They are using a different method. In their own words: "The presence of a water wave can be detected by feeling its up-and-down motion or by taking a picture of it. We are doing the latter." LIGO is doing the former.

http://bicepkeck.org/faq.html

LIGO has not failed. The second generation of LIGO detectors, called "advanced LIGO", is currently under construction. It will be around ten times more sensitive than the earlier configuration of LIGO, and is very much expected to yield astrophysical discoveries. More info at: http://ligo.org/

Furthermore, what LIGO seeks to do, and what the BICEP project has done, are quite different. LIGO is something like a "radio" that receives gravitational waves. We'll be able to listen to gravitational waves as they arrive at Earth. The discovery announced today is of the "fossilized" imprint of primordial gravitational waves on the cosmic microwave background radiation. Very important, but complementary to LIGO.