PURPOSE: To make processing efficient by a method wherein data for Poisson's ratio of a bedrock, the inner radius of a bore, displacement and load are inputted into a microcomputer, said data are graphically displayed on a display screen and coordinates displayed on the screen are stored, and bedrock strength criteria are taken out from the stored data by computation or conversion.
CONSTITUTION: A microcomputer 1b is attached to an underground load tester 1a through an interface 1c. A characteristic graph Pt comprising displacement R and load P is displayed on a screen of a display unit of the microcomputer 1b and each of coordinates (AR, Ar), (BR, Br), and (CR, Cr) made by an automatically set load point A, a point B where proportional relation starts and an optional point C in continuation of the proportion are stored in the microcomputer. Based on these memorized data, equations (BP-Ar)/(BR-AR)=α1, (Cr-Br)/(CR-BR)=α2, (AR+BR)/2=Rm1 and/or (BR+CR)/2=Rm2 are made by computation and are stored. Furthermore, based on the above stored data, equations (1±)×Rm1×α1=DbI, (1±)×Rm2×α2=DbII, Br=PImax, BR=δImax or/and CR-(CP/α2)=δ0 are made by computation or conversion, and bedrock strength criteria such as DbI, DbII, PImax, δImax and/or δ0 are computed. In the underground load test, CR-(CP/α2)=δ0 is made BR-(Br/α2)=δ0.
SATO ETSURO
EGAWA KEIJI
