Plugged honeycomb structure

A plugged honeycomb structure comprising:

• a plurality of prismatic columnar honeycomb segments;
• a bonding layer bonding side surfaces of the plurality of honeycomb segments to one another;
• and
• plugging portions arranged in open ends of predetermined cells in an inflow end face of each honeycomb segment and arranged in open ends of residual cells in an outflow end face thereof,
• wherein each honeycomb segment has porous partition walls arranged to surround a plurality of cells extending from the inflow end face to the outflow end face, and segment circumferential walls arranged at an outermost circumference,
• in a cross section of the honeycomb segment which is perpendicular to an extending direction of the cells, at least two types of cells having different shapes are formed to constitute predetermined repeated arrangement patterns,
• the cells of the honeycomb segment include rim circumferential wall cells,
• the rim circumferential wall cells are the cells having rims surrounded with the partition walls and the segment circumferential walls,
• the rim circumferential wall cells include corner rim circumferential wall cells and non-corner rim circumferential wall cells,
• the corner rim circumferential wall cells are the rim circumferential wall cells arranged in corner portions of the honeycomb segment,
• the non-corner rim circumferential wall cells are the rim circumferential wall cells arranged in portions other than the corner portions of the honeycomb segment, and
• an inflow open area S1in of each corner rim circumferential wall cell is 1.1 times or more as large as an average inflow open area S2in of the non-corner rim circumferential wall cells, or
• an outflow open area S1out of the corner rim circumferential wall cell is 1.1 times or more as large as an average outflow open area S2out of the non-corner rim circumferential wall cells.