Two-flux Colliding Plane Waves in String Theory
  We construct the two-flux colliding plane wave solutions in higher dimensional gravity theory with dilaton, and two complementary fluxes. Two kinds of solutions has been obtained: Bell-Szekeres(BS) type and homogeneous type. After imposing the junction condition, we find that only Bell-Szekeres type solution is physically well-defined. Furthermore, we show that the future curvature singularity is always developed for our solutions. 
Bin Chen and Jun-Feng Zhang