COMPARATIVE ANALYSIS OF UNDISTURBED SOIL SAMPLE QUALITIES WITH DIFFERENT SAMPLING METHODS IN A SITE IN SHIJIAZHUANG,HEBEI PROVINCE

Primary state soil sampling is an important tache in engineering exploration,different sampling method has different affection to the quality of soil sample.Generally speaking,the big primary soil sample collected in shaft is the true primary state soil sample,the sample collected by soil collected equipment in drilling is of different degree disturbance.The disturbing degree is different with different sampling method in drilling hole.Through comparative analysis to the test data of tow sampling methods in drilling hole and sampling method in shaft,it was found out by the author that the drilling sampling method has obvious disturbance and depression to the soil sample,which caused the soil samples dry density to be increased,porosity ratio to be decreased,filtration coefficient to be decreased,and modulus of compression to be increased.Meanwhile,it was found out that the sample quality collected with fast irruptive is slightly better than samples quality collected by upper irruptive.In order to ensure the safety of engineering,it should be careful to use the test result of normal drilling sampling,the pitting sampling,shaft sampling,or double-tubles and thin-wall soil collecting methods should be used.