解:∵CE=30m,AD⊥BC,∴AD=CE=30m,∵∠DAC=45°,∴AD=CD=30m,在Rt△ABD中,BD=AD×tan∠BAD=30× 3 =30 3 ,∴BC=CD+BD=30+30 3 (m).故答案为:30+30 3 m.