{"id":8731,"date":"2009-03-24T04:18:24","date_gmt":"2009-03-23T21:18:24","guid":{"rendered":"http:\/\/vafs.gov.vn\/vn\/2009\/03\/su-truot-ngang-cua-lien-hop-may-khi-cay-ngam-tren-suon-doc\/"},"modified":"2019-09-24T11:05:09","modified_gmt":"2019-09-24T04:05:09","slug":"su-truot-ngang-cua-lien-hop-may-khi-cay-ngam-tren-suon-doc","status":"publish","type":"post","link":"https:\/\/vafs.gov.vn\/vn\/su-truot-ngang-cua-lien-hop-may-khi-cay-ngam-tren-suon-doc\/","title":{"rendered":"S\u1ef1 tr\u01b0\u1ee3t ngang c\u1ee7a Li\u00ean h\u1ee3p m\u00e1y khi c\u00e0y ng\u1ea7m tr\u00ean s\u01b0\u1eddn d\u1ed1c"},"content":{"rendered":"

S\u1ef1 tr\u01b0\u1ee3t ngang c\u1ee7a <\/strong><\/p>\n

Li\u00ean h\u1ee3p m\u00e1y khi c\u00e0y ng\u1ea7m tr\u00ean s\u01b0\u1eddn d\u1ed1c<\/strong><\/p>\n

Nguy\u1ec5n Can<\/em><\/strong><\/p>\n

Vi\u1ec7n Khoa h\u1ecdc L\u00e2m nghi\u1ec7p Vi\u1ec7t Nam<\/em><\/h4>\n

Di\u1ec7n t\u00edch \u0111\u1ea5t c\u1ea7n chu\u1ea9n b\u1ecb cho tr\u1ed3ng r\u1eebng c\u1ea3 n\u01b0\u1edbc hi\u1ec7n c\u00f3 h\u00e0ng ch\u1ee5c tri\u1ec7u hecta. Chu\u1ea9n b\u1ecb \u0111\u1ea5t tr\u1ed3ng r\u1eebng l\u00e0 kh\u00e2u ban \u0111\u1ea7u v\u00e0 chi\u1ebfm nhi\u1ec1u c\u00f4ng s\u1ee9c trong to\u00e0n b\u1ed9 qu\u00e1 tr\u00ecnh tr\u1ed3ng r\u1eebng;<\/p>\n

Nh\u1eefng k\u1ebft qu\u1ea3 nghi\u00ean c\u1ee9u nhi\u1ec1u n\u0103m t\u1ea1i Vi\u1ec7n KHLN cho th\u1ea5y chu\u1ea9n b\u1ecb \u0111\u1ea5t b\u1eb1ng c\u01a1 gi\u1edbi ho\u00e1 c\u00f3 nhi\u1ec1u \u01b0u \u0111i\u1ec3m h\u01a1n so v\u1edbi th\u1ee7 c\u00f4ng: n\u0103ng su\u1ea5t cao, t\u1ef7 l\u1ec7 c\u00e2y s\u1ed1ng v\u00e0 t\u1ed1c \u0111\u1ed9 t\u0103ng tr\u01b0\u1edfng sau khi tr\u1ed3ng cao \u2026 Tuy nhi\u00ean, cho \u0111\u1ebfn nay t\u1ef7 l\u1ec7 \u00e1p d\u1ee5ng c\u01a1 gi\u1edbi ho\u00e1 v\u00e0o chu\u1ea9n b\u1ecb \u0111\u1ea5t l\u00e2m nghi\u1ec7p c\u00f2n r\u1ea5t th\u1ea5p. M\u1ed9t trong nh\u1eefng nguy\u00ean nh\u00e2n l\u00e0 ph\u1ea7n l\u1edbn \u0111\u1ea5t l\u00e2m nghi\u1ec7p c\u00f3 \u0111\u1ed9 d\u1ed1c cao, trong khi li\u00ean h\u1ee3p m\u00e1y k\u00e9o v\u00e0 m\u00e1y l\u00e0m \u0111\u1ea5t (g\u1ecdi t\u1eaft l\u00e0 LHM) l\u00e0m vi\u1ec7c tr\u00ean \u0111\u1ea5t d\u1ed1c c\u00f3 kh\u1ea3 n\u0103ng \u1ed5n \u0111\u1ecbnh ngang th\u1ea5p.<\/p>\n

Kh\u1ea3 n\u0103ng \u1ed5n \u0111\u1ecbnh ngang c\u1ee7a LHM th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111\u00e1nh gi\u00e1 theo \u0111\u1ed9 tr\u01b0\u1ee3t c\u1ee7a x\u00edch tr\u00ean n\u1ec1n \u0111\u1ea5t theo ph\u01b0\u01a1ng d\u1ecdc v\u00e0 ngang v\u00e0 \u0111\u1ed9 d\u1ed1c t\u1ed1i thi\u1ec3u x\u1ea9y ra hi\u1ec7n t\u01b0\u1ee3ng l\u1eadt d\u1ecdc hay ngang c\u1ee7a LHM.<\/p>\n

Th\u1ef1c t\u1ebf cho th\u1ea5y kh\u1ea3 n\u0103ng l\u1eadt c\u1ee7a LHM th\u01b0\u1eddng ch\u1ec9 x\u1ea9y ra tr\u00ean nh\u1eefng \u0111\u1ed9 d\u1ed1c cao, trong khi hi\u1ec7n t\u01b0\u1ee3ng tr\u01b0\u1ee3t ngang c\u00f3 th\u1ec3 c\u1ea3m nh\u1eadn \u0111\u01b0\u1ee3c ngay tr\u00ean nh\u1eefng \u0111\u1ed9 d\u1ed1c ch\u1ec9 5 \u0111\u1ed9 \u0111\u1ebfn 7 \u0111\u1ed9. Hi\u1ec7n t\u01b0\u1ee3ng tr\u01b0\u1ee3t ngang l\u00e0m t\u0103ng ti\u00eau hao c\u00f4ng su\u1ea5t v\u00f4 \u00edch, gi\u1ea3m t\u00ednh n\u0103ng kinh t\u1ebf k\u1ef9 thu\u1eadt c\u1ee7a vi\u1ec7c s\u1eed d\u1ee5ng m\u00e1y m\u00f3c, l\u00e0m t\u0103ng gi\u00e1 th\u00e0nh s\u1ea3n xu\u1ea5t.<\/p>\n

\u0110\u1ec3 t\u00ecm bi\u1ec7n ph\u00e1p h\u1ea1n ch\u1ebf s\u1ef1 tr\u01b0\u1ee3t ngang, nh\u1eb1m m\u1ee5c ti\u00eau n\u00e2ng cao kh\u1ea3 n\u0103ng c\u01a1 gi\u1edbi ho\u00e1 chu\u1ea9n b\u1ecb \u0111\u1ea5t tr\u00ean s\u01b0\u1eddn d\u1ed1c, trong th\u1eddi gian qua ch\u00fang t\u00f4i \u0111\u00e3 ti\u1ebfn h\u00e0nh nghi\u00ean c\u1ee9u hi\u1ec7n t\u01b0\u1ee3ng tr\u01b0\u1ee3t ngang c\u1ee7a LHM khi l\u00e0m \u0111\u1ea5t tr\u00ean s\u01b0\u1eddn d\u1ed1c. \u0110\u1ec1 t\u00e0i \u0111\u01b0\u1ee3c nghi\u00ean c\u1ee9u theo ph\u01b0\u01a1ng ph\u00e1p l\u00fd thuy\u1ebft k\u1ebft h\u1ee3p v\u1edbi th\u1ef1c nghi\u1ec7m ki\u1ec3m ch\u1ee9ng tr\u00ean m\u00f4 h\u00ecnh \u0111\u1ed3ng d\u1ea1ng v\u00e0 th\u1ef1c nghi\u1ec7m tr\u00ean li\u00ean h\u1ee3p m\u00e1y th\u1ef1c t\u1ea1i \u0111\u1ea5t r\u1eebng thu\u1ed9c Trung t\u00e2m Khoa h\u1ecdc v\u00e0 S\u1ea3n xu\u1ea5t L\u00e2m nghi\u1ec7p \u0110\u00f4ng B\u1eafc b\u1ed9.<\/p>\n

1. N\u1ed9i dung nghi\u00ean c\u1ee9u tr\u01b0\u1ee3t ngang c\u1ee7a LHM<\/h2>\n

S\u1ef1 tr\u01b0\u1ee3t ngang c\u1ee7a LHM l\u00e0 s\u1ef1 tr\u01b0\u1ee3t c\u1ee7a x\u00edch v\u1edbi n\u1ec1n, ph\u1ee5 thu\u1ed9c v\u00e0o kh\u1ea3 n\u0103ng b\u00e1m c\u1ee7a x\u00edch tr\u00ean n\u1ec1n v\u00e0 s\u1ef1 c\u1ee9ng v\u1eefng c\u1ee7a l\u1edbp \u0111\u1ea5t d\u01b0\u1edbi m\u1eb7t t\u1ef1a x\u00edch. C\u00f3 th\u1ec3 chia s\u1ef1 tr\u01b0\u1ee3t ngang ra ba tr\u01b0\u1eddng h\u1ee3p nh\u01b0 sau:<\/p>\n

– Tru\u1ee3t m\u1eb7t ngo\u00e0i, do l\u1ef1c b\u00e1m x\u00edch v\u00e0 m\u1eb7t n\u1ec1n kh\u00f4ng \u0111\u1ee7 l\u1edbn; s\u1ef1 tr\u01b0\u1ee3t m\u1eb7t ngo\u00e0i c\u00f3 th\u1ec3 x\u1ea9y ra theo ph\u01b0\u01a1ng ngang v\u1edbi c\u00e1c lo\u1ea1i x\u00edch th\u00f4ng th\u01b0\u1eddng ch\u1ec9 c\u00f3 m\u1ea5u c\u1ea3n theo chi\u1ec1u d\u1ecdc. LHM kh\u00f4ng th\u1ec3 l\u00e0m vi\u1ec7c \u0111\u01b0\u1ee3c n\u1ebfu b\u1ecb tr\u01b0\u1ee3t tr\u01a1n m\u1eb7t ngo\u00e0i<\/p>\n

– Tr\u01b0\u1ee3t do bi\u1ebfn d\u1ea1ng c\u1ee7a l\u1edbp \u0111\u1ea5t b\u1ec1 m\u1eb7t khi ch\u1ecbu l\u1ef1c, moment t\u1eeb x\u00edch truy\u1ec1n \u0111\u1ebfn, l\u00e0 d\u1ea1ng ch\u1ee7 y\u1ebfu v\u00e0 th\u01b0\u1eddng x\u1ea9y ra.<\/p>\n

– Tr\u01b0\u1ee3t tr\u00ean l\u1edbp \u0111\u1ea5t t\u01a1i v\u1ee5n ho\u1eb7c ph\u1ee7 l\u1edbp v\u1eadt li\u1ec7u r\u1eddi, c\u00e1c ph\u1ea7n t\u1eed \u0111\u00f3 tr\u01b0\u1ee3t v\u1edbi nhau t\u1ea1o n\u00ean s\u1ef1 tr\u01b0\u1ee3t c\u1ee7a LHM v\u1edbi v\u1eadn t\u1ed1c l\u1edbn. \u0110\u00e2y l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng th\u01b0\u1eddng x\u1ea3y tr\u00ean nh\u1eefng s\u01b0\u1eddn \u0111\u1ed3i x\u00f3i m\u00f2n l\u00e2u n\u0103m tr\u01a1 s\u1ecfi \u0111\u00e1, ho\u1eb7c x\u1ea9y ra c\u1ee5c b\u1ed9 tr\u00ean nh\u1eefng \u0111\u00e1m \u0111\u1ea5t b\u1ecb x\u1edbi n\u00e1t ho\u1eb7c ph\u1ee7 x\u00e1c c\u00e2y c\u1ecf b\u1ecf l\u1ea1i t\u1eeb c\u00f4ng \u0111o\u1ea1n d\u1ecdn th\u1ef1c b\u00ec.<\/p>\n

B\u00e0i b\u00e1o n\u00e0y tr\u00ecnh b\u00e0y hi\u1ec7n t\u01b0\u1ee3ng tr\u01b0\u1ee3t do bi\u1ebfn d\u1ea1ng c\u1ee7a l\u1edbp \u0111\u1ea5t d\u01b0\u1edbi m\u1eb7t ti\u1ebfp x\u00fac v\u1edbi x\u00edch, c\u00f2n \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 “s\u1ef1 tr\u01b0\u1ee3t tr\u00ean n\u1ec1n \u0111\u1ea5t \u0111\u00e0n h\u1ed3i”.<\/p>\n

a\/ C\u01a1 s\u1edf nghi\u00ean c\u1ee9u s\u1ef1 tr\u01b0\u1ee3t ngang do bi\u1ebfn d\u1ea1ng c\u1ee7a \u0111\u1ea5t<\/em><\/strong><\/p>\n

Khi chuy\u1ec3n \u0111\u1ed9ng tr\u00ean s\u01b0\u1eddn d\u1ed1c, LHM ch\u1ecbu t\u00e1c \u0111\u1ed9ng c\u1ee7a c\u00e1c l\u1ef1c v\u00e0 moment ngang, trong \u0111\u00f3 ph\u00e2n l\u1ef1c tr\u1ecdng l\u01b0\u1ee3ng b\u1ea3n th\u00e2n c\u1ee7a LHM theo h\u01b0\u1edbng xu\u1ed1ng d\u1ed1c (G.sinb) l\u00e0 nguy\u00ean nh\u00e2n ban \u0111\u1ea7u. Do x\u00edch b\u00e1m ch\u1eb7t v\u00e0o \u0111\u1ea5t n\u00ean c\u00e1c l\u1ef1c v\u00e0 moment n\u00f3i tr\u00ean truy\u1ec1n t\u1eeb x\u00edch m\u00e1y k\u00e9o v\u00e0o \u0111\u1ea5t, g\u00e2y ra bi\u1ebfn d\u1ea1ng c\u1ee7a \u0111\u1ea5t d\u01b0\u1edbi v\u1ebft ti\u1ebfp x\u00fac, d\u1eabn \u0111\u1ebfn s\u1ef1 chuy\u1ec3n d\u1ecbch c\u1ee7a LHM, c\u00f3 ngh\u0129a l\u00e0 gi\u00e1 tr\u1ecb chuy\u1ec3n d\u1ecbch c\u1ee7a x\u00edch, t\u1ee9c l\u00e0 c\u1ee7a LHM, \u0111\u00fang b\u1eb1ng gi\u00e1 tr\u1ecb bi\u1ebfn d\u1ea1ng c\u1ee7a \u0111\u1ea5t t\u1ea1i v\u1ebft ti\u1ebfp x\u00fac.<\/p>\n

S\u1ef1 bi\u1ebfn d\u1ea1ng c\u1ee7a \u0111\u1ea5t l\u00e0m ph\u00e1t sinh \u1ee9ng su\u1ea5t ti\u1ebfp trong \u0111\u1ea5t c\u1ea3n l\u1ea1i bi\u1ebfn d\u1ea1ng. Theo nghi\u00ean c\u1ee9u c\u1ee7a ti\u1ebfn s\u0129 M.G. Bekker; \u1ee9ng su\u1ea5t c\u1ea3n tv\u00e0 bi\u1ebfn d\u1ea1ng y quan h\u1ec7 theo c\u00f4ng th\u1ee9c:<\/p>\n

(1)<\/p>\n

Trong \u0111\u00f3 ymax l\u00e0 bi\u1ebfn d\u1ea1ng c\u1ef1c \u0111\u1ea1i c\u1ee7a \u0111\u1ea5t, m;<\/p>\n

tmax<\/sub>: \u1ee9ng su\u1ea5t ti\u1ebfp c\u1ef1c \u0111\u1ea1i c\u1ee7a \u0111\u1ea5t khi b\u1ecb bi\u1ebfn d\u1ea1ng, N\/m2<\/sup>;<\/p>\n

C\u00f4ng th\u1ee9c (1) ph\u1ee9c t\u1ea1p do t\u00ednh phi tuy\u1ebfn c\u1ee7a n\u00f3, c\u00f3 th\u1ec3 \u0111\u01a1n gi\u1ea3n b\u1eb1ng c\u00e1ch s\u1eed d\u1ee5ng \u0111o\u1ea1n tuy\u1ebfn t\u00ednh c\u1ee7a qu\u00e1 tr\u00ecnh bi\u1ebfn d\u1ea1ng v\u1edbi c\u00f4ng th\u1ee9c:<\/p>\n

(2)<\/p>\n

Tr\u1ecb s\u1ed1 kt<\/sub>(kN\/m3<\/sup>) l\u00e0 h\u1ec7 s\u1ed1 \u0111\u1eb7c tr\u01b0ng gi\u00e1 tr\u1ecb \u1ee9ng su\u1ea5t (kN\/m2<\/sup>) sinh ra khi \u0111\u1ea5t b\u1ecb bi\u1ebfn d\u1ea1ng (m), x\u00e1c \u0111\u1ecbnh b\u1eb1ng th\u1ef1c nghi\u1ec7m.<\/p>\n

b\/ \u0110\u1ed9 l\u1edbn c\u1ee7a tr\u01b0\u1ee3t ngang do bi\u1ebfn d\u1ea1ng c\u1ee7a \u0111\u1ea5t<\/em><\/strong><\/p>\n

S\u1ef1 chuy\u1ec3n d\u1ecbch c\u1ee7a LHM tr\u00ean n\u1ec1n l\u00e0 do c\u00e1c l\u1ef1c v\u00e0 moment b\u00ean ngo\u00e0i g\u00e2y n\u00ean, bao g\u1ed3m:<\/p>\n

– Ph\u00e2n l\u1ef1c tr\u1ecdng l\u01b0\u1ee3ng G c\u1ee7a li\u00ean h\u1ee3p m\u00e1y tr\u00ean n\u1ec1n c\u00f3 \u0111\u1ed9 d\u1ed1c b;<\/p>\n

– C\u00e1c ph\u1ea3n l\u1ef1c c\u1ee7a \u0111\u1ea5t t\u00e1c \u0111\u1ed9ng theo ph\u01b0\u01a1ng n\u1eb1m ngang th\u00e2n c\u00e0y PCY;<\/p>\n

– Moment l\u1ef1c c\u1ea3n l\u0103n v\u00e0 c\u00e1c moment do c\u00e1c ngo\u1ea1i l\u1ef1c n\u00f3i tr\u00ean t\u1ea1o n\u00ean;<\/p>\n

T\u1ed5ng l\u1ef1c g\u00e2y chuy\u1ec3n d\u1ecbch tr\u01b0\u1ee3t ngang l\u00e0 t\u1ed5ng l\u1ef1c theo ph\u01b0\u01a1ng O1<\/sub>Y1<\/sub>:<\/p>\n

SPY = G.sinb.cosj- PCY (3)<\/p>\n

v\u00e0 t\u1ed5ng moment quay SMZ t\u00ednh v\u1edbi t\u00e2m \u00e1p l\u1ef1c K l\u00e0:<\/p>\n

SMZ = Mcl + (a +e).G.sinb. cosj – (lC \u2013e).PCY (4)<\/p>\n

Trong \u0111\u00f3 Mcll\u00e0 moment sinh ra do ch\u00eanh l\u1ec7ch l\u1ef1c c\u1ea3n l\u0103n t\u1ea1i hai gi\u1ea3i x\u00edch ;<\/p>\n

a : kho\u1ea3ng c\u00e1ch tr\u1ecdng t\u00e2m m\u00e1y k\u00e9o O \u0111\u1ebfn \u0111i\u1ec3m gi\u1eefa x\u00edch I (xem h\u00ecnh 1);<\/p>\n

e : \u0111\u1ed9 l\u1ec7ch t\u00e2m \u00e1p l\u01b0c K, so v\u1edbi \u0111i\u1ec3m gi\u1eefa m\u1eb7t t\u1ef1a x\u00edch I (xem h\u00ecnh 1);<\/p>\n

D\u01b0\u1edbi t\u00e1c d\u1ee5ng c\u1ee7a c\u00e1c l\u1ef1c v\u00e0 moment ngo\u1ea1i l\u1ef1c n\u00f3i tr\u00ean, LHM b\u1ecb chuy\u1ec3n dich ngang (Y1<\/sub>) v\u00e0 chuy\u1ec3n dich g\u00f3c (j). S\u1eed d\u1ee5ng c\u00e1c t\u00ednh to\u00e1n v\u00e0 l\u00fd thuy\u1ebft c\u01a1 h\u1ecdc , c\u00f3 th\u1ec3 x\u00e1c \u0111\u1ecbnh \u0111\u01b0\u1ee3c v\u1eadn t\u1ed1c c\u00e1c chuy\u1ec3n d\u1ecbch \u0111\u00f3 theo c\u00f4ng th\u1ee9c:<\/p>\n

(5)<\/p>\n

(6)<\/p>\n

v\u1edbi c\u00e1c h\u1eb1ng s\u1ed1: (7)<\/p>\n

(8)<\/p>\n

Trong \u0111\u00f3 Vthl\u00e0 v\u1eadn t\u1ed1c chuy\u1ec3n \u0111\u1ed9ng d\u1ecdc tr\u1ee5c m\u00e1y k\u00e9o, c\u00f3 t\u00ednh \u0111\u1ebfn tr\u01b0\u1ee3t d\u1ecdc c\u1ee7a x\u00edch;<\/p>\n

bx, lx, Cx: b\u1ec1 r\u1ed9ng, chi\u1ec1u d\u00e0i t\u01b0a v\u00e0 kho\u1ea3ng c\u00e1c t\u00e2m c\u1ee7a hai gi\u1ea3i x\u00edch.<\/p>\n

C\u00f4ng th\u1ee9c (5) v\u00e0 (6) cho th\u1ea5y:<\/p>\n

– \u0110\u1ed9 l\u1edbn chuy\u1ec3n d\u1ecbch ngang Y1<\/sub> t\u0103ng khi t\u0103ng t\u1ed5ng l\u1ef1c ngang SPY, chuy\u1ec3n d\u1ecbch g\u00f3c j t\u0103ng khi t\u0103ng t\u1ed5ng moment SMZ;<\/p>\n

– Chuy\u1ec3n d\u1ecbch Y1<\/sub> v\u00e0 j t\u0103ng khi \u0111\u1eb7c tr\u01b0ng \u1ee9ng su\u1ea5t kt<\/sub> c\u1ee7a \u0111\u1ea5t gi\u1ea3m;<\/p>\n

– Chuy\u1ec3n d\u1ecbch Y1<\/sub> v\u00e0 jgi\u1ea3m khi chi\u1ec1u d\u00e0i t\u1ef1a lX, b\u1ec1 r\u1ed9ng bX v\u00e0 kho\u1ea3ng t\u00e2m CX c\u1ee7a x\u00edch t\u0103ng.<\/p>\n

H\u00ecnh 1. S\u01a1 \u0111\u1ed3 m\u1eb7t b\u1eb1ng c\u00e1c l\u1ef1c v\u00e0 moment c\u1ee7a li\u00ean h\u1ee3p m\u00e1y khi c\u00e0y tr\u00ean s\u01b0\u1eddn d\u1ed1c<\/em><\/p>\n

T\u00edch ph\u00e2n hai ph\u01b0\u01a1ng tr\u00ecnh (5) v\u00e0 (6) theo th\u1eddi gian t s\u1ebd \u0111\u01b0\u1ee3c t\u1ed5ng chuy\u1ec3n d\u1ecbch ngang (Y1<\/sub>) v\u00e0 xoay (j) c\u1ee7a LHM sau th\u1eddi gian t n\u00e0o \u0111\u00f3. Do chuy\u1ec3n d\u1ecbch ngang v\u00e0 xoay g\u00f3c, chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a LHM s\u1ebd b\u1ecb l\u1ec7ch v\u1edbi h\u01b0\u1edbng \u0111i ban \u0111\u1ea7u Y, \u0111\u01b0\u1ee3c x\u00e1c \u0111\u1ecbnh theo h\u1ec7 ph\u01b0\u01a1ng tr\u00ecnh:<\/p>\n

(9)<\/p>\n

(10)<\/p>\n

c\/ K\u1ebft qu\u1ea3 nghi\u00ean c\u1ee9u tr\u01b0\u1ee3t ngang do bi\u1ebfn d\u1ea1ng c\u1ee7a \u0111\u1ea5t<\/em><\/strong><\/p>\n

X\u00e9t b\u00e0i to\u00e1n tr\u00ean LHM Komatsu D65A-8, l\u1eafp 2 th\u00e2n c\u00e0y l\u00e0m vi\u1ec7c tr\u00ean v\u00f9ng \u0111\u1ed3i mi\u1ec1n B\u1eafc, khi kh\u00f4ng t\u00e1c \u0111\u1ed9ng v\u00e0o h\u1ec7 th\u1ed1ng l\u00e1i: H\u00ecnh 2 tr\u00ecnh b\u00e0y qu\u1ef9 \u0111\u1ea1o LHM l\u00e0m vi\u1ec7c ngang s\u01b0\u1eddn d\u1ed1c 15o<\/sup>, 2 th\u00e2n c\u00e0y s\u00e2u 0,55m, qu\u1ef9 \u0111\u1ea1o c\u1ee7a LHM l\u00e0 m\u1ed9t \u0111\u01b0\u1eddng cong h\u01b0\u1edbng xu\u1ed1ng ch\u00e2n d\u1ed1c. \u0110\u1ed3 th\u1ecb cho th\u1ea5y sau 100 gi\u00e2ykh\u1edfi h\u00e0nh, LHM b\u1ecb xoay g\u00f3c 15,63o<\/sup> v\u00e0 \u0111\u1ed9 l\u1ec7ch t\u1ed5ng c\u1ed9ng theo ph\u01b0\u01a1ng ngang l\u00e0 12,28m.<\/p>\n

H\u00ecnh 2. Qu\u1ef9 \u0111\u1ea1o chuy\u1ec3n \u0111\u1ed9ng c\u1ee7a D65A-8 l\u1eafp 2 th\u00e2n c\u00e0y s\u00e2u 0,55m, trong 100s \u0111\u1ea7u ti\u00ean. <\/em><\/p>\n

X\u00e9t theo \u0111\u1ed9 d\u1ed1c, k\u1ebft qu\u1ea3 cho th\u1ea5y khi \u0111\u1ed9 d\u1ed1c t\u0103ng, gi\u00e1 tr\u1ecb chuy\u1ec3n d\u1ecbch xoay (j) v\u00e0 chuy\u1ec3n d\u1ecbch xu\u1ed1ng d\u1ed1c (Y) \u0111\u1ec1u t\u0103ng; \u0111\u00f3 l\u00e0 do x\u00ea d\u1ecbch ngang v\u00e0 d\u1ecbch chuy\u1ec3n xoay \u0111\u1ec1u ph\u1ee5 thu\u1ed9c r\u1ea5t nhi\u1ec1u v\u00e0o \u0111\u1ed9 d\u1ed1c. \u0110\u1ed9 d\u1ed1c l\u00e0 nguy\u00ean nh\u00e2n ch\u00ednh g\u00e2y ra s\u1ef1 tr\u01b0\u1ee3t ngang c\u1ee7a LHM tr\u00ean s\u01b0\u1eddn d\u1ed1c.<\/p>\n

X\u00e9t \u1ea3nh h\u01b0\u1edfng c\u1ee7a chi\u1ec1u s\u00e2u c\u00e0y t\u1edbi gi\u00e1 tr\u1ecb tr\u01b0\u1ee3t ngang ta th\u1ea5y khi chi\u1ec1u s\u00e2u hC t\u0103ng, d\u1eabn \u0111\u1ebfn \u0111\u1ed9 l\u1ec7ch t\u00e2m e t\u0103ng, moment xoay MZt\u0103ng, l\u00e0m g\u00f3c l\u1ec7ch h\u01b0\u1edbng jt\u0103ng, k\u1ebft qu\u1ea3 d\u1ecbch chuy\u1ec3n ngang (Y) t\u0103ng.<\/p>\n

2. K\u1ebft lu\u1eadn<\/u><\/h3>\n

Tr\u01b0\u1ee3t ngang l\u00e0 hi\u1ec7n t\u01b0\u1ee3ng lu\u00f4n x\u1ea9y ra \u0111\u1ed1i v\u1edbi LHM l\u00e0m \u0111\u1ea5t tr\u00ean s\u01b0\u1eddn d\u1ed1c, g\u00e2y kh\u00f3 kh\u0103n cho vi\u1ec7c \u00e1p d\u1ee5ng c\u01a1 gi\u1edbi ho\u00e1 v\u00e0o c\u00f4ng vi\u1ec7c chu\u1ea9n b\u1ecb \u0111\u1ea5t canh t\u00e1c n\u00f4ng l\u00e2m nghi\u1ec7p. Bi\u1ec7n ph\u00e1p h\u1ea1n ch\u1ebf s\u1ef1 tr\u01b0\u1ee3t ngang c\u1ee7a LHM khi l\u00e0m \u0111\u1ea5t tr\u00ean s\u01b0\u1eddn d\u1ed1c l\u00e0:<\/p>\n

– \u0110\u1ec3 tr\u00e1nh tr\u01b0\u1ee3t m\u1eb7t ngo\u00e0i, kh\u00f4ng n\u00ean \u0111\u1ec3 m\u00e1y l\u00e0m vi\u1ec7c tr\u00ean \u0111\u1ed9 d\u1ed1c qu\u00e1 cao ho\u1eb7c khi n\u1ec1n \u0111\u1ea5t tr\u01a1n \u01b0\u1edbt;<\/p>\n

– \u0110\u1ec3 tr\u00e1nh tr\u01b0\u1ee3t tr\u00ean l\u1edbp v\u1eadt li\u1ec7u r\u1eddi, c\u1ea7n tr\u00e1nh cho x\u00edch \u0111i tr\u00ean v\u1ebft x\u00edch tr\u01b0\u1edbc ho\u1eb7c tr\u00ean \u0111\u1ea5t \u0111\u00e3 c\u00e0y, h\u1ea1n ch\u1ebf l\u00e0m t\u01a1i v\u1ee5n \u0111\u1ea5t tr\u01b0\u1edbc khi c\u00e0y; c\u00e1c bi\u1ec7n ph\u00e1p n\u00e0y nh\u1eb1m \u0111\u1ea3m b\u1ea3o \u0111\u1ed9 b\u00e1m c\u1ee7a x\u00edch khi l\u00e0m vi\u1ec7c;<\/p>\n

– \u0110\u1ec3 h\u1ea1n ch\u1ebf s\u1ef1 tr\u01b0\u1ee3t do bi\u1ebfn d\u1ea1ng, c\u1ea7n tr\u00e1nh l\u00e0m \u0111\u1ea5t khi \u0111\u1ea5t b\u1ec1 m\u1eb7t qu\u00e1 m\u1ec1m; \u0111\u1ed3ng th\u1eddi c\u1ea7n l\u1ef1a ch\u1ecdn m\u00e1y k\u00e9o c\u00f3 di\u1ec7n t\u00edch m\u1eb7t t\u1ef1a x\u00edch (bx, Cx, lx) l\u1edbn, kho\u1ea3ng c\u00e1ch tr\u1ee5 c\u00e0y \u0111\u1ebfn t\u00e2m m\u1eb7t t\u1ef1a x\u00edch (lx) nh\u1ecf.<\/u><\/h3>\n

Vi\u1ec7c h\u1ea1n ch\u1ebf s\u1ef1 tr\u01b0\u1ee3t ngang s\u1ebd gi\u00fap n\u00e2ng cao kh\u1ea3 n\u0103ng s\u1eed d\u1ee5ng m\u00e1y m\u00f3c thi\u1ebft b\u1ecb trong chu\u1ea9n b\u1ecb \u0111\u1ea5t canh t\u00e1c n\u00f4ng l\u00e2m nghi\u1ec7p tr\u00ean s\u01b0\u1eddn d\u1ed1c, g\u00f3p ph\u1ea7n \u0111\u1ea9y nhanh t\u1ed1c \u0111\u1ed9 ph\u1ee7 xanh \u0111\u1ea5t tr\u1ed1ng \u0111\u1ed3i n\u00fai tr\u1ecdc.<\/p>\n

T\u00e0i li\u1ec7u tham kh\u1ea3o<\/strong><\/p>\n

1. Nguy\u1ec5n H\u1eefu C\u1ea9n, Pham Minh Th\u00e1i, Nguy\u1ec5n V\u0103n T\u00e0i, D\u01b0 Qu\u1ed1c Th\u1ecbnh (1978), L\u00fd thuy\u1ebft \u00f4 t\u00f4 m\u00e1y k\u00e9o<\/em>, gi\u00e1o tr\u00ecnh \u0110\u1ea1i h\u1ecdc B\u00e1ch khoa H\u00e0 N\u1ed9i, Nh\u00e0 xu\u1ea5t b\u1ea3n \u0110H v\u00e0 THCN, H\u00e0 N\u1ed9i.<\/p>\n

2. Manfred Steene (1979), Ph\u00e2n t\u00edch t\u1ed5ng h\u1ee3p v\u00e0 t\u00ednh to\u00e1n \u0111\u01b0\u1eddng cong l\u1ef1c ch\u1ee7 \u0111\u1ed9ng – \u0110\u1ed9 tr\u01b0\u1ee3t c\u1ee7a b\u00e1nh m\u00e1y k\u00e9o tr\u00ean \u0111\u1ea5t bi\u1ebfn d\u1ea1ng<\/em>. Lu\u1eadn \u00e1n ti\u1ebfn s\u0129, C\u1ed9ng ho\u00e0 d\u00e2n ch\u1ee7 \u0110\u1ee9c.<\/p>\n

Summary<\/strong><\/p>\n

Horizontal slide is an occurrence when bulldozer are moving horizontally on the slope; bulldozer is normally turned horizontally and redirected as a result of soil layers beneath the chain contacted tracks, sometimes slide of chain against the ground occurs as a result of weak cling to its ground or the soil surface turned up. The occurrence exerts harmful influence on the technical parameters of bulldozer. In order to reduce the occurrence, it is necessary to apply proper soil making processes and to select proper tractors and soil cultivation machines.<\/p>\n","protected":false},"excerpt":{"rendered":"

S\u1ef1 tr\u01b0\u1ee3t ngang c\u1ee7a Liên h\u1ee3p máy khi cày ng\u1ea7m trên s\u01b0\u1eddn d\u1ed1c Di\u1ec7n tích \u0111\u1ea5t c\u1ea7n chu\u1ea9n b\u1ecb cho tr\u1ed3ng r\u1eebng c\u1ea3 n\u01b0\u1edbc hi\u1ec7n có hàng ch\u1ee5c tri\u1ec7u hecta. Chu\u1ea9n b\u1ecb \u0111\u1ea5t tr\u1ed3ng r\u1eebng là khâu ban \u0111\u1ea7u và chi\u1ebfm nhi\u1ec1u công s\u1ee9c trong toàn b\u1ed9 quá trình tr\u1ed3ng r\u1eebng; Nh\u1eefng k\u1ebft qu\u1ea3 nghiên c\u1ee9u nhi\u1ec1u n\u0103m t\u1ea1i Vi\u1ec7n KHLN cho th\u1ea5y chu\u1ea9n b\u1ecb \u0111\u1ea5t b\u1eb1ng c\u01a1 gi\u1edbi hoá có nhi\u1ec1u \u01b0u \u0111i\u1ec3m h\u01a1n so v\u1edbi th\u1ee7 công: n\u0103ng su\u1ea5t cao, t\u1ef7 l\u1ec7 cây s\u1ed1ng và t\u1ed1c \u0111\u1ed9 t\u0103ng tr\u01b0\u1edfng sau khi tr\u1ed3ng cao … Tuy nhiên, cho \u0111\u1ebfn nay t\u1ef7 l\u1ec7 áp d\u1ee5ng c\u01a1 gi\u1edbi hoá vào chu\u1ea9n b\u1ecb \u0111\u1ea5t lâm nghi\u1ec7p còn r\u1ea5t th\u1ea5p. M\u1ed9t trong nh\u1eefng nguyên nhân là ph\u1ea7n l\u1edbn \u0111\u1ea5t lâm nghi\u1ec7p có \u0111\u1ed9 d\u1ed1c cao, trong khi liên h\u1ee3p máy kéo và máy làm \u0111\u1ea5t (g\u1ecdi t\u1eaft là LHM) làm vi\u1ec7c trên \u0111\u1ea5t d\u1ed1c có kh\u1ea3 n\u0103ng \u1ed5n \u0111\u1ecbnh ngang th\u1ea5p. Kh\u1ea3 n\u0103ng \u1ed5n \u0111\u1ecbnh ngang c\u1ee7a LHM th\u01b0\u1eddng \u0111\u01b0\u1ee3c \u0111ánh giá theo \u0111\u1ed9 tr\u01b0\u1ee3t c\u1ee7a xích trên n\u1ec1n \u0111\u1ea5t theo ph\u01b0\u01a1ng d\u1ecdc và ngang và \u0111\u1ed9 d\u1ed1c t\u1ed1i thi\u1ec3u x\u1ea9y ra hi\u1ec7n t\u01b0\u1ee3ng l\u1eadt d\u1ecdc hay ngang c\u1ee7a LHM. <\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[18],"tags":[],"_links":{"self":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/8731"}],"collection":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/comments?post=8731"}],"version-history":[{"count":2,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/8731\/revisions"}],"predecessor-version":[{"id":19100,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/posts\/8731\/revisions\/19100"}],"wp:attachment":[{"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/media?parent=8731"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/categories?post=8731"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vafs.gov.vn\/vn\/wp-json\/wp\/v2\/tags?post=8731"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}