f4ng tr\u00ecnh. Tr\u01b0\u1eddng h\u1ee3p c\u1ecdc \u0111\u01b0\u1ee3c nh\u1ed5 l\u00ean s\u1eed d\u1ee5ng nhi\u1ec1u l\u1ea7n th\u00ec chi ph\u00ed v\u1eadt li\u1ec7u c\u1ecdc \u0111\u01b0\u1ee3c t\u00ednh cho m\u1ed9t l\u1ea7n \u0111\u00f3ng, nh\u1ed5 nh\u01b0 sau: + Khi th\u1eddi gian c\u1ecdc n\u1eb1m trong c\u00f4ng tr\u00ecnh = 1 th\u00e1ng th\u00ec chi ph\u00ed v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c t\u00ednh l\u00e0 1,17 % so v\u1edbi gi\u00e1 tr\u1ecb c\u1ee7a c\u1ecdc + Khi th\u1eddi gian c\u1ecdc n\u1eb1m trong c\u00f4ng tr\u00ecnh t\u1eeb th\u00e1ng th\u1ee9 2 tr\u1edf \u0111i th\u00ec c\u1ee9 m\u1ed7i th\u00e1ng hao ph\u00ed v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c t\u00ednh th\u00eam l\u00e0: * C\u1ecdc \u0111\u00f3ng tr\u00ean c\u1ea1n hay trong m\u00f4i tr\u01b0\u1eddng n\u01b0\u1edbc ng\u1ecdt \u0111\u01b0\u1ee3c l\u1ea5y b\u1eb1ng 1,17% m\u1ed9t th\u00e1ng * N\u1ebfu c\u1ecdc n\u1eb1m trong m\u00f4i tr\u01b0\u1eddng n\u01b0\u1edbc l\u1ee3 \u0111\u01b0\u1ee3c l\u1ea5y b\u1eb1ng 1 ,22% th\u00e1ng + C\u1ea5p \u0111\u1ea5t quy \u0111\u1ecbnh \u0111\u1ec3 \u00e1p d\u1ee5ng \u0111\u1ecbnh m\u1ee9c nh\u01b0 sau: * Hao h\u1ee5t s\u1ee9t m\u1ebb, t\u00f2e \u0111\u1ea7u c\u1ecdc, m\u0169i c\u1ecdc (t\u00ednh cho 1 l\u1ea7n \u0111\u00f3ng nh\u1ed5) * \u0110\u00f3ng c\u1ecdc \u1edf \u0111\u1ea5t c\u1ea5p I,II hao h\u1ee5t l\u1ea5y l\u00e0 3,5%\/1 l\u1ea7n \u0111\u00f3ng nh\u1ed5 * \u0110\u00f3ng c\u1ecdc v\u00e0o \u0111\u1ea5t \u0111\u00e1 c\u00f3 \u1ee9ng su\u1ea5t =5kg\/cm2 th\u00ec hao h\u1ee5t l\u1ea5y b\u1eb1ng 4,5%\/1l\u1ea7n \u0111\u00f3ng nh\u1ed5 * Khi c\u1ecdc kh\u00f4ng nh\u1ed5 \u0111\u01b0\u1ee3c ph\u1ea3i c\u1eaft b\u1ecf, th\u00ec ph\u1ea7n c\u1ecdc c\u00f2n l\u1ea1i n\u1eb1m trong c\u00f4ng tr\u00ecnh \u0111\u01b0\u1ee3c t\u00ednh 100% gi\u00e1 tr\u1ecb kh\u1ed1i l\u01b0\u1ee3ng c\u1ecdc ph\u1ea3i n\u1eb1m l\u1ea1i trong c\u00f4ng tr\u00ecnh.<\/p>\n
21\/ C\u00f4ng t\u00e1c khoan c\u1ecdc nh\u1ed3i: + Khoan c\u1ecdc nh\u1ed3i khi c\u00f3 c\u00e1c \u0111i\u1ec1u ki\u1ec7n kh\u00e1c v\u1edbi quy \u0111\u1ecbnh trong \u0111\u1ecbnh m\u1ee9c th\u00ec \u0111\u1ecbnh m\u1ee9c \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 \u0111i\u1ec1u ch\u1ec9nh nh\u01b0 sau: * \u0110\u1ed9 s\u00e2u khoan >30m th\u00ec t\u1eeb m\u00e9t khoan th\u1ee9 31 tr\u1edf \u0111i K=l,015 * Khoan \u1edf n\u01a1i c\u00f3 d\u00f2ng ch\u1ea3y >2m\/s l\u1ea5y K= 1,1 * Khoan t\u1ea1i c\u1ea3ng \u0111ang ho\u1ea1t \u0111\u1ed9ng, c\u1eeda s\u00f4ng, c\u1eeda bi\u1ec3n, h\u1ea3i \u0111\u1ea3o l\u1ea5y K=l,2′ * Khoan xi\u00ean v\u00e0o \u0111\u1ea5t l\u1ea5y K=l,2 * Khoan xi\u00ean v\u00e0o \u0111\u00e1 l\u1ea5y K=l,3 * Khoan d\u01b0\u1edbi n\u01b0\u1edbc v\u1edbi m\u1ef1c n\u01b0\u1edbc s\u00e2u h\u01a1n 4m th\u00ec c\u1ee9 im m\u1ef1c n\u01b0\u1edbc s\u00e2u th\u00eam K=l,05 * Khoan \u1edf khu v\u1ef1c c\u00f3 th\u1ee7y tri\u1ec1u m\u1ea1nh, ch\u00eanh l\u1ec7ch m\u1ef1c n\u01b0\u1edbc th\u1ee7y tri\u1ec1u gi\u1eefa l\u00ean xu\u1ed1ng >l,5m th\u00ec c\u1ee9 1m ch\u00eanh l\u1ec7ch m\u1ef1c n\u01b0\u1edbc K=l,05 * Khoan c\u00f3 \u1ed1ng v\u00e1ch ph\u1ee5 v\u1edbi chi\u1ec1u d\u00e0i >30% chi\u1ec1u d\u00e0i c\u1ecdc K=l,l * Khoan ng\u00e0m \u0111\u00e1 > 1 l\u1ea7n \u0111\u01b0\u1eddng k\u00ednh c\u1ecdc th\u00ec c\u1ee9 1m khoan s\u00e2u th\u00eam K =l,2 * Khoan v\u00e0o \u0111\u1ea5t s\u00e9t d\u1ebbo, s\u00e9t c\u1ee9ng, c\u00e1t ch\u1eb7t, \u0111\u1ea5t l\u1eabn cu\u1ed9i s\u1ecfi c\u00f3 k\u00edch th\u01b0\u1edbc \u0111\u1ebfn = 10 cm K=1,2\u00a0+ C\u00f4ng t\u00e1c t\u1ea1o l\u1ed7 c\u1ecdc, t\u01b0\u1eddng Barret: Khi t\u1ea1o l\u1ed7 \u1edf \u0111\u1ed9 s\u00e2u >30m th\u00ec t\u1eeb m\u00e9t th\u1ee9 31 tr\u1edf \u0111i \u0111\u1ecbnh m\u1ee9c\u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,015<\/p>\n
22\/ C\u00f4ng t\u00e1c l\u00e0m m\u1eb7t \u0111\u01b0\u1eddng \u0111\u00e1 d\u0103m, m\u1eb7t \u0111\u01b0\u1eddng c\u1ea5p ph\u1ed1i: Khi chi\u1ec1u d\u00e0y m\u1eb7t \u0111\u01b0\u1eddng kh\u00e1c v\u1edbi chi\u1ec1u d\u00e0y \u0111\u1ecbnh m\u1ee9c quy \u0111\u1ecbnh th\u00ec s\u1eed d\u1ee5ng \u0111\u1ecbnh m\u1ee9c l\u00e0m l\u1edbp d\u01b0\u1edbi \u0111\u1ec3 n\u1ed9i suy.<\/p>\n
23\/ C\u00f4ng t\u00e1c l\u1eafp c\u1ed9t th\u00f4ng tin t\u00edn hi\u1ec7u: + N\u1ebfu l\u1eafp c\u1ed9t \u1edf n\u01a1i l\u1ea7y l\u1ed9i, \u0111\u1ed3i n\u00fai, ao h\u1ed3 th\u00ec \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,2. + N\u1ebfu v\u1eadn chuy\u1ec3n c\u1ed9t >1000m th\u00ec c\u1ee9 50m v\u1eadn chuy\u1ec3n ti\u1ebfp theo \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c c\u1ed9ng th\u00eam 0,79 c\u00f4ng\/1c\u1ed9t<\/p>\n
24\/ C\u00f4ng t\u00e1c x\u00e2y g\u1ea1ch ch\u1ecbu l\u1eeda: + Khi m\u1ea1ch v\u1eefa theo theo thi\u1ebft k\u1ebf =l,5mm th\u00ec hao ph\u00ed nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=1,l + Khi m\u1ea1ch v\u1eefa >3mm th\u00ec K=0,95 so v\u1edbi \u0111\u1ecbnh m\u1ee9c x\u00e2y g\u1ea1ch ch\u1ecbu l\u1eeda t\u01b0\u01a1ng \u1ee9ng. + C\u00f4ng t\u00e1c v\u1eadn chuy\u1ec3n v\u1eefa b\u00ea t\u00f4ng b\u1eb1ng \u00d4 t\u00f4 chuy\u1ec3n tr\u1ed9n: C\u1ef1 ly v\u1eadn chuy\u1ec3n >4 Km th\u00ec c\u1ee9 th\u00eam 1km v\u1eadn chuy\u1ec3n ti\u1ebfp theo \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n \u1edf c\u1ef1 ly 4 Km c\u1ed9ng v\u1edbi \u0111\u1ecbnh m\u1ee9c v\u1eadn chuy\u1ec3n 1 Km ti\u1ebfp theo<\/p>\n
25\/ \u0110\u1ecbnh m\u1ee9c th\u00e1o, di chuy\u1ec3n h\u1ec7 v\u00e1n khu\u00f4n trong h\u1ea7m: ch\u01b0a t\u00ednh th\u00e1o d\u1ee1 c\u1ea3 t\u1ed5 h\u1ee3p v\u00e1n khu\u00f4n l\u1ea7n cu\u1ed1i c\u00f9ng khi ho\u00e0n th\u00e0nh c\u00f4ng t\u00e1c \u0111\u1ed5 b\u00ea t\u00f4ng.<\/p>\n
26\/ C\u00f4ng t\u00e1c gia c\u00f4ng l\u1eafp d\u1ef1ng v\u00e1n khu\u00f4n m\u1eb7t cong trong c\u00f4ng tr\u00ecnh th\u1ee7y c\u00f4ng ch\u01b0a c\u00f3 trong \u0111\u1ecbnh m\u1ee9c. V\u00ec v\u1eady c\u00f4ng vi\u1ec7c n\u00e0y ph\u1ea3i \u0111\u01b0a v\u00e0o khi l\u1eadp d\u1ef1 to\u00e1n t\u00f9y t heo c\u1ea5u t\u1ea1o thi\u1ebft k\u1ebf<\/p>\n
27\/ C\u00f4ng t\u00e1c s\u1ea3n xu\u1ea5t v\u00e1n khu\u00f4n d\u1ea7m c\u1ea7u b\u1eb1ng c\u00f4ng ngh\u1ec7 \u0111\u00fac h\u1eabng ph\u1ea7n v\u00e1n khu\u00f4n c\u1ee7a h\u1ed9p \u0111\u1ec9nh khi h\u1ee3p long b\u1eaft bu\u1ed9c ph\u1ea3i ch\u00f4n trong b\u00ea t\u00f4ng n\u00ean ph\u1ea7n th\u00e9p n\u00e0y \u0111\u01b0\u1ee3c t\u00ednh v\u00e0o d\u1ef1 to\u00e1n nh\u01b0 c\u00f4ng t\u00e1c gia c\u00f4ng k\u1ebft c\u1ea5u th\u00e9p trong b\u00ea t\u00f4ng.<\/p>\n
28\/ S\u1ea3n xu\u1ea5t khung gi\u00e0n, s\u00e0n \u0111\u1ea1o, s\u00e0n thao t\u00e1c thi c\u00f4ng: Hao ph\u00ed v\u1eadt li\u1ec7u ch\u00ednh nh\u01b0 th\u00e9p h\u00ecnh, th\u00e9p t\u1ea5m, th\u00e9p tr\u00f2n \u0111\u01b0\u1ee3c ph\u00e2n b\u1ed5 v\u00e0o c\u00f4ng t\u00e1c n\u00e0y v\u1edbi m\u1ee9c 2% m\u1ed9t th\u00e1ng. Hao h\u1ee5t t\u00ednh cho m\u1ed9t l\u1ea7n th\u00e1o l\u1eafp l\u00e0 7%<\/p>\n
29\/ C\u00f4ng t\u00e1c th\u00e1o d\u1ee1 khung gi\u00e0n, s\u00e0n \u0111\u1ea1o, gi\u00e1 long m\u00f4n khi thi c\u00f4ng: Hao ph\u00ed v\u1eadt li\u1ec7u, nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng t\u00ednh b\u1eb1ng 60% \u0111\u1ecbnh m\u1ee9c l\u1eafp d\u1ef1ng (chi\u1ebfm trong \u0111\u1ecbnh m\u1ee9c l\u1eafp d\u1ef1ng v\u00e0 th\u00e1o d\u1ee1)<\/p>\n
30\/ C\u00f4ng t\u00e1c tr\u00e1t t\u01b0\u1eddng g\u1ea1ch r\u1ed7ng: \u0110\u1ecbnh m\u1ee9c hao ph\u00ed v\u1eefa t\u0103ng 10% so v\u1edbi \u0111\u1ecbnh m\u1ee9c hao ph\u00ed v\u1eefa cho c\u00f4ng t\u00e1c tr\u00e1t t\u01b0\u1eddng<\/p>\n
31\/ C\u00f4ng t\u00e1c tr\u00e1t x\u00e0, d\u1ea7m, tr\u1ea7n b\u00ea t\u00f4ng: N\u1ebfu y\u00eau c\u1ea7u ph\u1ea3i b\u1ea3 l\u1edbp v\u1eefa xi m\u0103ng b\u00e1m d\u00ednh l\u00ean b\u1ec1 m\u1eb7t tr\u01b0\u1edbc khi tr\u00e1t th\u00ec \u0111\u1ecbnh m\u1ee9c hao ph\u00ed v\u1eadt li\u1ec7u \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,25 ; hao ph\u00ed nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=1,1<\/p>\n
32\/ C\u00f4ng t\u00e1c \u1ed1p \u0111\u00e1 granite, \u0111\u00e1 c\u1ea9m th\u1ea1ch, \u0111\u00e1 hoa c\u01b0\u01a1ng v\u00e0o c\u1ed9t, tr\u1ee5 th\u00ec \u0111\u1ecbnh m\u1ee9c nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,25 so v\u1edbi \u0111\u1ecbnh m\u1ee9c \u1ed1p \u0111\u00e1 v\u00e0o t\u01b0\u1eddng t\u01b0\u01a1ng \u1ee9ng<\/p>\n
33\/ C\u00f4ng t\u00e1c l\u00e1t n\u1ec1n, s\u00e0n: Khi l\u00e1t g\u1ea1ch granite nh\u00e2n t\u1ea1o th\u00ec hao ph\u00ed m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K= 1,3 so v\u1edbi \u0111\u1ecbnh m\u1ee9c t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
34\/ C\u00f4ng t\u00e1c l\u00e0m m\u1eb7t s\u00e0n g\u1ed7: N\u1ebfu v\u00e1n s\u00e0n \u0111\u00f3ng theo h\u00ecnh x\u01b0\u01a1ng c\u00e1, t\u1ea1o h\u00ecnh trang tr\u00ed theo thi\u1ebft k\u1ebf th\u00ec hao ph\u00ed nh\u00e2n c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n h\u1ec7 s\u1ed1 1,2.<\/p>\n
35\/ C\u00f4ng t\u00e1c s\u01a1n k\u1ebb \u0111\u01b0\u1eddng b\u1eb1ng s\u01a1n d\u1ebbo nhi\u1ec7t: N\u1ebfu chi\u1ec1u d\u00e0y l\u1edbp s\u01a1n kh\u00e1c v\u1edbi quy \u0111\u1ecbnh c\u1ee7a \u0111\u1ecbnh m\u1ee9c th\u00ec \u0111\u01b0\u1ee3c t\u00ednh n\u1ed9i suy t\u1eeb \u0111\u1ecbnh m\u1ee9c t\u01b0\u01a1ng \u1ee9ng.<\/p>\n
36\/ C\u00f4ng t\u00e1c phun, v\u1ea3y xi m\u0103ng gia c\u1ed1 v\u1ecf h\u00e1m: Khi ti\u1ebft di\u1ec7n h\u1ea7m =15m2 th\u00ec hao ph\u00ed nh\u00e2n c\u00f4ng, m\u00e1y thi c\u00f4ng \u0111\u01b0\u1ee3c nh\u00e2n v\u1edbi h\u1ec7 s\u1ed1 K=l,3.<\/p>\n
37\/ C\u00f4ng t\u00e1c khoan, phun v\u1eefa xi m\u0103ng gia c\u1ed1 v\u1ecf h\u00e1m: \u0110\u1ecbnh m\u1ee9c ch\u01b0a t\u00ednh l\u01b0\u1ee3ng ti\u00eau hao h\u1ed7n h\u1ee3p xi m\u0103ng khi phun<\/p>\n
38\/ C\u00f4ng t\u00e1c gi\u00e0n gi\u00e1o ph\u1ee5c v\u1ee5 thi c\u00f4ng: + Chi\u1ec1u cao \u0111\u1ec3 t\u00ednh kh\u1ed1i l\u01b0\u1ee3ng gi\u00e1o t\u00ednh t\u1eeb c\u1ea5t m\u1eb7t tr\u00ean n\u1ec1n thi c\u00f4ng \u0111\u1ebfn \u0111\u1ed9 cao l\u1edbn nh\u1ea5t \u0111\u1ea3m b\u1ea3o \u0111\u1ee7 thi c\u00f4ng k\u1ebft c\u1ea5u. + Gi\u00e0n gi\u00e1o ngo\u00e0i \u0111\u01b0\u1ee3c t\u00ednh theo di\u1ec7n t\u00edch m\u1eb7t c\u1eaft gi\u00e1o bao ngo\u00e0i c\u1ee7a k\u1ebft c\u1ea5u. + Gi\u00e0n gi\u00e1o trong ch\u1ec9 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng khi c\u00f4ng t\u00e1c c\u00f3 chi\u1ec1u cao thi c\u00f4ng >3.6m v\u00e0 \u0111\u01b0\u1ee3c t\u00ednh theo di\u1ec7n t\u00edch m\u1eb7t c\u1eaft gi\u00e1o b\u1ed1 tr\u00ed b\u00ean trong. Chi\u1ec1u cao gi\u00e0n gi\u00e1o t\u00ednh t\u1eeb m\u1eb7t s\u00e0n trong nh\u00e0 \u0111\u1ebfn chi\u1ec1u cao 3,6m, sau \u0111\u00f3 c\u1ee9 m\u00f4i kho\u1ea3ng chi\u1ec1u cao l,2m \u0111\u01b0\u1ee3c t\u00ednh th\u00eam 1 l\u1edbp gi\u00e1o ( kho\u1ea3ng t\u0103ng ch\u01b0a \u0111\u1ee7 0,6 m kh\u00f4ng \u0111\u01b0\u1ee3c t\u00ednh) + Th\u1eddi gian s\u1eed d\u1ee5ng gi\u00e0n gi\u00e1o trong \u0111\u1ecbnh m\u1ee9c t\u00ednh l\u00e0 = 1 th\u00e1ng. N\u1ebfu th\u1eddi gian s\u1eed d\u1ee5ng c\u1ee9 k\u00e9o d\u00e0i th\u00eam 1 th\u00e1ng th\u00ec t\u00ednh th\u00eam 1 l\u1ea7n hao ph\u00ed v\u1eadt li\u1ec7u. + Hao ph\u00ed v\u1eadt li\u1ec7u cho c\u00f4ng t\u00e1c b\u1ea3o v\u1ec7 an to\u00e0n (l\u01b0\u1edbi, v\u0103ng an to\u00e0 n v.v) v\u00e0 che ch\u1eafn b\u1ea3o v\u1ec7 m\u00f4i tr\u01b0\u1eddng \u0111\u01b0\u1ee3c t\u00ednh ri\u00eang.<\/p>","protected":false},"excerpt":{"rendered":"
Kinh nghi\u1ec7m khi b\u00f3c kh\u1ed1i l\u01b0\u1ee3ng d\u1ef1 to\u00e1n1. KINH NGHI\u1ec6M KHI B\u00d3C KH\u1ed0I L\u01af\u1ee2NG D\u1ef0 TO\u00c1N ( Ph\u1ea7n 1 ) ***1\/ B\u00f3c ph\u1ea7n b\u00ea t\u00f4ng kh\u00f4ng tr\u1eeb th\u00e9p hay d\u00e2y bu\u1ed9c chi\u1ebfm ch\u1ed7 \u0110i\u1ec1u n\u00e0y nhi\u1ec1u ng\u01b0\u1eddi bi\u1ebft nh\u01b0ng c\u0169ng c\u00f3 nh\u1eefng ng\u01b0\u1eddi kh\u00f4ng bi\u1ebft quy \u01b0\u1edbc \u1edf \u0111\u00e2u. Xin th\u01b0a \u0111\u01b0\u1ee3c quy \u0111\u1ecbnh t\u1ea1i […]\n","protected":false},"author":2,"featured_media":952,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[200,1],"tags":[],"_links":{"self":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts\/1161"}],"collection":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/comments?post=1161"}],"version-history":[{"count":2,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts\/1161\/revisions"}],"predecessor-version":[{"id":1163,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/posts\/1161\/revisions\/1163"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/media\/952"}],"wp:attachment":[{"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/media?parent=1161"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/categories?post=1161"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vxd.com.vn\/vi\/wp-json\/wp\/v2\/tags?post=1161"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}