Abstract:
Padma Multipurpose Bridge is situated on a section of the Padma river where
the soil condition is highly heterogeneous and intermixed with different soil
layers, for which pile design was the critical part. This paper describes the soil
properties and ground profiling of the Padma Multipurpose Bridge. Different
types of field and laboratory tests were carried out to obtain accurate soil
parameters and ground profiles along the whole alignment of the bridge.
Standard Penetration Tests, Cone Penetration Tests, and grain size analyses
were conducted for the soil classifications and ground profiling. Flat Plate
Dilatometer Tests, High Pressure Dilatometer Tests, and Self-Boring Internal
Friction Tests were performed to obtain the stiffness of the different soil layers
and shear strength parameters in field conditions. Cross-hole and Seismic
Tomography Geophysical tests were executed to obtain seismic waves and
dynamic shear modulus of each soil layer. Gel Push Soil Sampling technique was
used to collect undisturbed samples of sandy soils to get accurate stress–
strength-dilatancy characteristics of sandy soils through different laboratory
tests. The soil was classified into three Units and some sub-units based on grain
size and SPT-N value. Soil parameters were finalized based on both laboratory
and field test results. The pile design was possible for accurate measurement of
soil parameters and ground profiling along the alignment of the bridge.
