The load bearing behavior of post-grouted bored piles were analyzed deeply

according to the static load test and stress testing results of test piles in a building and its nearby site. The top load-settlement relationships of post-grouted bored piles can be represented with power models; those of un-grouted bored piles can be represented with hyperbolic models. The ratios of base bearing ranges over 6.4 %—18.4 % after grouting

and the ratio increased sharply with the increasing of top loads. According to the extrapolated values

the ultimate load bearing capacities of piles grouted in the base or the shaft were increased 89.85 %—147.81 %

those grouted only in the base were increased 30.08 %—81.78 %. According to the results of gray relational analysis

the total grout quantity is the most important factor no matter which grouting method is applied

and the effect of base grouting is better than that of shaft grouting.