6585845008

Bułgaria 25

the number of the rammer strokes on the anvil for penetratlon of the standard column 10 cm - and the soli type with the aid of tne formulae fort

-    gravel sand    E    =    8    - 9    (8)

-    sand    S    =    6,5 N_1Q + 3    (9)

-    olayey sand £ =6,7 JŁjq - 24    (10)

-    sandy clay    E    =    4,3 N^q - 27    (11)

-    clay    B    =    4 N_1q - 11    (12)

Analogically the modulus of generał deformation K_q is determined with the

aid of the formulse fort

-    gravel sand    B_Q    =    2 &|q + 2    (13)

-    sand    B_q    =    16 £₁₀ - 12    (14)

-    olayey sand    E_Q    =    17    - 80    (15)

-    sandy clay    B_q    =    11 1L|q - 88    (16)

-    olay    E_Q    =    9,5 N₁₀- 50    (17)

In the same Instruotion the interpreta-tion is deduoed from the data obtalned from operation with dynamie penetro-meter with tub ular tip*

The relation is also glyen for conyer-sion of the data IL₀ obtalned after operation with dynamio penetrometer -light typa. In another lssue is glyen a Table ln whloh, depending on the ^ at

operation with statio penetrometer Ir on &-₀ at operation with dynamie penetro-merer - light type and the type of the coherent soli, the admissible soli loadlng is glven ln kp/om² at admissible mean settlement of the bullding or oon-struction of about 5 cm* The results from the penetratlon for determining the carrylng capacity of the filling plles are used rarely.

N e e d 8 of futurę d e v e-lopment of testlng equipment and test-Ing methods

The penetratlon methods still contaln many unrevealed possibiUties for in-yeatigation of foundation soile* Thls will requlre further deyelopment of the ezperimental equipment* Our test shows that the slmple design of the eąuipment, without, of oourse, lmpalrlng lts accu-racy, renders posslbllities for less dama ges, fewer attendants, relatiyely better safety and lower costs*

Bor obtaining mutually oomparable results the basie parameter of the equip-ment used for inyestigation of foundation solid ln situ, should be standard-ized and beoome blndlng upon a 11 coun-tries*

We would welcome the standardization of the eąuipment and the methods for pene-tration on International leyel.

As we already mentioned, the respectiye standards and nozmatiye doouments are lssued ln Bułgaria*