Parent document

Concrete Bridge Assessment

Preformatted Tables

Table 1: Predicted versus actual ultimate loads for Cambridge model bridge slabs

                   Hudson tests                Kite tests       
                                                          
 Test No.        H1    H2    H3    H4     K1    K2    K3    K4  
 Ptest (kN)     29.2  28.3  27.9  19.0   23.4  23.5  24.1  22.7 
 PCOBRAS (kN)   24.5  25.3  23.0  17.2   22.5  22.3  20.5  17.7 
 Ptest/PCOBRAS  1.19  1.12  1.21  1.10   1.04  1.05  1.18  1.28   

                  Collins tests               Antill tests
                   
 Test No.        C1    C2    C3                 A1    A2
 Ptest (kN)     36.8  37.2  31.3               18.0  25.6
 PCOBRAS (kN)   N/A   28.5  25.7               19.0  29.3 
 Ptest/PCOBRAS   -    1.33  1.22               0.95  0.87

Table 2: Revised load capacities of bridges re-assessed using COBRAS by the author

                            
 Bridge  Span   Elastic  Plastic Rating
   No.    (m)    Rating     COBRAS
                (tonne)     (tonne)

    1    4.85     7.5         38
    2    6.50     7.5         16
    3    3.89    38           40
    4    5.70    16           16
    5    6.55     7.5         16
    6    5.70    17           40
    7    3.66     7.5         40
    8    3.72    38           40
    9    5.51     7.5         40
   10    3.71     7.5         38
   11    6.60     7.5         40
   12    6.60     7.5         40
   13    6.50     3           40
   14   13.10     7.5         40
   15    6.10     7.5         40
   16    5.40     7.5         40
   17    2.48    17           40
   18    3.29    17           40
   19    7.62    38           40
   20    3.00     7.5         16
   21    3.06     7.5         40

Table 3: Revised load capacities of bridges re-assessed by County Council's using COBRAS

                              Elastic        Plastic
 Bridge Span  Skew angle  Assessment Live   Assessment
  No.    (m)  (degrees)     Load Rating     Live Load
                              (tonne)     Rating (tonne)

 Bedfordshire County Council
   1     3.6      5            25                40
   2     5.5      3             7.5              40
   3     6.8      7             7.5*             40*
   4     4.9      25           17*               40*

 Northumberland County Council
   1     5.0      0      Group 1 FE              40*
   2     5.0      0      Group 1 FE              38*
   3    4.65     10.5    Group 1 FE              40*
   4    3.51      0             38               40*
   5    2.95     43.6           25               40*
   6    10.7      0      Dead load only          40*

 Cumbria County Council
   1    7.33     31.5            7.5             40
   2    3.81      0              7.5             40
   3    7.71     14.5           25               40
                             
   4    18.5     54.2    Dead plus superimposed  40
                         dead load only

* provisional results since not checked as yet.