Phân tích kết cấu bộ phận công tác của thiết bị khoan phun trộn cọc xi măng đất

Mdt trong nhflng phfldng phdp xfl ly nln columns, soil mixing pile, la mdt cpc hinh tru yeu hilu qua Id dung cpc xi mdng dat khdng cd cdt trdn tao thdnh bdi hdn h ^ dflpc trdn diu gifla

Phan tich ket cau bo phan cong tdc caa thiQt bj khoan - phan - tron coc xi mang ddt

PGS.TS Nguyin H6ng Ngdn', ThS Huynh Cdng Ldn", ThS Trdn Cdng TriS

'Bd mdn Cd gidi hda Xi nghiep Xdy dflng, Khoa Cd khi, Trfldng Dai hpc Bdeh khoa TR HCM

^Bd mdn May Xay dflng, Khoa Cd khi, Trfldng Dai hpc Giao thdng Vdn tdi TP HCM

TOM TAT

Bdi viet trinh bdy scf lUdc vi gidi phdp xii ly nin ddt yiu bdng cgc xi mdng ddt Phdn tich dnh hudng cua kit cdu bg phdn ldm viic din chdt lUdng cgc xi mdng ddt Tii do dUa ra kit cdu ldm viec phii hdp vdi diiu kien tU nhiin cua Viet Nam, dong thdi, dUa ra cdc thong so ky thudt cua cong nghi cgcxi mdng ddt dp dung trong nhiing diiu kien ddt khdc nhau

Nhilu cdng trinh xdy dflng cua nfldc ta 2.1 Gidi thieu chung

dfldc thflc hiln trln nln dat ylu Di xdy dflng can

phdi tiln hdnh xfl ly nln mdng sao cho hilu qua Cpc xi mang dat (hay cdn gpi Id cpt xi

va tilt kilm, phu hpp dilu kiln kinh t l - ky thudt mang dat, tru xi mdng dat) - (Deep soil mixing

cu thi Mdt trong nhflng phfldng phdp xfl ly nln columns, soil mixing pile), la mdt cpc hinh tru yeu hilu qua Id dung cpc xi mdng dat khdng cd cdt trdn tao thdnh bdi hdn h ^ dflpc trdn diu gifla thep dat nguyin trang vdi xi mang dfldc phun xuong

nln dat bdi thilt bi khoan - phun

Cdng nghe thi cdng tao cpc xi mdng dat

dflpc dp dung d nfldc ta chfla Idu, nhilu van dl Qud trinh thi cdng tao thdnh cpc xi mang

vl ly ludn vd thflc tiln van cdn chfla dflpc nghiln dat dung phfldng phdp khoan trdn sdu Sfl dung cflu day du, dac bilt la nhflng nghiln cflu vl kit mdy khoan vd cdc thilt bi chuyin dflng (can cau cua bd phdn lam viec - mdt trong nhflng ylu khoan, mui khoan ), khoan vdo dat vdi dfldng

td anh hfldng ldn nhat din chat Iflg'ng cua cpc xi kinh vd chilu sdu Id khoan theo thilt kl Dat mang ddt trong qud trinh khoan khdng dfldc lay lln khoi lo

khoan ma bi phd vd kit cau, dfldc cdc canh mui Vdi nhflng xu t h i dd, viec nghien cflu gidi khoan nghiln tdi, trdn diu vdi chat kit dinh (chat quylt van d l vl kit cdu cua bd phdn lam viec d l kit dinh thdng thfldng Id xi mang hoac vdi, thach phu hdp vdi dilu kiln tfl nhien cua nfldc ta la hit cao ddi khi cd thlm chat phu gia va cat),

sflc can thilt

TAP CHf CO KHf VlfiT NAM • Sd 03 (Thang 3 nam 2012)

Qua trinh phun (hoac bdm), chat kit dinh

dl trdn vdi dat trong hd khoan, tuy theo ylu cau

cd thi dfldc thflc hiln d cd hai pha khoan xudng

vd rut lln cua mui khoan hoac chi thflc hiln d pha

rut mui khoan lln De trdnh ldng phi xi mdng, han

chi xi mang thodt ra khdi mat dat, gdy d nhiem

mdi trfldng, thdng thfldng, khi rut mui khoan lln

each dp cao mat dat tfl 0,5 1,5m ngfldi ta dflng

phun chat kit dinh, nhflng doan cpc 0,5 1,5m ndy

van dfldc phun day du chat kit dinh Id nhd chat

kit dinh cd trong dfldng dng tilp tuc dflpc phun

(hodc bdm) vdo hd khoan

Khi mui khoan dflpc rut lln khdi hd

khoan, trong hd khoan cdn lai dat da dflpc trpn

deu vdi chat kit dinh dan dan ddng cflng, tao

thanh cpc xi mang dat

Hiln cd cdng nghe trdn khd (Dry Jet

Mix-ing) vd cdng nghe trdn fldt (Wet Mixing hay cdn

gpi la Jet - Grouting):

- Trdn khd Id qud trinh phun trdn xi mang khd

vdi ddt cd hoac khdng cd chat phu gia

- Trdn fldt Id qud trinh bdm trdn vfla xi mang vdi

dat cd hoac khdng cd chat phu gia

#111^

A

Hinh 2.2: Cac bUdc thi cdng trpn kho

Thi cdng cdi tao nln dat ylu bang cpc xi mang dat theo phfldng phdp trdn khd theo cdc bfldc sau:

- Dinh vi vd dfla thilt bi thi cdng vdo vi tri thilt kl;

- Khoan ha dau phun trdn xudng day khdi dat can gia cd;

- Bat dau qua trinh khoan trdn vd keo dan dau khoan lln din mieng Id;

- Ddng tat thilt bi thi cdng va chuyen sang vi tri mdi

l U M V A t r ^

TAP CHf CO KHf VlfiT NAM V Sd 03 (Thang 3 nam 2012)

cr^

2.3 Ung dung

Hinh 2.4; Cac buOc llii cong Iron not

2.2 Uu vd nhfldc dilm

Uu dilm ndi bdc cua cpc xi mdng ddt:

- Thi cdng nhanh, ky thudt thi cdng khdng phflc

tap, ylu td rui ro thdp

- Tilt Idem thdi gian thi cdng din hdn 50% do

khdng phdi chd due cpc vd dat du cfldng dp

- Hilu qud kinh t l cao, gid thdnh ha hdn nhilu so

vdi phfldng dn khdc

- Rat thich hpp cho cdng tdc xfl ly nln mdng cho

cac cdng trinh d cdc khu vflc nln ddt ylu nhfl bdi

bdi, ven sdng, ven biln

- Cd thi thi cdng dflpc trong nhflng dilu ki|n

mat bang chat hep, ngdp nfldc

- Khd nang xfl ly khd sdu (cd thi din 50m)

Nhflpc dilm:

- Kha nang chdng xd ngang kim (do khdng cd cdt

thep) neu chi dflng ddn le

- Chat Iflpng cac cpc khac nhau khd ddng diu (do

tinh chat dat nln vd qua trinh cap xi mang khdng

ddng nhat)

- Qua trinh nghiln cflu vl cpc xi mang dat cdn

chfla hoan thien

Mpt sd td hpp thilt bi dflpc trang bi h? thdng dilu khiln hi|n dai, todn bd cdc thao tdc thi cdng cpc gia cd dflpc tfl ddng hda theo cdc chfldng trinh, cdc sd li|u vl Iflpng xi mdng sfl dung tren tflng mit cpc dflpc hiln thi, lflu gifl vd in thanh bdng kit qua thi cdng cho tflng cpc

Khi xdy dflng cdc cdng trinh cd tdi trpng ldn trln nln dat ylu, cdn phdi cd cdc biln phdp xfl ly dat nln bin dfldi mdng cdng trinh, nhat la nhflng khu vflc cd tang ddt ylu ddy cd hilu qua cao, dflpc dp dung cho cdc cdng trinh xdy dflng giao thdng, thuy lpi, sdn bay, bin cang,

Nd cd thi sfl dung de lam tfldng hdo chdng tham cho d l dap, gia cd dat xung quanh dfldng ham, dn dinh tfldng chdn, chdng trflpt dat cho mdi ddc, gia cd nln dfldng, md cau dan

So vdi mdt sd gidi phdp xfl ly nln hiln

CO, cdng ngh| cpc xi mdng dat cd flu dilm Id kha

nang xfl ly sdu, thich hprp vdi cdc loai dat ylu (tfl cat thd cho din bim ylu), thi cdng dfldc cd trong dilu kiln nln ngdp sdu trong nfldc hoac dilu kiln hiln trfldng chat hep, trong nhilu trfldng hpp, da dem lai sfl tilt kilm ddng k l so vdi cdc giai phap xfl ly khdc (nlu sfl dung phfldng phap cpc bl tdng

ep hoac cpc khoan nhdi thi rat tdn kem do tdng ddt ylu ben trln day)

L A M VlfiC DEN CHAT LU'ONG COC XI MANG DAT

TAP CHf CO KHf VIET NAM ••• S6 03 (Thane 3 nam 2012)

Quy trinh lam chat dat nen:

a) b) c)

Hinh 3.1 Quy trinh ldm chat nen

a) Khoan cat pha dat nen, d6ng thdi bom viia

b) Cat nhuyen dat va trpn that deu vdi viia

c) Tao mot h6n h<?p deu v^ dong nhat

Trong vile dp dung cdng nghe thi cdng cpc

xi mdng dat, viec trdn lan sao cho cd dat va vfla

xi mang hda that diu nhau ddng mpt vai trd rat

quan trpng vi phan flng xuc tdc gifla hai nguyin

to ndy se quylt dinh dp cflng cua tru cpc Do dd,

may khoan dfldc thilt k l vdi mdt loai lfldi khoan

rat dac bilt vd dflpc gpi la "lfldi khoan teno" Nlu

khdng sfl diing loai cdng cu ddc bilt ndy, khi trdn

nln ddt set, dat se bi ddng thdnh cue vd bi cudn

xoay theo lfldi khoan cua mdy khoan Hdn nfla,

nd se hi ddng thdnh tflng khdi dat ldn hinh tru vd

dflpc bpc bin ngodi bdi ldp vfla mdng

Vile sfl dung lfldi khoan quay vd tinh giflp

cat dat ra thdnh nhflng phan rat nhuyen, de tao

dieu kiln cho vfla xi mang trdn diu vdo dat thanh

mpt hdn hpp ddng nhat

,1

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1

Hinh 3.2: Dat bi cuon theo lUdi khoan thfldng

Thilt bi khoan - trdn:

a) ^ b)

Hinh 3.3: Thiet bi khoan - tron

a) Lxidi Idioan d trang thai tinh

b) Liidi Idioan d trang thai quay

f

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y

Lil9i khoan Teno

, - - • " 1 X'-'^

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HiMng li^c cua dS't & dinh ouay

3.4: H LI ong luc cua dat va canh

kWra CO

Oat - vja

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a) b)

Hinh 3.5: Mat cat tilt dien coc a) Khong dung "liiSi khoan teno"

b) Ddng "liiQi khoan teno"

Mat cat cpc da hodn thi|n;

a) b)

Hinh 3.6: Mdt cdt cpc da hodn thi|n

a) Khong diing "lUdi khoan teno"

b) DCing "lildi khoan teno"

Cdc dang bp cdng tdc khoan - trpn phd

biln hiln nay:

•^

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Hinh 3.7: Bp khoan - trpn cua Dflc

Hinh 3.9: Bd khoan - trdn cua Nhdt

Hinh 3.10: Bd khoan - trpn cua Tnmg Quoc

Tfl nhflng cd sd trln, ta dfla ra dflpc kit cau bd cdng tdc dp diing cho dilu kiln tfl nhiln cua Vilt Nam

Hinh 3.8: Bd khoan - trdn cua My

Hinh 3.11: Kit cau dau khoan - trdn

Thdng sd ddu khoan - trdn xi mang:

Dudng kinh tru: 1000 mm Chilu dai ddu khoan: 1200 mm Dfldng kinh dau khoan: 120 mm

TAP CHf CO KHf VlfiT NAM • S6 03 (Thdng 3 nam 2012)

- Yi tri Id phun hdn hpp xi mang dfldi dau mui

khoan

Dac tinh ky thudt trdn:

- Van tdc xuyIn xudng: 0,7 H- l(m/ph)

- Van tdc rut lln: 1 - 2(m/ph)

- Tdc dp quay cua cdnh trpn: 24 -H 64 (vg/ph)

- Khdi Iflpng vfla phun: 70 -;- 300 (kg/m')

4 THONG SO KY T H U A T CUA C O N G NGHfi

KIEN DAT K H A C NHAU:

5 KET L U A N

Tfl nhflng phdn tich trln cho thay phfldng phap cpc xi mang dat hodn todn cd thi thay thi cac phfldng phdp khdc (cpc cdt, cpc bac thdm, ) trong cdng tdc xfl ly nln dat ylu d Viet Nam

Kit cau bp phdn ldm vile cua thilt bi la ylu td dnh hfldng ldn nhat den chat Iflpng cpc xi mang ddt Dfla vao nhflng phdn tich trln, ta hodn todn cd thi dfla ra kit cau hpp ly nhat phu hpp vdi dilu kiln cua nfldc ta

K L CCIIKOI

1> If oark

L Up; Iii cia T e n Cokinu

Tl W HcMoMc

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- Doi vdi cat pha set:

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- Doi vdi dat hflu cd:

BAT Hfjl CO

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III i i i -in Iras) (.u

TI.-O

TAP CHI CO KHI VI

Kii'n nghi:

Trong giai doan hiln nay neu tiep tuc hodn thiln ly thuylt kit hpp vdi thflc nghilm thi

di tai trln cd the dp dung vdo cho nhilu cdng

trinh xdy dflng vdi dieu kiln tfl nhiln khac nhau

d l cd thi phdn anh chinh xdc hdn ve ban chat cua nln dat

Hfldng phat trien cua de tai: nghiln cflu cdc yeu td khdc dnh hfldng tdi chat Iflpng cpc

xi mang dat, tfl dd hodn thiln hdn nfla cho chat Iflpng cdng trinh khi sfl dung cdng nghe nay

Tai lieu tham khao:

[1] Le Quy An, Nguyen Cong Man, Nguyen Wn Quy, Co hoc dat, NXB Giao due, 1995

[2] Chau NgQC An, Ca hpc dit, NXB Dai hoc Qu6c gia TP.HCM, 2004 [3] Bergado D.T, Chai J.C, Alfaro M.C, Nhflng bien phap ky thuat m6i cai tao dat yeu trong xay diJng NXB Giao due, 1996

[4] NguySn Quoc Dung, Phung Vinh An, Nguyin Qu6c Huy, Cong nghe khoan phyt cao ip trong xii ly nen dat yeu, NXB Nong nghifp, 2005 [5] Nguyin Diic Hanh, Pham Thanh H4

Mpt s6 CP ch^ phd hoai ciia nln dSp tren dat yeu diing cpc dSt gia co xi mang Tap chi Cau Dfldng Vi|t Nam, s6 5/2007

[6] Bp X4y dflng Tap chi Xay dflng Viet Nam, 385, 2006 Gia co nen dat

ylu b4ng try dat xi m&ng, Hi Npi 2006

[7], Trln Xudn Tiiy, Dflong Kim Ai M6 hinh thflc nghilm may khoan phun cpc xi mang dat tfl dpng, Dai hpc Bdeh khoa D4 Nang, 2000

[8] Bahner, Eric W.,Naguib, Aiman M Ground Improvement for Large Above Ground Petroleum Storage Tanks Using Deep Mixing, GEODEN-VER 2000, Denver CO in press 2000

[9] Kenneth B.Andromalos, Yasser A.Hegazy, Brian H.Jasperse, Stabili-zation of soft soils by soil mixing, Monroevllle, PA, USA

[10] United States Patent - Yoshio Ichise; Akio Yamakado, both of Tokyo; Shoji Takano, Yokohama, all of Japan Hight Pressure Jet-Grouting Method Appl.No:195,196-Nov.3,1971

[11] Nagih M.El-Rawi; Ali A.A.Al-Wash Strength and thermal properties

of plain and reinforced soil-cement Journal of Islamic Academy of Sciences 8:3, 107-108, 1995

So 03 (Thang 3 nam 2012)