266371450

PROJEKT LOCATIOM SECTION/HOLE no						SMEET NO OATE OPERATOR
ElEvATlONS GROLWO SuRFACE GWUND wAlfp UBiE : RFffOfurę iCwCt
PURPOSE 0F TEST					TYPE:
ECUIPMENT CYN AM C PBOftlNG ROD CASiNG BONT ORllNGFlUiC
OEPTM 0ELOW AEFEPENSE LfVEl m	*9	HFiGHT O F PAU	NUMBER OF BLOWS PER 0.2 r*	NOTATlONS INTFRRUPTlONS. ROTATlON. SOUNOS REASON FOR TERMINATING ROD SnAP£
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Fig. 3 Example of site log from dynamie probing.

The probing results shall be presented in diagrams which show the N^- or the N_B-values on the horizontal axis and the depth on the vertical axis. At each depth the mass of the hammer and the height of fali shall be. given. The type of test must be indicated and the reason for terminating the test.

It can be advantageous to transform the N_d-values to resistance values r_d or q_d from one of the equations given in 1.1.

An example of the presentation of test data is shown in Fig. 4.

5. PROCEDURES OUTSIDE THE REFERENCE RANGĘ

The penetration resistance with dynamie probing is within the reference rangę when 5 to 100 blows are required to drive the penetrometer 0.2 m. The rebound at each blow should be less than 50% of the penetration at the blow.

It is desirable to carry out dynamie probing also outside the reference rangę in a regu-lated way: If morę than 100 blows are re-quired for 0.2 m of penetration or the rebound is excessive it is recommended to inerease the height of fali to 1.0 m. If the rebound is excessive even after the height of fali has been inereased, it is recommended that the mass of the hammer is inereased to 127 kg. When the penetration resistance is less than 5 blows per 0.2 m of penetration it is recommended to reduce the height of fali to 0.5 or 0.25 m in order to inerease the sensitivity of the method.

Outside the reference rangę, when the height of fali or the mass of the hammer is changed, the penetration resistance is given as Nó-values (N^_a and n^_b respectively).

It is unlikely that a point with a 60° apex angle will give probing results very differ-ent from one with a 90 apex angle. A cone of 60° is permitted if noted in the probing log.

LEGEND: BOREHOLE NUMBER

ELEYATIONS *9 35. *10. *5. tO

TYPE 0F PROBING DPB

5 STANDARD MASS AND HEIGHT 0F FALL M MASS IN kg OT HER THAN STANDARD.

H HEIGHT 0F FALL OT HER THAN STANDARD *    TURNING 0F ROD

110    NUMBER OF BLOWS EXCEEDING 100

^NdB BLOWS PER 20cm TEST TYPE B. ^rdB SPECIFIC RESISTANCE VALUE Pa NO MEASUREMENT MADĘ.

N_d- VALUES r_d- VALUES

SYMBOL FOR ENDING 0F PROBING

Fig. 4 An example of the presentation of test results from dynamie probing, DPB.

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