bracketsangle bracketsconsolesdǒugǒngfúbìgǒngángyǐnggǒnglūmāśīrṣastambhaśīrṣajiǎ’ángyìxínggǒngyìxínggǒngchāgǒnglìnggǒngbǔjiān pùzuòhuāgǒngdīngtóugǒngshuǎtóubracketsspanning and projecting structural elementsbracket