Abstract: This paper presents a case history of quality assurance and quality control testing of Cement-Fly Ash-Gravel (CFG) Column composite ground in Shangdong Wanhe Project and a soil improvement project in the eastern district of Zhangjiakou Bridge. The subsurface soil strata are introduced and the end bearing CFG column is located in the gravelly soil stratum. Then the low-strain integrity testing instrument equipment diagram, several frequently encountered integrity test results types, basic principles and the essential static loading test devices are introduced. The bearing capacity evaluation of the CFG columns in the Shangdong Wanhe No.7 Building is divided into two steps: the first step is the column integrity testing, the second step of is the static loading tests on the composite ground (including column and it surrounding soils) as well as on the single column. The testing results are evaluated. The column installation integrity as well as bearing capacity of the composite ground evaluated throughout the low-strain test results and load-settlement (Q~s) curve of static loading test results. The results are satisfactory. The results also indicate that the low-strain test technique is needed for the improvement.

Key words: GFG Columns, Low Strain Integrity Tests, Static Loading Tests