Inappropriate design 39
by Natarajan (2007): ‘After all the exotic forensic theories and scenarios
had been exhausted, it turned out that the disaster was caused by an overlooked fact of simple high school level statics: That the substitution of two
rods in place of one in the particular fashion it was done doubled the load
at the nut’ (Figure 2.7).
2.3.5 thermal loading on thin marble façade
cladding, grande arche, Paris
One of the many remarkable buildings in Paris, France, is the 110 meters tall
Grande Arche, inaugurated in 1989. Less than 20 years after the inauguration, serious problems were noticed with the façade cladding. Large thermal
deformations were noticed, especially on the south side of the building, and
the marble claddings became more brittle. The effect of thermal loading
seemed to be clearly underestimated. Study revealed that during more than
150 days per year, the amplitude of the daily temperature variation on the
south façade surpassed 40°C. Due to this significant repeated thermal loading, thin marble façade claddings show expansion bowing, loss of strength,
and possibly detaching from the anchoring system (Grent et al. 2006).
2.4 InaPProPrIate estIMatIon
of creeP effects
When structures are loaded, structural deformations will occur. Normally,
these deformations are very small, and can hardly be noticed by the naked
eye. However, under sustained loading, deformations can increase in time.
This is the so-called creep effect, which is very important in concrete structures (Neville et al. 1983). The long-term deformation of concrete structures
under sustained loading can typically be two to five times higher than the
short-term deformation immediately after loading. Not duly considering
the effect of the increasing deformation with time can lead to unwanted
consequences.
In case of long-span bridges, the increased deflection due to creep effects
can clearly become visible, especially when looking in longitudinal direction. Creep effects can also be visible in other structures, as shown in
Figure 2.8. Although these creep deformations will not directly impair the
load bearing capacity of the structure, the excessive deformations are not
esthetic and might give an unsafe feeling.
In apartment or office buildings, creep effects might lead to cracking in
internal walls. These buildings are typically concrete skeleton buildings,
with a load bearing structure consisting of columns, beams, and slabs. The
internal walls are not bearing any load, and are typically made of a light
material like gypsum blocks. These light walls cannot follow excessive
by Natarajan (2007): ‘After all the exotic forensic theories and scenarios
had been exhausted, it turned out that the disaster was caused by an overlooked fact of simple high school level statics: That the substitution of two
rods in place of one in the particular fashion it was done doubled the load
at the nut’ (Figure 2.7).
2.3.5 thermal loading on thin marble façade
cladding, grande arche, Paris
One of the many remarkable buildings in Paris, France, is the 110 meters tall
Grande Arche, inaugurated in 1989. Less than 20 years after the inauguration, serious problems were noticed with the façade cladding. Large thermal
deformations were noticed, especially on the south side of the building, and
the marble claddings became more brittle. The effect of thermal loading
seemed to be clearly underestimated. Study revealed that during more than
150 days per year, the amplitude of the daily temperature variation on the
south façade surpassed 40°C. Due to this significant repeated thermal loading, thin marble façade claddings show expansion bowing, loss of strength,
and possibly detaching from the anchoring system (Grent et al. 2006).
2.4 InaPProPrIate estIMatIon
of creeP effects
When structures are loaded, structural deformations will occur. Normally,
these deformations are very small, and can hardly be noticed by the naked
eye. However, under sustained loading, deformations can increase in time.
This is the so-called creep effect, which is very important in concrete structures (Neville et al. 1983). The long-term deformation of concrete structures
under sustained loading can typically be two to five times higher than the
short-term deformation immediately after loading. Not duly considering
the effect of the increasing deformation with time can lead to unwanted
consequences.
In case of long-span bridges, the increased deflection due to creep effects
can clearly become visible, especially when looking in longitudinal direction. Creep effects can also be visible in other structures, as shown in
Figure 2.8. Although these creep deformations will not directly impair the
load bearing capacity of the structure, the excessive deformations are not
esthetic and might give an unsafe feeling.
In apartment or office buildings, creep effects might lead to cracking in
internal walls. These buildings are typically concrete skeleton buildings,
with a load bearing structure consisting of columns, beams, and slabs. The
internal walls are not bearing any load, and are typically made of a light
material like gypsum blocks. These light walls cannot follow excessive