Failure Due to Compression or Crushing

Q. At the base of a gravity dam section, the vertical stress at toe was found to be 3.6 MPa. If the downstream face of dam has slope of 0.707 H : 1 V and if there is no tail water, then the maximum principal stress at the toe of the dam is

1. 3 MPa
2. 4.5 MPa
3. 3.5 MPa
4. 5.4 MPa

Q. Maximum vertical compressive stress acting at the base of a gravity dam is found to be 240 tonnes per square meter. Sum of vertical and horizontal forces acting on the dam are calculated as 4600 tonnes and 400 tonnes per meter length respectively. If the base width of the dam is 30 m, the resultant force will be acting with an eccentricity of ____

1. 1.8 m
2. 2.8 m
3. 4.3 m
4. 5.1 m

Q. Following data were obtained from the stability analysis of a concrete gravity dam:
Weight of the dam = 6500 tonnes/m
Uplift force = 1500 tonnes/m
Base width of dam = 60 m
The resultant force acts at 25 m from the toe.
The maximum vertical stress on the foundation soil will be

1. $291.67t/m^2$
2. $125t/m^2$
3. $41.67t/m^2$
4. $162.5t/m^2$