A new rigorous analytical solution is deduced from the equivalent strain governing equation for the consolidation by vertical drains on the basis of the assumption proposed by Deng et al(2013), that is, the well resistance increasing linearly with depth and exponentially with time. The solution is verified through the comparison with the results got from the existing analytical solution, in which the well resistance remains constant. Based on the new solution, the average excess pore water pressure and aver...