Issue 73

Z. Xiong et alii, Fracture and Structural Integrity, 73 (2025) 267-284; DOI: 10.3221/IGF-ESIS.73.18

The maximum local stress f b of concrete under the limit state is assumed to be 0.85 f c in the above calculation, but the actual f b is related to the ratio of the width of the concrete abutment to the width of the steel girder ( w/b ). f b can be expressed as:

(20)

Mattock [23]

Tschemmernegg [24]

Hawkins [25]

Eurocode 2: -part 1–1

＜ 1.0

K

4.5 0.5

4.5 0.5

4.5 0.5

a c

1.0

0.66

0.55/0.60 w/b ≤4.5

0.50

0.33

w/b ≤12

f b ≤3.0 f c

Range

-

Table 5: Summarizes the coefficient values of f b calculated in the literature

In this paper, w/b=4 is selected based on the biased safety angle:

(21)

replacing 0.85 f c in Eq. (17) with Eq. (19), when β 1 varies between 0.65-0.85,2 β 1 - β 1 2 + 0.637is the mean value of 1.5645, and the maximum error is 3.3%.

(22)

C ONTRIBUTION FROM COMPOSITE DOWELS he bearing capacity of a single composite dowel is determined according to [11], namely:

T

(23)

The symbols are described as: η s reinforcement stirrup coefficient, 1 stirrups: η s = 0.9,2 stirrups: η s = 1 ,3stirrups: η s = 1.1; k size effect factor: k =1+(200/ c D,S ) 0.5 ;

f cm compressive strength of the concrete (MPa); c D,S compressive strength of the concrete (m); t steel thickness (m); e x center distance of the composite dowels (m); h d,eff effective steel tooth height (m). The bearing capacity of all composite dowels joints in the joint is assumed to be a polynomial relationship between Fs and F e : (24) C ONTRIBUTION FROM REINFORCEMENT RATIO n Fig. 25, the red part is the parameter sensitive region, and the blue part is the insensitive region. As mentioned above, the abutment reinforcement ratio ρ 1 increases from 0.7% to 1.3%, and the bearing capacity increases by about 3% with a change of 0.2 percentage points. The influence coefficient Z a of the abutment reinforcement ratio can be defined

I

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