BAO CAO BTNC

8/7/2019 BAO CAO BTNC

1/17

TIU LUN BTCTNC GVHD: TS.H HU CHNH

THC HNH TNH TON TI TRNG NG T TC NGLN CNG TRNH

1. Gii thiu

Ti cc nc pht trin, vic xy dng cng trnh c kh nng chu ti trng ng t lyu cu bt buc nhm bo m sinh mng cho con ngi v gim thiu tn tht kinh t dohu qu ng t. Vit Nam, sau khi b xy dng ban hnh TCXDVN 375:2006 Tiuchun thit k cng trnh chu ng t, c th ni vic thit k khng chn cho cng trnhl mt trong nhng bt buc v chun mc trong cng tc thit k hin nay.Bi bo co ny trnh by cc cch tnh ti trng ng t theo cc quy phm Vit Nam,

v cc iu cn quan tm trong vic thit k cng trnh hin nay.

2. Ni dung bo coBi bo co ny gm nhng ni dung chnh sau: Khi qut cc phng php tnh ti trng

ng t. Cch tnh ng t theo TCXDVN 375:2006 thng qua cc v d tnh ton cth. V trong bi bo co cng trnh by cch ng dng chng trnh my tnh Etabs h trcho vic tnh ton khng chn.

HVTH: NGUYN THANH TN-02108494


2/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHA. Khi qut phng php tnh ton ti trng ng tTnh ton ti trng ng t c th c chia thnh 2 nhm: Phng php phn tch n

hi tuyn tnh v phng php phi tuyn.1. Phng php n hi tuyn tnh (Linear analysis). Nhng h qu ca tc ng ng

t v nhng h qu ca cc tc ng khc k n trong thit k chu ng t c thxc nh trn c s ng x n hi tuyn tnh ca kt cu.

Ty thuc vo c trng kt cu nh, c th s dng mt trong hai phng php phn tchn hi tuyn tnh sau:- Phng php phn tch tnh lc ngang tng ng: Ch p dng cho nh tha

mn cc iu kin nht nh v cu to.- Phng php phn tch ph phn ng dng dao ng: C th p dng cho mi loi

nh.2. Phng php phi tuyn (Nonliner analysis).Dn dn c chp nhn trong cng ng thit k chuyn nghip nh l mt phng

php c th pht trin nh gi s lm vic ca cng trnh hin hu.Hai loi phn tch phi tuyn l:

- Phn tch phi tuyn tnh NSP (Nonlinear Static Procedure, Pushover Procedure)- Phn tch phi tuyn ng NDP (Nonlinear Dynamic Procedure)

C hai phng php phn tch phi tuyn ny i hi s chun b cc m hnh ton phituyn ca khung nh. Nh vy cc v tr c th ng x phi tuyn (thng gi l khp do)trong khung phi c xc nh trong m hnh ton. Cc quan h phi tuyn lc bin dng

phi c lp trc cho tng thnh phn khung nh c kh nng ng x phi tuyn.

Trong phm vi bo co ny, ch trnh by cch tnh ton thc hnh theo nhm phngphp n hi tuyn tnh v so snh gia cc phng php .



3/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHB. Thc hnh tnh ton ti trng ng t tc dng ln cng trnh

Sau y trnh by hai cch phn tch tnh lc ngang tng ng v ph phn ng dngdao ng cho cng mt bi ton. T a ra cc nhn xt v kt qu tnh.

1. Bi tonXt bi ton ny c m hnh kt cu tha cc iu kin phn tch bng phng phptnh lc ngang tng ng.

- Cc chu k dao ng c bn T1 theo hai hai hng nh hn cc gi tr sau:

s

TT

C

0,2

.41

- Tha mn nhng tiu ch v tnh u n theo mt ng.



4/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHa. Phng php tnh lc ngang tng ngCc bng sau l kt qu tnh phn tch chu k dao ng, khi lng v chuyn v tng

Bng 1. Cc chu k dao ng c bnChu k dao ng

c bn (s)T1x T1y

1.11 1.509

Bng 2. Khi lng v chuyn v tng theo dao dao ng c bn.

Gi s c s liu tnh ng t cho cng trnh nh sau.

1

LOAI ATNEN S TB(s) Tc(s) Td(s)

C 1.15 0.20 0.60 2.00Gia toc nentham chieu (g) agR = 0.0848 1= 1.25

hs: qh = 1.50


Story displacements

T1x T1y

Story mj(Kg) Story sj sj1 379081 1 -0.0004 0.00062 477552 2 -0.0012 0.00163 477552 3 -0.0021 0.00294 477552 4 -0.0033 0.00455 477552 5 -0.0046 0.0061

6 477552 6 -0.0061 0.00777 477552 7 -0.0077 0.00948 477552 8 -0.0094 0.01099 477552 9 -0.0111 0.012410 477552 10 -0.0128 0.013811 477552 11 -0.0146 0.015112 477552 12 -0.0163 0.016213 477552 13 -0.0181 0.017214 477552 14 -0.0198 0.018115 477552 15 -0.0214 0.0189

M = 7064809


5/17


T xy dng ph phn ng dng dao ng thit k cho cng trnh nh sau:

Phophan ng an hoi theo phng ngang

0.25

0.5

0.75

1

1.25

1.5

1.75

2

2.25

T

Se

Tnh lc ct y mng thit k theo cng thc sau:

= M),T(SF 1db (1)

trong :Sd (T1, ) Tung ca ph thit k ti chu k T1;T1 Chu k dao ng c bn do chuyn ng ngang theo phng ang xt; H s hiu chnh, ly nh sau: = 0,85 nu T1 2TC vi nh > 2 tng; = 1,0 vi cctrng hp khc.M Tng khi lng nh trn mng tnh lc ct y mngFb, xc nh

bng:

+=1i

i,ki,E

1j

j,k QGM (2)



6/17


Gk,j - tnh ti tnh ton th j ; Qk,i - hot ti tnh ton th i; E,i-h s t hp ti trng i vi tc ng thay i th i;

Hot ti t ln nh 2 E = x 2Loi A: Khu vc nh , gia nh 0,3 0,8 0,24

Loi B: Khu vc vn phng 0,3 0,8 0,24

Loi C: Khu vc hi hp 0,6 0,8 0,48

Loi D: Khu vc mua bn 0,6 1,0 0,6

Loi E: Khu vc kho lu tr 0,8 1,0 0,8

Theo phng XT chu k dao ng c bn theo phng X: T1x = 1.109, tnh c 0783.1),( 1 =Xd TSLc ct y mng:

)(7617983170648090783.1 NFbX

==

Phn phi lc ct y cho cc tng theo cng thc sau:

b

jj

kkk F

ms

msF =

(3)Trong :

Fk lc ngang tc dng ti tng th k

Fb lc ct y do ng t tnh theo (1)

sk, sj chuyn v ca cc khi lng mk , mj trong dng dao ng c bn.mk, mj khi lng ca cc tng.

T cng thc (2)v s liu trongbng 2, tnh clc ngang phnphi ln tng nhsau:

Bng 3. Phnphi ti ngangtheo phng Xln tng tng.


FbX = 7617.983 KN

Story mj(Kg) sj mjsj FkX (KN)

1 379081 -0.0004 -151.632 16.32 477552 -0.0012 -573.062 61.43 477552 -0.0021 -1002.86 107.54 477552 -0.0033 -1575.92 168.95 477552 -0.0046 -2196.74 235.56 477552 -0.0061 -2913.07 312.37 477552 -0.0077 -3677.15 394.28 477552 -0.0094 -4488.99 481.29 477552 -0.0111 -5300.83 568.210 477552 -0.0128 -6112.67 655.211 477552 -0.0146 -6972.26 747.412 477552 -0.0163 -7784.1 834.413 477552 -0.0181 -8643.69 926.514 477552 -0.0198 -9455.53 1013.615 477552 -0.0214 -10219.6 1095.5

M = 7064809 -71068.1


7/17


TNH LC NGANG TNG NG THEO PHNG X

1

2

3

4

5

6

7

89

10

11

12

13

14

15

KN

TNG

Theo phng YT chu k dao ng c bn theo phng Y: T1Y = 1.509, tnh c 7925.0),( 1 =Yd TSLc ct y mng:

)(5598861170648097925.0 NFbY

==



8/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHBng 4. Phn phi ti ngang theo phng Y ln tng tng.

TNH LC NGANG TNG NG THEO PHNG

1

23

4

5

6

7

8

9

10

11

12

13

14

15

KN

TNG

b. Phng php phn tch ph dng dao ngTheo phng php ny, phi xt n tt c dng dao ng gp phn ng k vo phn ngtng th ca nh, trong tnh ton thc hnh, c th s dng cc iu kin sau:


FbY = 5598.861 KN

Story mj(Kg) sj mjsj FkY (KN)

1 379081 0.0006 227.4487 17.22 477552 0.0016 764.0831 57.73 477552 0.0029 1384.901 104.64 477552 0.0045 2148.984 162.35 477552 0.0061 2913.067 220.06 477552 0.0077 3677.15 277.67 477552 0.0094 4488.988 338.98 477552 0.0109 5205.316 393.09 477552 0.0124 5921.644 447.110 477552 0.0138 6590.217 497.611 477552 0.0151 7211.035 544.512 477552 0.0162 7736.342 584.113 477552 0.0172 8213.894 620.214 477552 0.0181 8643.69 652.615 477552 0.0189 9025.732 681.5

M = 7064809 74152.49


9/17


s2,0T

n3k

k

(4)

trong :ks dng dao ng c xt ti trong tnh ton;

n s tng trn mng hoc nh ca phn cng pha di;

Tkchu k dao ng ca dng th k(chu k dao ng b nht c xt n tnhton)

Nh 15 tng 6.11153 =k , chn 12=k . Phn tch vi 12 dng dao ng u tin.

Bng 5. Chu k dao ngMode 1 2 3 4 5 6 7 8 9 10 11 12

Period 1.510 1.297 1.110 0.436 0.375 0.248 0.212 0.189 0.126 0.121 0.110 0.088

C th thy dng dao ng th 12 c chu k 0.008s < 0.2s.

Bng 6. Ti trng ngang theo phng X ln tng tngFbX = 5903.8 KN

Stoty FkX 15 944.16



10/17

TIU LUN BTCTNC GVHD: TS.H HU CHNH14 842.98 13 660.52 12 508.29 11 399.34 10 335.48 9 307.39

8 300.57 7 301.92 6 301.91 5 292.56 4 266.2 3 217.8 2 149.63 1 75.09

TI NGANG TNG NG PHNG X

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

KN

TNG

Bng 7. Ti trng ngang theo phng Y ln tng tngFbY = 4599.1 KN



11/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHStoty

15 763.83 14 655.9 13 498.41 12 385.02 11 313.52

10 268.28 9 239.8 8 226.68 7 224.4 6 224.15 5 220.7 4 210.43 3 182.94 2 127.96 1 57.08

TI NGANG TNG NG PHNG Y

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

KN

TNG

c. So snh kt qu t 2 phng php



12/17


TI NGANG THEO PHNG X

012

3456789

101112

131415

KN

TNG

TNH T

PH DAO

TI NGANG THEO PHNG Y

0123

456789

10111213

1415

KN

TNG

TNH T

PH DAO

2. Mt s nhn xt



13/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHT kt qu phn tch trn c th cho cng trnh trn, c mt s nhn xt nh sau:- C s sai khc v kt qu tnh theo 2 phng php trn.

Bng 8. So snh lc ct y

i lng Sai s(KN) TLNT PD (%)

FbX 7618.0 5903.8 22.5

FbY 5598.9 4599.1 17.9

Phng php

- Quy lut phn phi ti ngang ln tng tng theo hai phng php l rt khc nhau, theophng php phn tch tnh lc ngang tng ng, ti ngang phn b ln tng tng cdng tng gn tuyn tnh, cn theo phng php phn tch ph dao ng th khng.



14/17

TIU LUN BTCTNC GVHD: TS.H HU CHNHTI LIU THAM KHO

1. H Hu Chnh. Bi ging mn kt cu b-tng nng cao, chng trnh cao hcXDDDCN. HBK TP. H Ch Minh

2. TCXDVN 375 -2006. Thit k cng trnh chu ng t.



15/17




16/17




17/17


PH LCCc s liu v chu k dao ng, khi lng cng trnh, chuyn v tng ng vi cc

do dao ng, lc ct tng trong tnh ton trn ly t kt qu xut ra ca chngtrnh Etabs.


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