Generalized Models for Rock Joint Surface Shapes

Figure 4

Typical profile curves of joint surface (sample size is 10 cm and scale is 1 : 2). ① Planar and smooth (carbonaceous slate foliation). ② Planar and rough (basaltic columnar joint). ③ Single stepped (coarse-grained granite joint). ④ Multistepped (volcanic breccia joint). ⑤ Slow undulating (fine-grained granite joint). ⑥ Undulating (siltstone ripple bedding). ⑦ Undulating (breccia-bearing fusion tuff joint). ⑧ Undulating (fine-sandstone joint). ⑨ Compound undulating (calcareous clay rock joint). ⑩ Compound undulating (calcilutite joint). ⑪ Planar-undulating (mixed hornblendite joint). ⑫ Stepped-undulating (calcareous clay rock joint).