ICPTT 2011 [electronic resource] : sustainable solutions for water, sewer, gas, and oil pipelines / by Ma, Baosong editor, Najafi, Mohammad, editor, Jiang, Guosheng ditor, Salvin, Larry editor, American Society of Civil Engineers, International Concerence on Pipelines and Trenchless Technology ( October 26-29, 2011 : Beijing, China)