PHOTOGRAMMETRIC DETERMINATIONS ON EQUIVALENT MODELS 
IN MINING INDUSTRY STUDIES 
Dan Radulescu 
College of Civil Engineering, Bucarest 
ABSTRACT 
The paper presents the methodology of’ 
photogrammetric determination of the displacee 
ments of points observed on the equivalent 
models in the studies of strata deformation 
for mining works. 
The determinations are performed by ae 
nalytical processing of the measurements. In 
the paper are presented the main work stages 
and the obtained results,as well. 
1.Introduotion 
The que tou Lao sonant où) study of the 
geotechnical structures im mining industry 
researches = as they are performed on the 
equivalent models - involves a great amount 
of mesurements for a large number of points. 
By subsequently processing of the es» 
tablished displacements of the model points 
at different time intervals, the qualitative 
and quantitative features of the Studied phe- 
nomenon on a certain model are determined. 
The choice of a photogrammetric method 
for establishing the model points displace- 
ments is based on the following reasons: 
= the large number of observed points 
for a better understanding of the studied phee 
nomenon; 
^ the diffioulties of performing direot 
measurements becmuse of time and space condi- 
tions of the experiments; 
« the possibility of reducing the worke 
ing period on the model, by posteprocessing of 
the photogrammetric records; 
= the increased precision of the indi- 
rect determinations as against the direct mese 
surements on the model. 
The studies of the deformations of geoe 
technical structures due to mining works, pere 
formed under simulated conditions on the equi~ 
valent models, are mainly based on the knowing 
50 
ef the incremental bidirectional displacements 
ef a certain number ef marked points wich are 
located in the frontal plane ef the modol/l/. 
In such conditions the most efficient method 
consists ín exploiting the projective cerrespe 
endence between the frontal plane of the model 
and the planes of the photograms taken over 
$he different parts of the model, at different 
time intervals. Each photogram must be contre» 
led by least four points having knewn coerdie 
mates in the frontal plane ef the model. 
The determination of the model points 
displacements is performed by analytical pres 
cessing of the photegrammetrio observations. 
The coordinates of the required control poi- 
nts of the model are established by analyti- 
- cal photogrammetric methods,as well. 
2 cAnalytical precess of ete =. 
metric_ data 
2.1.Determination of the coordinates of 
the p oints is perlormed In 
The zZirst [ 
two phases. ret one consists in determe 
ination of the space coordinates of the con- 
trol points into an arbitrary system of axis 
by means of a standard aerial-photogrammetriec 
procedure.The resulting coordinates are only 
scaled using the data offered by six or seven 
invar rods of precisely kmown length wich 
are located in the space of the studied equi- 
valent model. 
In the second phase, the resulted spe 
ace coordinates X,, Y,, Z4 of the control 
points are transf ymed so "they have to defi- 
ne a plane system of coordinates located in 
the frontal plane of the model. 
The applied transformation is a ro- 
tation performed under the condition 2. - 
sonatenti, according to the following proe 
cedure: 
a.- by solving the system of “errer 
equations” : 
where X, Y.o 2, are the space coordinates 
of the control points, the auxiliary para» 
meters A and B are obtained and subsequently 
the elements of the second row of the rotae 
tion matrix BR: 
Fay = Tap A 
be= by solving the following system 
of equations : 
for the auxiliary parameters C and D, the