204 Ground improvement by deep vibratory methods
In a recent study, Achmus et al. (2007) have investigated the impact of
various depth vibrators on adjacent buildings by evaluating PPV measurements. In total, over 200 vibration measurements on over 20 different construction sites using four different Keller depth vibrators were analyzed.
Vibrator data were according to Table 3.1 and a typical ground PPV (PPV G )
relationship versus distance from the vibrator is given in Figure 6.2 for
the M- and S-vibrators, which are characterized by the nominal vibratory
energy E according to Equation 6.3 and PPV G from Equation 6.4. The
factor K in Equation 6.4 is an empirical correlation factor developed from
a multitude of vibration measurements of different ground engineering
methods and can be found in Vrettos (2009).
E
W
f
=
in kNm
(6.3)
where:
f is the vibrator frequency in Hz
W is the nominal vibrator power in kW
Table 6.1 Design values for the maximum horizontal PPV at the top floor level of a
building due to steady-state vibration (according to DIN 4150-3)
Building type
Design values for the horizontal PPV of construction
elements at the top floor level, DPPV h (mm/s)
Industrial buildings
10
Residential buildings
5
Very sensitive buildings
2.5
Source: From Achmus, M. et al., Untersuchung zu Bauwerks—und Bodenerschütterungen infolge
Tiefenrüttlung, in 3. Hans Lorenz Symposium, Grundbauinstitut H. 41, TU Berlin, 2007.
Table 6.2 Design values for the maximum resultant PPV for construction elements of
buildings (according to SN 640312a)
Sensitivity classes
Frequency class
Design values for the resultant PPV of
construction elements, DPPV res (mm/s)
Normal sensitivity
(e.g., usual residential
buildings, office
buildings)
Occasional
Frequent
Permanent
f < 30 Hz
15
6
3
f = 30–60 Hz
20
8
4
f > 60 Hz
30
12
6
Little sensitivity (e.g.,
industrial buildings)
Up to two times the respective values
for normally sensitive buildings
Increased sensitivity
(e.g., new residential
and historic buildings)
Between 100% and 50% of the
respective values for normally sensitive
buildings
Source: From Achmus, M. et al., Untersuchung zu Bauwerks—und Bodenerschütterungen infolge
Tiefenrüttlung, in 3. Hans Lorenz Symposium, Grundbauinstitut H. 41, TU Berlin, 2007.
In a recent study, Achmus et al. (2007) have investigated the impact of
various depth vibrators on adjacent buildings by evaluating PPV measurements. In total, over 200 vibration measurements on over 20 different construction sites using four different Keller depth vibrators were analyzed.
Vibrator data were according to Table 3.1 and a typical ground PPV (PPV G )
relationship versus distance from the vibrator is given in Figure 6.2 for
the M- and S-vibrators, which are characterized by the nominal vibratory
energy E according to Equation 6.3 and PPV G from Equation 6.4. The
factor K in Equation 6.4 is an empirical correlation factor developed from
a multitude of vibration measurements of different ground engineering
methods and can be found in Vrettos (2009).
E
W
f
=
in kNm
(6.3)
where:
f is the vibrator frequency in Hz
W is the nominal vibrator power in kW
Table 6.1 Design values for the maximum horizontal PPV at the top floor level of a
building due to steady-state vibration (according to DIN 4150-3)
Building type
Design values for the horizontal PPV of construction
elements at the top floor level, DPPV h (mm/s)
Industrial buildings
10
Residential buildings
5
Very sensitive buildings
2.5
Source: From Achmus, M. et al., Untersuchung zu Bauwerks—und Bodenerschütterungen infolge
Tiefenrüttlung, in 3. Hans Lorenz Symposium, Grundbauinstitut H. 41, TU Berlin, 2007.
Table 6.2 Design values for the maximum resultant PPV for construction elements of
buildings (according to SN 640312a)
Sensitivity classes
Frequency class
Design values for the resultant PPV of
construction elements, DPPV res (mm/s)
Normal sensitivity
(e.g., usual residential
buildings, office
buildings)
Occasional
Frequent
Permanent
f < 30 Hz
15
6
3
f = 30–60 Hz
20
8
4
f > 60 Hz
30
12
6
Little sensitivity (e.g.,
industrial buildings)
Up to two times the respective values
for normally sensitive buildings
Increased sensitivity
(e.g., new residential
and historic buildings)
Between 100% and 50% of the
respective values for normally sensitive
buildings
Source: From Achmus, M. et al., Untersuchung zu Bauwerks—und Bodenerschütterungen infolge
Tiefenrüttlung, in 3. Hans Lorenz Symposium, Grundbauinstitut H. 41, TU Berlin, 2007.