In a project of Guangzhou Metro, the main geology is full face fresh granite whose UCS reaches up to 150MPa, and parts of the geology is various upper soft lower hard ground. Such geological condition requires disc cutters to be wear resistant and tough enough as well. Following is the pictures of our disc cutters in boring.
White traces made by disc cutters in full-face granite.
Fresh granite at the bottom of the tunnel
Strong weathered granite at the top of the tunnel
After boring a long distance, our TBM disc cutters were still in good condition