  We describe the detailed study and results of high-resolution numerical
simulations of string-induced structure formation in open universes and those
with a non-zero cosmological constant. The effect from small loops generated
from the string network has also been investigated. We provide a
semi-analytical model which can reproduce these simulation results. A detailed
study of cosmic string network properties regarding structure formation is also
given, including the correlation time, the topological analysis of the source
spectrum, the correlation between long strings and loops, and the evolution of
long-string and loop energy densities. For models with $\Gamma=\Omega
h=0.1--0.2 and a cold dark matter background, we show that the linear density
fluctuation power spectrum induced by cosmic strings has both an amplitude at
$8 h^{-1}$Mpc, $\sigma_8$, and an overall shape which are consistent within
uncertainties with those currently inferred from galaxy surveys. The cosmic
string scenario with hot dark matter requires a strongly scale-dependent bias
in order to agree with observations.
