Journal of Geographic Information System, 2010, 2, 23-31
doi:10.4236/jgis.2010.21006 Published Online January 2010 (http://www.scirp.org/journal/jgis)
Copyright © 2010 SciRes JGIS
Geospatial Analysis of Geotechnical Data Applied
to Urban Infrastructure Planning
Rodolfo Moreda MENDES1, Reinaldo LORANDI2
1Geological Institute, Secretariat of Environment, Avenida Miguel Stefano n 3900, São Paulo, Brazil
2Civil Engineering Department, Federal University of São Carlos, Rodovia Washington Luis, Km 235, Sã o
Carlos, Brazil
Email: rodolfo.mendes@igeologico.sp.gov.br, lorandi@ufscar.br
Abstract: The urbanization process inside the State of São Paulo (Brazil) facilitated, in approximately five
decades, the migration of thousands of peasants to the urban areas of great industrial centers inducing and
requesting, at the same time and very often, an amplification of the systems of local urban infrastructure not
appropriate for the natural potential of the physical territory. In this content, the city of São José do Rio Preto
(State of São Paulo) with little more than 350.000 inhabitants, currently faces serious problems related to the
urban planning originating from the unusual occupation and without previous study of suitability. Therefore,
the present paper intends to guide and indicate the areas whose potential of urban development leads to an
occupation suitable for the construction of shallow foundations in residential buildings of single floor, using
an interpretative chart produced by the software GIS-SPRING-4.0 developed by Instituto Nacional de Pes-
quisas Espaciais/INPE (Brazil), and based in the methodology of geotechnical mapping developed by the de-
partment of geotechnical engineering of EESC/USP (Brazil). The chart for shallow foundation shows that a
large portion of the studied area presents serious relationship problems with layers of highly collapsible soils.
Keywords: GIS, geotechnical mapping, urban planning, urban infrastructure, shallow foundations
1. Introduction
Industrialisation in underdeveloped countries is an im-
portant part of participation in the urbanization process.
We can consider industry as one of the great causal fac-
tors of urbanization, and, for this reason, industrialized
areas are also the most urbanized. As several examina-
tions have shown, the interior of the State of São Paulo
(Brazil) has presented the most significant rates of popu-
lation growth in the entire state in the last decade (Negri
and Pacheco, 1993; Caiado and Vasconcelos, 1994;
Campolina Dinis and Santos, 1995).
The migration process to the interior of the State of
São Paulo is related to the intervals of proximity to the
metropolitan area of the city of São Paulo, according to
Birkholz et al. (1983). In the interval of proximities, the
important urban centers of Ribeirão Preto, Presidente
Prudente, Bauru and São José do Rio Preto are included.
The city of São José do Rio Preto (State of São Paulo) is
located at an important railway and roadway east-west
axis of the State of São Paulo, which offers conditions
for its growth, and is set fundamentally in the tertiary
sector. However, the constitution of new industrial and
agriculture-industrial spaces in the interior of São Paulo
was not capable of avoiding the collapse of the basic
urban public infrastructure in the development process.
This view shows the current situation of the city of São
José do Rio Preto, composed mainly of an irregular pat-
tern of single floor residential constructions, which have
foundations and urban infrastructure in places that lack
previous suitability studies. These often do not satisfy the
natural relationship potentials of the urban physical ter-
ritory/ocupation.
Therefore, in this paper a space analysis of the main
attributes of the physical territory of the urban center
area of São José do Rio Preto was prepared, with the
intention of obtaining, using the database produced by
Mendes (2001), interpretative charts for shallow founda-
tions and underground constructions that can evaluate
and indicate areas where potentials of urban physical
territory are adapted in an efficient way. The objective
was to minimise or repair the current problems of ir-
regular urban occupation. These interpretative charts can
guide local investigations, allowing us, in certain cir-
cumstances, to decrease costs, time and the number of
situations to be studied and investigated.
2. Area of Study
The studied area (Figure 1) is located in the Western
R. M. MENDES ET AL.
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24
Figure 1. Location of the studied area (Mendes 2001)
Region of the State of São Paulo (Brazil), between the
parallels 20º47'00" and 20º51'10" South and the meridi-
ans 49º24'58" and 49º20'13" West, possessing an area of
60.0 km2. According to Brazil-IBGE (2001), the city of
São José do Rio Preto presents, in the census of 2000,
total and urban populations of 357.862 hab and 336.998
hab, respectively. The resident population in the munici-
pal seat and the demographic density are, respectively,
326.627 hab and 827 hab/Km².
According to Arid (1966), the studied area is classified,
as a humid tropical climate that possesses annual me-
dium temperatures around 25.4ºC. A general view of the
vegetation shows that it is composed of 10.4% perma-
nent cultures, 18.9% annual, 52.9% grassland, 7.9% for-
ests and 9.9% lazy and reforested lands. In the developed
area pedologic formations prevail with thick soils repre-
sented by red-yellow latosol and yellow latosol. On the
slopes of the main valley and in end northeast of the area,
stains of red-yellow latosol intergrade argisol appear,
representing an intermediary level of pedologic evolu-
tion.
The gleisols distributed along the valleys of the main
drainage lines can be associated with conditional specific
geotechnics as profile organic clays of low bearing ca-
pacity and shallow level of water, with direct influence
on the geotechnic properties of the soil aggregate. The
other pedological units, such as argisols and cambisols,
have restricted occurrence in the study area (Augusto
Filho, Ridente and Alves 1999).
According to Barcha (1980), in the studied area the
soils sufficiently favour infiltration conditions due to
their grain size distributions. They are, for the most part,
sandy soils of the Adamantina and Santo Anastácio for-
mations, both belonging to the Bauru group (Cretaceous)
where the sand fraction always prevails (± 70%), varying
the fine grain size, with a clayey silt fraction around 30%.
The Adamantina formation is composed of fine sand-
stone; quartzose with clayey particles; cementation car-
bonaceous with plan-parallel stratification and crusades
of medium load; clay banks with a massive,
brown-reddish tone and recent sediments of the Quater-
nary composed of fine sand alleviation with beige and
light gray tones; and sandy and/or silty clay with light to
dark gray tone. The Santo Anastácio formation appears
R. M. MENDES ET AL.
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25
in areas that accompany the quotas with more drops in
the river and streamlet valleys, represented by brown-
reddish and violet tones of sandstone with fine to me-
dium grain size, generally regulated to bad grain size
distribution and rounded particle size covered by limo-
nitic film. On the surface of the studied area only the
Adamantina formation appears at the depth of the Santo
Anastácio formation. The Adamantina formation is more
expressive, with a thickness varying from 58 meters up
to 140 meters. The rocky blooming is relatively rare,
occurring mainly in the drainage lines.
According to the geomorphological division of the
State of São Paulo (São Paulo - FFLCH/USP-IPT-
FAPESP, 1997), the studied area is located in the mor-
phostructural unit of the Parana sedimentary basin that
embraces a morphosculptural unit, denominated “west-
ern tableland from São Paulo”, and presents the fol-
lowing characteristics: the unit occupies almost 50% of
the total area of the State of São Paulo, and the relief of
this morphosculpture is, in general, slightly waved with a
prevalence of wide and low hills with leveled tops. Other
characteristics are medium dimensions between drainage
lines of 1.750 to 3.750 meters and a medium slope be-
tween 2 and 10%. The topography of the studied area is
smooth, and the relief is waved and relatively uniform,
with wide and low hills (Barcha, 1980). The level dif-
ferences presented by the greater amounts of discharge
and the lower altitude, which varies from 350 to 550
meters, are small.
3. Methodology and Materials
A geospatial analysis of the main geotechnical attributes
of the urban physical territory of the city of São José do
Rio Preto was performed based on the methodology of
geotechnical mapping developed by the geotechnical
engineering department of EESC/USP (Brazil) and using
a Geographical Information System (GIS-SPRING) de-
veloped by Instituto Nacional de Pesquisas Espaciais/
INPE (Brazil).
For the interpretative chart, pre-existing information
was used, represented by the SPT – Standard Penetrating
Test (1500 boreholes, approximately, in 241 building
sites), in addition to collections in the field of disturbed
and undisturbed samples for laboratory analysis, which
allowed us to determine the geotechnical properties of
the unconsolidate materials, such as grain-size distribu-
tion, Atterberg limits, permeability, expansibility, com-
pressibility and collapsibility. This study also relied on
the production of several intermediary cartographic doc-
uments.
Firstly, the boreholes that represented the profile of the
land based on the largest investigated depth or largest va-
riability of the layers of the soil aggregate were selected,
facilitating the assembly of a geographical database con-
taining all of the information from the borehole profiles.
Later on, a study of the existence or non-existence of
correlation was performed with the data originating from
pre-existent boreholes, such as texture, the bearing ca-
pacity of the layers for NSPT and groundwater levels, with
the geotechnical properties determined in laboratory. We
later made a comparative analysis of the boreholes that
presented properties similar to the soil aggregate, attrib-
uting the values of those properties to regions whose
geotechnical behavior could be considered homogeneous.
Starting from the information contained in the database,
it was possible to esteem the values for each attribute in
places without sampling by using the geostatistical
methodology of the ordinary kriging for the module of
the spatial analysis implanted in the GIS-SPRING-4.0,
based on the subroutine “kt3d” of GSLIB (Deutsch and
Journel, 1992).
Therefore, the geotechnical properties of the uncon-
solidated material and the values of the attributes ob-
tained by the geostatistical methodology of the kriging
were used, and the intermediary charts (bearing capacity,
groundwater level, texture, drenability, organic layer,
depth of the impenetrable to SPT and collapsibility) were
elaborated. Starting from the information of those inter-
mediary charts, the interpretative chart of shallow foun-
dations, with its respective suitability classes according
to adopted methodology, were obtained.
The methodology used in the elaboration of the inter-
pretative chart was based on the attributes of the urban
physical territory and limits proposed (Zuquette, 1987,
1993). Those limits were defined starting from the ex-
perience of works developed in several areas of Brazil
and using the information obtained through the referred
author’s bibliographical, where the homogeneity of the
terrain (in terms of areas) was described in suitability
classes (Favourable, Moderate, Severe and Restrictive)
that reflect the degree of difficulty in the introduction of
buildings in the terrain. Considering the objectives, the
attributes, its occurrence levels and purposes were de-
fined according to Zuquette (1993), and four suitability
classes were used in that mapping:
a) Favourable: the totality of the attributes presents
appropriate levels, where two attributes of secondary
importance present levels that would place them in the
moderate class. The favourable class means that the nec-
essary technological resources for the occupation or con-
struction will be the simplest and most inexpensive; the
potential of negative impacts and of risks will be the
lowest within the studied region;
b) Moderate: 80% or more of the fundamental attrib-
utes present compatible levels with the moderate and
favourable classes. In areas classified as moderate, there
are possibilities of the occurrence of negative impacts
and risks. During the occupation or construction there
can be a need for more onerous operational and techno-
logical resources with a certain degree of complexity;
c) Severe: 15% of the attributes present compatible
R. M. MENDES ET AL.
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26
levels with the moderate and favourable classes, and at
most 15% are in the restrictive level. An area classified
as severe presents concrete possibilities in the occurrence
of negative environmental impacts and of risks. It can
also demand expensive and complex operational and
technological resources for construction or occupation
when compared to the favourable class;
d) Restrictive: only 20% of the attributes present lev-
els that characterise them as favourable, moderate or
severe. The framed areas in this class should be occupied
with the largest care because they will demand complex
and onerous technological resources and could affect
revenue, due to the problems that could happen, such as
the negative environmental impacts and possibilities of
risks.
Table 1 shows the attributes and their pertinent occur-
rence levels in the suitability classes that were used in
this paper for the elaboration of the interpretative chart of
shallow foundations.
4. Results
To obtain the physical indexes, Atterberg limits, grain-
size analysis, blue methylene adsorption test, mini-CBR
and mini-MCV tests were used on the disturbed samples
of the unconsolidated materials collected in five different
places at depths of 1.0, 2.0, 3.0 and 7.0 meters. The
points were numbered according to location in the plant
(P1, P2, Pi) and collection depth (A at 1.0 m of depth, B
at 2.0 m, C at 3.0 m and D at 7.0 m). Therefore, the sam-
ple of place P1A represents a disturbed sample collected
in place 1 at a 1.0 meter depth.
The tests, traditional geotechnical classifications and
determination of physical indexes of the soil aggregate,
such as grain-size analysis, unit weight of the soil parti-
cles and Atterberg limits, were obtained in agreement
with the effective norm of the Brazilian Association of
Technical Norm (ABNT).
The geotechnical properties of the materials were dete-
rmined from tests and/or empirical correlations, accord-
ing to the effectiveness and credibility of the same ones.
The permeability was esteemed according to the empiri-
cal correlation proposed by Honorato and Mackenna
(1975) for special conditions:


2,19735
50
8,50784
14, 266
d
D
k
(m/s)
k” is in m/s; “D50” in mm and “ρd” in g/cm3. This rela-
tionship is an expression that allows us to estimate the
permeability in the superficial soils (in the case of 1 to 3
meters in depth) by measuring D50 and the natural dry
unit mass “ρd”. The composition grain size soil aggregate
of the studied area is composed of approximately 65%
fine sand fraction, followed by 25% clay fraction and
10% silt fraction, except for the sample P4D, where the
increment of the silt and clay fractions indicate the pres-
ence of saprolite soil (residual young soil). Therefore, it
is classified as (ABNT) small silty clayey fine sand.
Comparing the results of grain size analysis performed in
the laboratory (Table 2) with the boreholes available in
the studied area, a strong relationship texture was carried
out, mainly for the first 5.0 meters of depth. The perme-
ability coefficient values do not possess a considerable
space variability, once medium values meet between
7.510-3 and 10.410-3 m/s and the soil texture is rela-
tively homogeneous in the analyzed depths.
The expansibility was obtained by the analysis of the
results of the blue methylene adsorption test, according
to concepts established by Hang and Brindley (1970) for
that test, used by Pejon (1992) and correlated with the
MCT classification (Costa and Gandolfi, 1998) for use in
geotechnical mapping, making use of the Mini-MCV and
Expansion/Drying shrinkage (Mini-CBR) tests, accord-
ing to Nogami and Villibor (1979). The expansion po-
tential of soil of the studied area was verified first with
the MCT classification, using the Mini-MCV and Mini-
CBR tests.
The clayey fraction present in the unconsolidated ma-
terial is largely responsible for its behaviour not only for
the amount of present clay in the soil but also for the
quality and expansion potential of the present deleterious
clay minerals in the clay fraction, so it was thought best
to complement that test using the blue methylene adsorp-
tion test because it takes into consideration the physical-
chemical behaviour of the fine fraction of unconsolidated
material with geotechnical purposes (Pejon, 1992).
Table 1. Attribute occurrence levels for the chart for shallow foundations
LEVEL
ATTRIBUTE
Favorable Moderate Severe Restrictive
Strength (until 5m) NSPT > 15 10< NSPT <15 6< NSPT <10 NSPT < 6
Collapsibility
Collapse Potential (CP) CP < 1% 1 < CP < 3% 3 < CP < 5% CP > 5%
Ground water level > 5m 3 to 5m 2 to 3m < 2m
Declivity < 5% 5 to 10% 10 to 20% > 20%
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27
Table 2. Laboratory results of the MCT classification and blue methylene adsorption test
Mini CBR Test Blue methylene adsorption test
Grain size analysi
(%) s Wopt d Expans.MiniMCT VB ACB CTCSOIL CTCCLAY
Samples
Sand Silt Clay (kN/m3) (%) (kN/m3)(%) CBRGroup(g/100g)(g/100g) (cmol+/Kg) (cmol+/Kg)
P1A 66 10 24 27,3 14,3 18,2 0,05 14,5LA' 0,74 3,1 2,3 9,7
P1B 62 10 28 27,5 15,5 18,0 0,09 14,0LG' 0,81 2,9 2,5 9,1
P1C 63 10 27 27,5 16,0 18,0 0,05 15,0LA' 0,91 3,4 2,8 10,5
P2A 68 6 26 27,6 13,3 18,3 0,02 14,5LA' 0,64 2,5 2,0 7,7
P2B 68 6 26 27,5 15,3 18,2 0,02 9,5 LA' 0,62 2,4 2,0 7,5
P2C 66 6 28 27,6 15,0 18,3 0,05 17,0LG' 0,55 2,0 1,7 6,2
P3A 65 5 30 26,9 14,0 18,5 0,03 13,1LA' 0,62 2,1 1,9 6,4
P3B 66 8 26 27,2 13,5 19,0 0,01 11,0LA' 0,53 2,0 1,7 6,4
P3C 67 7 26 27,9 13,5 19,2 0,07 15,0LA' 0,75 2,9 2,3 9,0
P4A 66 10 24 27,3 13,0 19,1 0,07 13,7LA' 0,46 1,9 1,4 6,0
P4B 66 8 26 27,3 13,0 19,2 0,06 14,5LA' 0,57 2,2 1,8 6,9
P4C 68 9 23 27,7 13,8 18,3 0,04 17,0LA' 0,45 2,0 1,4 6,1
P4D 53 16 31 27,8 17,0 18,2 0,09 16,5NA' 1,08 3,5 3,4 10,9
P5A 65 8 27 27,3 13,5 18,5 0,06 12,5LG' 0,61 2,3 1,9 7,1
P5B 65 7 28 27,5 14,0 19,2 0,05 9,5 LA' 0,66 2,4 2,1 7,4
P5C 67 5 28 27,4 13,0 19,3 0,08 15,0LA' 0,74 2,6 2,3 8,3
The expansion values obtained by the MCT classifica-
tion according to Costa and Gandolfi (1998) is shown in
Table 2, as well as the values of the natural dry unit
weight (γd) and optimum water moisture (wopt), unit
weight of the soil particles (γs) and Mini-CBR. Table 2
shows that the preponderant MCT classification is LA’
group, followed by the LG’ and NA’ groups, respec-
tively. Disregarding the appearance of the NA’ group
(sample P4D), which was collected at the exceptional
depth of 7.0 meters, the classification of the soil appears
to be exclusively of the sandy lateritic group followed by
the clayey lateritic group. The soils belonging to the
sandy lateritic group (LA’) are typically sandy and con-
stituent of the horizon B of the soils well-known pe-
dologically in Brazil for sandy latosol and argisols or
sandy argisols.
Later, the method of blue methylene adsorption was
used to establish a relationship among the MCT classifi-
cation according to Costa and Gandolfi (1998), attempt-
ing to relate the behaviour of the soils of the studied area
with its mineralogy obtained through of blue methylene
adsorption test. Working directly with the values defined
by the method of blue methylene adsorption, that is to
say, the values of blue methylene adsorpted for 100 g of
soil (VB) and for 100g of clay (ACB), they tried to corre-
late the values of VB with the MCT classification results.
This classification used to evaluate the studied soils pre-
sented lateritic or non lateritic behaviour and the type of
present deleterious clay mineral in the clay fraction of
the soil with base in the consumption of blue methylene
adsorpted for 100 g of clay (ACB). The values VB and ACB
can be observed directly in Table 2 for each soil sample.
According to this methodology, the soils present lateritic
behaviour for values of VB<1.0 and non lateritic behav-
iour for values of VB>2.5. It is concluded that all the soil
samples analyzed previously belong to soils of a group
with lateritic behaviour.
Other information could also be obtained starting from
the values of ACB about the most probable composition
of deleterious clay mineral in the clay fraction of the
studied soil. According to the diagram of activity of the
clay for the method of blue methylene (Lautrin, 1989)
and of the results of ACB for the analyzed soil, we ob-
serve that the type of clay mineral more probable and
present in the clay fraction of the analyzed soil is of the
caulinita group, considered not deleterious. A summary
of the values of VB and ACB, in function of the clay frac-
tion present in the studied soil can be seen in Figure 2. In
that figure the concentration of the samples “in black
circle”, presenting lineal behaviour of the percentage
clay fraction as a function of the values of VB and ACB, is
probably due to the presence in the clay fraction of soil
with clay minerals of the kaolinite type. It is also noticed
that for values of relatively high and low VB and ACB,
shown by “black arrows”, the values of the clay fraction
percentage of soil remains proportional to the increase in
R. M. MENDES ET AL.
Copyright © 2010 SciRes JGIS
28
% Fraction Clay
22,909
23,818
24,727
25,636
26,545
27,455
28,364
29,273
30,182
31,091
Figure 2. Surface graphic 3D to VB, ACB parameters versus
percentage fraction clay (Statistica/2000)
increments and decrease of those values, determining the
presence of non expansible clay minerals of the kaolinite
group. Therefore, it was verified that the expansibility
potential of the studied soil is very small and almost
worthless for use in geotechnical mapping, and we chose
not to consider that property in the making of the inter-
pretative chart.
The collapse potential (CP) was obtained for oedomet-
ric testing according to ABNT norm using undisturbed
samples of the soil collected at several depths. For ob-
taining the collapse potential, the specimens were sub-
mitted to the stress stages of 6, 12, 25 and 50 kPa, ac-
cording to procedures of the consolidation conventional
test. After the verification of stabilization deformations
for the stress stage of 50 kPa, the specimens were inun-
dated, and after 24 hours of the inundation stage the
variation void ratio of the soil specimens was verified.
Soon after, the specimens were submitted to new stress
stages of 100, 200 and 400 kPa. In some specimens the
stress stage of 800 kPa was increased. This way, the col-
lapse potential (CP) was obtained starting from equation
bellow, according to Jennings and Knight (1975):

0
100
1
C
e
CP e

(%)
where Δec = variation of the void ratio due to inundation,
and e0 = natural void ratio of the soil specimens.
It should be highlighted that the collapse potential de-
fined according to Jennings and Knight (1975) is ob-
tained starting from the inundation of specimen in the
stress stage of 200 kPa, but it was verified that in that
stress stage the collapse potential was considerably sma-
ller for the analyzed specimens.
Therefore, it was necessary to modify the stress stage,
decreasing the pressure from 200 kPa to 50 kPa, for the
specimen inundation stage. The values of the collapse
potentials (CP) due to the inundation obtained in the
stress stage of 50 kPa, as well as the values of the com-
pression index “cc” and the consolidation index “cv” of
the specimens of analyzed soil, are shown in Table 3,
where “CPe0” represents the obtained collapse potentials
using the natural void ratio of the soil specimens, and
“CPe1” the collapse potentials obtained from the void
ratio of the stress stage immediately before the inunda-
tion of the specimens.
Table 3. Collapsibility parameters from oedometric test in thin soils of the studied area
Samples w
(%)
wL
(%)
IP
(%)
S
(%) e0
d
(kN/m³) CC CV10-6
(m2/s)
CPe1
(%)
CPe0
(%)
P1A 5,8 31,4 11,2 16,6 0,96 13,92 0,38 5,62 0,22 0,21
P1B 10,4 36,0 15,9 27,1 1,06 13,37 0,47 5,44 2,04 2,00
P1C 8,2 37,0 16,0 22,8 0,98 13,88 0,45 5,08 0,72 0,69
P2A 5,5 30,0 10,6 15,5 0,97 14,01 0,39 4,43 1,83 1,75
P2B 6,4 32,7 13,2 17,3 1,02 13,58 0,44 4,31 2,85 2,73
P2C 5,9 35,5 11,9 15,5 1,04 13,50 0,50 2,87 5,73 5,52
P3A 5,8 30,0 12,3 17,0 0,93 13,97 0,37 7,14 7,27 7,19
P3B 5,0 28,7 10,1 13,6 1,00 13,56 0,36 9,50 9,68 9,28
P3C 4,3 28,0 9,2 11,2 1,07 13,51 0,34 3,06 3,45 3,26
P4A 5,9 29,0 9,3 18,1 0,90 14,40 0,37 4,41 2,34 2,22
P4B 8,5 32,3 13,1 22,5 1,03 13,45 0,41 4,74 2,12 2,02
P4C 5,9 32,0 11,0 16,4 1,00 13,84 0,40 4,36 1,10 1,04
P4D 11,7 43,5 14,2 35,8 0,90 14,57 0,36 3,79 1,76 1,69
P5A 8,7 30,7 12,9 22,4 1,06 13,23 0,35 2,35 3,21 2,93
P5B 7,6 31,0 13,3 26,1 0,81 15,22 0,34 4,45 3,97 3,79
P5C 7,6 32,7 12,3 21,2 0,99 13,78 0,34 3,44 6,80 6,58
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29
Nevertheless, it is understood that from the site of
analysed samples (P1, P2, P3, P4 and P5), considering the
samples obtained in at least one of the horizons during
the analysis (A, B, C or D), all present values of collapse
potentials indicate the presence of soils layers with high
collapsible potential in the aggregate soils of the studied
area. With the intention of discovering possible tenden-
cies of correlations between the obtained collapse poten-
tials and several physical indexes and parameters of cha-
racterization of the analyzed soils, investigations were
carried out using statistical correlations through the coef-
ficients of lineal correlation.
Mendonça et al. (1993) verified that the physical in-
dexes are the parameters that present the best lineal cor-
relation with the collapse potential; standing out among
them are the natural unit weight or natural dry unit
weight, the natural void ratio and the initial saturation of
degree, in decreasing order of correlation. In the present
paper, the parameters of the soils analyzed by statistical
correlations that obtained a larger lineal correlation front
to the values of the collapse potentials of the soils were,
in decreasing order: liquid limit “wL”, the soil natural
moisture “w”, plasticity index “IP”, saturation initial of
degree “S”, and for the dry unit weight “γd” and the
natural void ratio “e0”, low values of the coefficient of
lineal correlation front to the medium values of the col-
lapse potentials were verified.
In Figure 3 a surface graphic 3D of statistical repre-
sentation of the collapsibility data of analyzed samples is
shown. In agreement with the collapsibility approaches
of Clevenger (1956) and Holtz and Hilf (1961), soils
with dry unit weight smaller or equal to 12.82 kN/m³
present collapsible behavior. It is observed, in Figure 3,
that the soil samples considered as collapsible (letter “C”)
according to approach of Jennings and Knight (1975) pre-
sented values of dry unit weight above 12.82 kN/m³, and
the soil samples that were non collapsible (letter “N”)
presented values of dry unit weight between 13.37 and
14.57 kN/m³, indicating therefore that the approaches of
Clevenger (1956) and Holtz and Hilf (1961) are not ap-
propriate to analyze qualitatively the collapse potential of
the studied area soils.
Considering the adoption of the compressibility and/or
the collapsibility as an attribute that determines or inter-
feres in the behaviour of the aggregate soils, what hap-
pens to the compressibility of the aggregate soils before
the occurrence of the collapsibility phenomenon was co-
nsidered. This presents relatively smaller last values wh-
en compared with the abrupt reduction of volume due to
the collapse (Vargas, 1993). Therefore, an attribute that
interferes in the space analysis of the chart for shallow
foundations, related with possible problems of foundatio-
ns, in terms of specific deformations, is the collapsibility,
or better, the collapse potentials of the analyzed samples.
In the analysis and in the elaboration of the chart for
shallow foundations, a structural element of foundation
reference was adopted. A square shallow spot footing of
dimension B = 2.0 meters, supported at a depth of 1.50
meters below the surface of the land was used, and the
value of a representative medium NSPT of the support
layer, estimated at the depth of the stress bulb of the
shallow spot footing (~1.5B), was also considered. In
that way, NSPT used in the present paper was obtained
starting from the simple arithmetic average of NSPT found
in the layers located between the depth of the support of
the structural element of the foundation and the depth of
N
N
N
NNC
C
C
C
N
NN
N
C
C
C
Dry Unit Weight
(kN/m?
13,218
13,436
13,655
13,873
14,091
14,309
14,527
14,745
14,964
15,182
Figure 3. Surface graphic 3D to three parameters of collapsibility (Statistica/2000)
R. M. MENDES ET AL.
Copyright © 2010 SciRes JGIS
30
Figure 4. Chart of shallow foundation for residentials buildings ground floor (Mendes, 2001)
the stress bulb. Analyzing the Chart for Shallow Founda-
tions shown in Figure 4, 18.2% of the studied area be-
longs to the Restrictive class, 37.5% to the Severe class,
36.7% to the Moderate class and 7.6% to the Favourable
class.
5. Discussion and Conclusions
The classification of the studied area regarding suitability
conditions for the introduction of shallow foundations in
residential buildings concentrated among the Moderate
and Severe classes represented by 74.2% of the total area,
as a consequence of the prevalence of areas constituted
potentially by layers of collapsible soils, associated with
regions with low bearing capacity (generally presenting
value of NSPT < 6,0 blows/30cm), followed in decreasing
order of constituted regions by shallow water level and
high declivity.
For this reason, it is recommended not to adopt shal-
low foundations as an infrastructure solution in single
floor residential buildings placed mainly in regions clas-
sified as Severe or Restrictive, in agreement with the
adopted methodology; this type of foundation in the re-
gions classified as Favourable and also in the Moderate
class could be adopted, considering, however, some pro-
visos in the latter case.
A possible solution for the regions that presented un-
viable conditions in the adoption of shallow foundations
would be to adopt structural elements of a foundation
that would help to cross the most shallow layers of the
aggregate soils to a depth of approximately 6.0 meters
because, in that interval, the soil layers tend to present
serious problems related to collapse. For example, foun-
dations constituted by piling could be adopted.
6. Acknowledgements
The authors are grateful to the Municipal Town Hall of
São José do Rio Preto for the logistical support during
the period of sample collection and to the Statistics De-
partment of the Federal University of São Carlos (Brazil)
for use of the Statistica/99 Windows software.
REFERENCES
[1] Arid, F.M. (1966). The Bauru Formation in the western
region of the State of Sao Paulo. PhD thesis, Sao Paulo
State University, Brazil (in Portuguese).
[2] Augusto Filho, O., Ridente Jr., J.L., Alves, C.F.C. (1999)
Geotechnical compartment of the urban area of São José
do Rio Preto (Brazil) by spatial generalization of percus-
sion drilling data. Proceedings of the 9th Brazilian Con-
gress of Engineering Geology, Vol.1, pp. 1-14 (in Portu-
guese).
[3] Barcha, S. F. (1980). Geological and hydrogeological
R. M. MENDES ET AL.
Copyright © 2010 SciRes JGIS
31
aspects of the Bauru Formation in the western region of
the State of São Paulo. PhD thesis, São Paulo State Uni-
versity, Brazil (in Portuguese).
[4] Birkholz, L.B. et al. (1983) The urbanization process and
the development industrial in State of São Paulo. 2nd edi-
tion. Nobel, São Paulo (in Portuguese).
[5] Brasil–IBGE (2001) Statistical data of the censu popula-
tion of 2000, 1, 05-08 (http://www.ibge.gov.br
/ibge/estatistica/populacao/censo2000). (in Portuguese)
[6] Caiado, A.; Vasconcelos, L. (1994) The politics of attract
municipal: industrial location and industrial districts.
Mimeo, Campinas. (in Portuguese)
[7] Campolina Diniz, C.; Santos, F. (1995) South-west:
structural heterogeneous and perspectives. In: Affonso, R.
and Silva, P. (ed.), Federalism in Brazil. Regional ine-
qualities and development. São Paulo, pp 195-223 (in
Portuguese).
[8] Clevenger, W. A. (1956) Experiences with loess as foun-
dation material. Proceedings of the American Society of
Civil Engineers, 1025: pp. 1-26.
[9] Costa, T.C.D.; Gandolfi, N. (1998) The blue methylene
method and its correlation with the MCT classificacion.
Proceedings of the 8th Congress of the International As-
sociation for Engineering Geology and Environment, Vol.
1, pp. 307-314.
[10] Deutsch, C. V.; Journel, A.G. (1992) GSLIB: Geostatist-
ical Software Library and user's guide. Oxford University
Press, New York.
[11] Hang, P.T.; Brindley, G.W. (1970) Methylene blue ab-
sorption by clay minerals: determination of surface areas
and cation exchange capacities. Clays and Clay Minerals,
18, 203-212.
[12] Holtz, W.G.; Hilf, J.W. (1961) Settlement of soil founda-
tions due to saturation. Earth Dams Section. Bureau of
Reclamation, 673-679.
[13] Honorato, S.; Mackenna, J. (1975) Influence of the
grain-size distribution of an porous media on your per-
meability. Proceedings of the 5th Panamerican Congress
of Soil Mechanics and Foundation Engineering, Vol. 3,
pp. 135-148 (in Portuguese).
[14] Jennings, J.E.; Knight, K. (1975) A guide to construction
on or with materials exhibiting additional settlement due
to collapse of grain structure. Proceedings of the 6th Re-
gional Conference for Africa on Soil Mechanics and
Foundation Engineering, pp. 99-105.
[15] Lautrin, D. (1989) Utilisation pratique des paramètres
dèdivés de l’essai au bleu de méthylène dans les projets
de génie civil. Bull. Liaison Labo P. et Ch., 160, 53-65.
[16] Mendes, R.M. (2001) Geotechnical mapping of the urban
center area of São José do Rio Preto (Brazil) in scale
1:10.000 – as an aid to urban planning. M.S. thesis,
Federal University of São Carlos, São Paulo, Brazil (in
Portuguese).
[17] Mendonça, M.B; Mahler, C.F.; Pereira, J.H.F. (1993)
Laboratory tests on colapsible soils of the Bom Jesus da
Lapa (Brazil) region. Soils and Rocks, 16, 159-172 (in
Portuguese).
[18] Negri, B.; Pacheco, C. A. (1993) Technological change
and regional development in the 90’s: the internalization
of the development to new space dimension of the paulist
industry. Accord SCTDE/FECAMP/UNICAMP-IE (in
Portuguese).
[19] Nogami, J. S.; Villibor, D.F. (1979) Soil characterization
of mapping units for highway purposes in a tropical area.
Bulletin of the International Association of Engineering
Geology, 19, 196-199.
[20] Pejon, O. J. (1992) Geotechnical mapping of Piraci-
caba-Brazil (scale 1:100.000): study of methodology as-
pects, caracterization and attributes presentation. PhD
thesis, Engineering School of São Carlos, University of
São Paulo, Brazil (in Portuguese).
[21] São Paulo-FFLCH/USP-IPT-FAPESP (1997) Geomor-
phological map of the São Paulo State. In Ross, J.L.S.
and Moroz, I.C. (eds.), 64p + color map in scale
1:500.000 (in Portuguese).
[22] Statistica (2000) Statistica for windows: computer pro-
gram manual. StatSoft, Inc.,Tulsa, OK., one CDROM.
[23] Vargas, M. (1993) Colapsible and porous soils. Lecture
Notes. Engineering School of São Carlos, University of
São Paulo, Brazil (in Portuguese).
[24] Zuquette, L.V. (1987) Critical analysis of the geotechni-
cal mapping and methodological proposal for the brazil-
ian conditions. PhD thesis, Engineering School of São
Carlos, University of São Paulo, Brazil (in Portuguese).
[25] Zuquette, L.V. (1993) The importance of geotechnical
mapping in the use and occupation of the physical envi-
ronment: basis and guide for development. Free Acade-
mician thesis, Engineering School of São Carlos, Univer-
sity of São Paulo, Brazil (in Portuguese).