Drivability of Reinforced Polymeric Piling

The drivability of conventional piling is mostly influenced by the soil parameters, because conventional piling materials are much stiffer than soils. However, the weight and modulus play an important role in RPP. Generally, an increase of the specific weight of the pile reduces the required number of blows. Also, members with a high composite modulus are easier to drive (Fig. 11).

Wave equation analysis (WEAP) of polymeric piling involves a number of variations from conventional analyses. The input parameter is used in WEAP are obtained via back analyses of actual case histories. The properties of RPP differ from those of conventional piling, so conventional WEAP input parameters might not work as well for RPP. Iskander and Stachula used available driving records to calibrate WEAP input parameters for composite piling. A secant modulus equal to two-thirds of the initial tangent modulus is recommended in order to account for the non-linearity of polymeric materials. Also, a damping ratio of 9 was found to best predict the field drivability.

The potential importance of residual stress analysis in WEAP analyses is illustrated in Fig. below