75 
Chapter V 
D) REPORT ON THE PARTICIPATION OF THE DEPARTMENT OF 
CIVIL ENGINEERING, UNIVERSITY OF ILLINOIS 
URBANA, ILLINOIS, U.S.A. 
Test N. 18 
by 
H. M. Karara 
1 — INTRODUCTION 
The participation of the University of Illinois in the program of the Study Group 
for Experimental Research on Blocks of Strips involved an analog triangulation of the 
Block Massif Central using a Wild A7 stereoplotter. «Test No. 18» was the title 
assigned to our work by the Presidency of the Group. FILM DIAPOSITIVES of 
eleven strips (three main strips and eight secondary strips) were used. A total of 188 
photographs, taken by a Zeiss RMK 15/23, c = 153.17 mm, were used. The photo-scale 
varied between 1:52 000 and 1:56000. The triangulation on the Autograph was 
executed according to the « Folgebildanschluss » method as an aeropolygon, in which 
the relative orientation was done according to von Gruber’s Assymetrical Method. 
The scale of the model in the autograph was chosen as 1:30000. The adjustment of 
the eleven individual strips was made according to the newly developed « Mini Me 
thod ». The block adjustment was executed according to the well-known Zeller’s 
Method. 
2 — DETAILS ON THE WORK 
The work on the block involved the following steps: 
2.1. Preparation. — This step involved the choice of ground control points as 
well as the selection, numbering and sketching of suitable pass and tie points. 
The following 43 points were chosen to control the three main strips (and thus 
the whole block): 3, 4, 5, 6, 19, 20, 22, 24, 40, 41, 42, 43, 79, 113, 121, 123, 134, 135, 
136, 138, 148, 150, 157, 158, 191. 193, 194, 214, 215, 216, 230, 248, 251, 252,264,