This report deals with various problems, which we have examined under preparation for design standards on port and harbour structures ; on values of coefficients of wall friction along backs of L-shaped concrete blocks, thickness of top concrete slabs on concrete caissons served as breakwater, a effect of deducing earth pressure with back filling, a effect of deducing anchor pull through bollards with concrete copping, and arrangement for rubber fenders.
　On coefficients of wall friction along backs of L-blocks ; when we examine the stability of L-blocks, it is safe and convenient to assume 15 degree as angle of wall friction along assummed back walls, and to regard assummed back walls vertical planes through heels of blocks. The proposition is examined with numerical calcutations based upon the Coulomb's earth pressure theory and designed examples.
　On thickness of top concrete slabs of breakewaters ; Investigating examples of constructed ones in Japanese ports and presence of their damage, we propose how much thick the top and covered concrete slabs should be, referring to assummed wave height.
　On a effect of deducing earth pressure with dack filling ; We calculate earth pressure on quay walls with back filling according to the Coulomb's earth wedge theory, which are many shaped and many seized, and whose internal friction angle range 35 degree to 45 degree. We figure the deducing ratio in charts, which of earth pressure on walls with back filling to ones without it are.
　On a effect of deducing a concentrated loads with a copping ; We calculate deformation and bending moment of elastically surported concrete beams under concentrated loads such as pull of ships through bollards and thrust of ships through fenders. Considering computed results, we propose the pull reaction to tie-rod usually are less than a quater of the pull.
　On arrangement for rubber fenders ; We investigate the distance between rubber fenders in typical Japanese ports, and propose the arrangement for them, classified with water depth in berthes, as follow.
　depth in berthes　distance between fenders
　　4m ～ 6m　　　　　　　4m ～ 7m
　　6m ～ 8m　　　　　　　7m ～10m
　　8m ～10m　　　　　　10m ～15m