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Poland

of static penetratlon are glven* Owlng to the llmlted use in Poland of statlo pe-netrometers It is accepted to make an interpretatlon according the orlteria used ln other countrles*

The oomplexlty of the glaoial deposits coyerlng the greater part of Poland'b terrltory reąuire mostly complez methods of subsurface exploration. In generał borings are used mostly ln Poland, how-ever reoently they are often aooompanled by penetratlon tests. The Interpretatlon of the stratlgraphy of the layers on the basis of penetratlon tests ls an import-ant problem, now under lnyestlgatlon*

Thls task was undertaken by M* Borowozyk and C* Królikowski of the Geologloal In-stltute ln Warsaw whloh oarrled out an lnyestigatlon wlth the unlversal probe whlcb they had deyeloped* The results of the penetratlon test done wlth the Dutob llght penetrometer aooompanled by the unlversal probe were used for-Interpretatlon of the stratlgraphy of the soli layers* An example of the results of both penetratlon tests performed at the distanoe 0,5 m are shown ln fig*9*

The subsurfaoe oondltlons at the inwes-tlgated slte were as follows: deltalo deposits oomposed of layers of mud, peat, sands and loams* In thls stratlgraphy the penetratlon tests are unable to unml8takably distlngulsh the layers wlth smali and large cone resistance* The data obtalned from the unlversal probe proYldes a substantlal advantage ln cor-rectly lnterpreting penetratlon results* The dlfforences of denslty and molsture whloh dlfferentlate peat and mud layers from sand and loam layers estimated by means of unlversal probe oorrelated well wlth Duob penetrometer results* It was aiso found that there was oorrelatlon between the cone resistance and the spe-clflo resistanoe measured by the univer-

eal probe*

70    30    40    50

| moisture %

Fig 9. The results of the unlversal probe test aooompanled by statlo pene-tration test*

On the basis of the above mentloned In-yestlgatlon lt oould be asumed that unlversal probe will be useful also in penetratlon test ln ooheslve solls* The oomparlson of the data obtalned from the dynamie penetratlon tests and from borings show a lack of oorrelatlon*Par-tloularly when the soli is plastlo the porę water Influence makes the testing results unreliable* As a result of thls only relative Information regardlng the stratlgraphy of the layers was deduoted from penetratlon in oohesive solls* The addltlonal data obtalned by means of the uniyersal probe are essentlal for interpretatlon of the sounding in coheslye solls*