Abstract
When several joint systems are developed in rock masses, different deterioration conditions along those joints are often observed. This shows that those rock masses are different in stages of deterioration. As for the deterioration along the joint surface, the following process is recolgnized in general; from fresh part to weathering part, “fresh joint surface→brown pollution of joint surface→progresses of rock mass weathering”. From such phenomenon, brown pollution along joint surface may be regarded as a phenomenon of initial stage of weathering in fractured rock. In this paper, it is tried to grasp the deterioration tendency of joint by describing the brown pollution conditions on each joint surface. As a result, it was confirmed that the following joint deteriorated, “the joint that was formed by most late geological age tectonics”, “low angle joint distributed present or past groundwater surface neighborhood”.
