experimental study on the electrical resistivity of soil–cement admixtures
TRANSCRIPT
ORIGINAL PAPER
Experimental study on the electrical resistivityof soil–cement admixtures
Song Yu Liu Æ Yan Jun Du Æ L. H. Han ÆM. F. Gu
Received: 11 April 2007 / Accepted: 20 June 2007 / Published online: 20 July 2007
� Springer-Verlag 2007
Abstract Recently in China, soil–cement is widely used
to improve the soft ground in the highway construction
engineering. Literature studies are mainly investigating the
mechanical properties of the soil–cement, while its prop-
erties of the electrical resistivity are not well addressed. In
this paper, the properties of the electrical resistivity of the
reconstituted soil-cement and the in situ soil–cement col-
umns are investigated. The test results show that the
electrical resistivity of the soil–cement increases with the
increase in the cement-mixing ratio and curing time,
whereas it decreases with the increase in the water content,
degree of saturation and water–cement ratio. A simple
equation is proposed to predict the electrical resistivity of
soil–cement under the condition of the specified curing
time and water–cement ratio. It is found that the electrical
resistivity has a good relationship with the unconfined
compression strength and blow count of SPT. It is expected
that the electrical resistivity method can be widely used for
checking/controlling the quality of soil–cement in practice.
Keywords Soil–cement � Electrical resistivity �Unconfined compression strength � Test � Strength
prediction
Introduction
Recently in China, soil–cement is widely used for soft soil
improvement in highway construction. Currently, standard
penetration test (SPT) is the most popular method that is
used for checking the quality of soil–cement columns in
China (Liu and Hryciw 2003). Perhaps the serious disad-
vantage of this method is that it usually cause destruction
of soil–cement columns and may not be time and cost-
effective. Electrical resistivity method seems to be a rea-
sonable alternative which has advantage of non-destruction
and time-effective against SPT. For example, Seaton and
Burbey (2002) evaluated a fractured crystalline terrane
using the electrical resistivity method. Giao et al. (2003)
used the electrical resistivity for geotechnical investigation
of Pusan clay deposits. Miao et al. (2003) studied the
relationship between the electrical resistivity and the curing
time, the unconfined compression strength and the cement-
mixing ratio of laboratory prepared soil–cement admix-
tures. Miao et al. (2003) discussed the possibility of
applying the electrical resistivity method for checking the
quality of deep mixed cement columns. However, none of
these literature studies systematically investigate the fac-
tors affecting the electrical resistivity of soil–cement
admixtures or propose a simple method to predict the
electrical resistivity of soil–cement admixtures under the
specified condition.
The purpose of this paper is to investigate the factors
that control the characteristics of the electrical resistivity of
soil–cement admixtures. For this purpose, a series of lab-
oratory tests and field in-situ tests have been carried out for
the cement stabilized typical marine soft soil located at
LianYunGang City, China. The effects of cement-mixing
ratio (hereinafter labelled Aw), water content, degree of
saturation, water–cement ratio (hereinafter labelled w/c)
and curing time on the electrical resistivity of soil–cement
admixtures are discussed. A simple equation is proposed to
predict the electrical resistivity of soil–cement admixtures.
Finally, the electrical resistivity method is used to predict
S. Y. Liu � Y. J. Du (&) � L. H. Han � M. F. Gu
Institute of Geotechnical Engineering,
Southeast University, Nanjing 210096, Jiangsu, China
e-mail: [email protected]
123
Environ Geol (2008) 54:1227–1233
DOI 10.1007/s00254-007-0905-5
and compare with the measured unconfined compression
strength of soil–cement columns installed in the Lian-
YunGang-Nanjing Highway section.
Materials and test methods
The clays used in this study were sampled from the marine
deposits located in the Lian YunGang city, Jiangsu prov-
ince, China. The main physical properties of the clay are
summarized in Table 1. Disturbed soils were sampled at
depths of 2–3, 4–5 and 8–9 m (Fig. 1).
In this study, the electrical resistivity of the soil–cement
was measured using the two-electrode probe method and a
test apparatus developed by the Institute of Geotechnical
Engineering, Southeast University (Yu 2004). The details
of the test apparatus were discussed by Yu (2004). The
electric frequency of the test apparatus was set as 50 Hz,
which is consistent with that used in the daily life of China.
The reliability of the test apparatus was discussed by Yu
(2004) by comparing the measured electrical resistivity of
soil–cement admixtures with the measured values using the
ASTM G187-05 standard test method. The schematic of
this test method is shown in Fig. 1, in which the electrical
resistivity of the soil–cement admixture, q (Wm), is cal-
culated based on the following equation:
q ¼ DU
I
A
Lð1Þ
in which DU = the electrical voltage applied to the soil
(volts), I = the electrical current (amps) A = the cross-
section area (m2) through which electrical current con-
ducts, and L = the length of the soil-cement admixture
specimen (meter) parallel to the electrical current.
In this study, the copper electrode probe was used with a
length of 70 mm, width of 70 mm and thickness of 2 mm.
The probes were placed on the top and at the bottom of the
soil–cement specimens during the measurement of the
electrical resistivity. The ordinary Portland cement (Type
I) was used as the binder to stabilize the soft soils. The
soil–cement sample was prepared in a cubic box with the
size of 70.7 mm, width of 70.7 mm and thickness of
70.7 mm. In this study the cement mixing ratio is defined
as Aw = wc/ws, where wc = the weight of dry cement,
ws = the weight of the soil with natural water content; the
water–cement ratio presented in this study is defined as
w/c = ww/wc, where ww = the weight of the total water in
the soil–water–cement mixture consisting of water initially
contained in the soil and water added to hydrate the cement
(Lorenzo and Bergado 2004). To investigate the effect of
cement-mixing ratio on the properties of the electrical
resistivity, Aw was set as 8, 10, 12 and 15% corresponding
to w/c of 4.7, 3.8, 3.1 and 2.7%. To investigate the effect of
degree of saturation on the electrical resistivity of soil–
cement, Aw was set as 8% and w/c was set in a range of
1–6%. Three parallel soil–cement admixture specimens
were prepared except for the case of Aw = 12%,
wc = 3.1%, and curing time of 20 days in which only two
parallel specimens were prepared. The soil–cement sam-
ples were cured under the controlled condition with a
Table 1 Geotechnical engineering properties of the LianYunGang
soft soil
Properties Characteristic
values
Specific gravity, Gs 2.68
Liquid limit, wL (%) 63
Plastic limit, wP (%) 25
Natural water content, wn (%) 39
Grain size distribution (%)
Clay (<2 lm) 65
Silt 23
Sand 12
I
V
Soil sample
Electrical source
∆U
I
Soil sample
Electrical source
∆U
Fig. 1 Schematic of the two electrode probe method
7 9 10 11 12 13 14 150
1
2
3
4
5
6
7
16
w/c =2.5
w/c =3.1
w/c =3.8
w/c =4.7
Ele
ctri
cal r
esis
tivity
, ρ (
ohm
-m)
Cement mixing ratio, Aw (%)
Curing time is 7days Curing time is 20 days Curing time is 34 days Trend line
8
Fig. 2 Relationship between the electrical resistivity and cement
mixing ratio of soil–cement admixtures
1228 Environ Geol (2008) 54:1227–1233
123
temperature of 20 ± 3�C and the relative humidity of 100%
for 10, 20, and 34 days to investigate the effect of curing
time on the electrical resistivity of the soil–cement
admixtures. All of the measurements of the electrical
resistivity were performed under the controlled tempera-
ture of 20 ± 3�C.
For the investigation of the effect of Aw, w/c, degree of
saturation and curing time on the electrical resistivity of
soil–cement admixtures, a vertical pressure of 20 kPa was
applied on the copper probes to make a well contact con-
dition between the probes and specimens. This pressure
was found to have little effect on the shear strength of the
soil–cement admixture samples.
Results and discussion
Effect of Aw on electrical resistivity
The relationship between the measured electrical resistivity
and Aw of the soil–cement admixture is plotted in Fig. 2. It
is found that the electrical resistivity increased with the
increase in Aw. Komine (1997) proposed a model for the
electrical resistivity of the soil–cement admixture and
which consists of three parts: electrical resistivity of soil,
electrical resistivity of cement and electrical resistivity of
pore water. He indicated that among these three factors, the
effect of pore water on the electrical resistivity was most
significant due to its highest electrical conductance (the
inverse of the electrical resistance). With the increase in
Aw, water content and void ratio of the soil–cement
admixture decreased due to the hydration reaction and
pozzolanic reaction. Therefore, the conduction path for the
electrical current became more tortuous. As a result, the
electrical resistivity of the soil–cement admixture
increased.
Effect of degree of saturation on electrical resistivity
McNeill (1999) proposed an empirical equation describing
the relationship between the electrical resistivity of satu-
rated soils and unsaturated soils as expressed:
q ¼ qsat Sr=100ð Þ�B ð2Þ
where q = the electrical resistivity of unsaturated soils
(Wm), qsat = the electrical resistivity of saturated soils
(Wm), Sr = the degree of saturation (%), and B = the
empirical constant depending on the soil type. In this study,
an attempt was made to apply Eq. (2) for the soil–cement
admixtures under the conditions presented in this study.
The relationship between the measured electrical resistivity
(q) and the measured value of Sr of soil–cement admixture
is shown in Fig. 3. The values of B and qsat were derived as
3.46 and 1.23, respectively by fitting Eq. (2) to the mea-
sured electrical resistivity (q) of soil–cement admixtures. It
is found that electrical resistivity (q) increased with the
decrease in degree of saturation. The reason for this
observation is mainly because with the decrease in the
degree of saturation, less pore spaces were filled with pore
water and thereby the path for the electrical current became
less tortuous in the soil–cement. As a result, the electrical
resistivity increased.
Effect of w/c on electrical resistivity
The relationship between the electrical resistivity and w/c
of the soil–cement admixtures is plotted in Fig. 4. With the
decrease in w/c, the electrical resistivity increased. The
reason is mainly because that with the decrease in w/c, Aw
increased (see Fig. 4) which leads to the decrease in the
void ratio and water content of the soil–cement. The con-
duction path for the electrical current became more tortu-
ous. Thereby, the electrical resistivity of soil–cement
admixture increased. This observation is consistent with
the literature (Horpibulsuk et al. 2003) in that w/c was one
of the important factors controlling the geotechnical
behavior of the soil–cement admixtures.
Effect of curing time on electrical resistivity
The relationship between the curing time and the measured
electrical resistivity of soil–cement is shown in Fig. 5. It
can be seen that with the increase in the curing time, the
electrical resistivity of soil–cement increased. The main
reason is that with the increase in the curing time, the
pozzolanic reaction was enhanced so that water content of
55 60 65 70 75 80 85 90 95 1000
1
2
3
4
5
6
7
Fitted line by Eq. (2) ρ = 1.23(S
r/100)-3.46
r2 = 0.97
Ele
ctri
cal r
esis
tivity
, (
ohm
-m)
Degree of saturation, Sr (%)
Aw= 8% w/c = 1 - 6%
Curing time = 7 - 35 days
ρ
Fig. 3 Relationship between electrical resistivity and degree of
saturation of soil–cement admixtures
Environ Geol (2008) 54:1227–1233 1229
123
soil–cement admixture decreased (Horpibulsuk et al.
2003). Furthermore, with the increase in the curing time,
contents of chemical reaction productions such as calcium
silicate hydrate (CSH) and calcium aluminate hydrate
(CAH) formed so that more fine soil particles are bonded
together resulting in a denser soil structure (Bergado et al.
1996; Holm 1999). These two aspects lead to more tortuous
pathways for the flow of electrical current in the soil–ce-
ment mixture. Therefore, the electrical resistivity of the
soil–cement increased.
Proposed equation to predict electrical resistivity
Yu (2004) found that the electrical resistivity of soil–ce-
ment mixture has a good relationship with w/c and curing
time, and indicated that the electrical resistivity was the
power function of w/c and exponential function of curing
time. However, Yu (2004) separately discussed the rela-
tionship between the electrical resistivity and w/c, and did
not combine these two factors in one simple equation,
which makes it difficult to be applied in practice. In this
study, it is assumed that the relationship between the
electrical resistivity and w/c and curing time can be ex-
pressed by:
qðw=cÞDqðw=cÞ34
¼ A ðw=cÞ34ð Þ� ðw=cÞDð Þf g Bþ C ln Dð Þ ð3Þ
in which q(w/c)D = the electrical resistivity at curing time of
D day(Wm), q(w/c)34 = the electrical resistivity at curing
time of 34 days (Wm), (w/c)D = the water–cement ratio of
D days, (w/c)34 = the water–cement ratio at the curing time
of 34 days, D = curing time (day), and A, B, C = constants.
Based on the electrical resistivity and w/c at curing time
of 7, 20, 34 days shown in Fig. 5, the values of A, B and C
were back-calculated as A = 1.35, B = 0.042 and C = 0.22.
Therefore, Eq. (3) can be expressed by
qðw=cÞDqðw=cÞ34
¼ 1:35 ðw=cÞ34ð Þ� ðw=cÞDð Þf g 0:042þ 0:22 ln Dð Þ ð4Þ
The predicted electrical resistivity (qp) of soil–cement at
the curing time of 7, 20 and 34 days using Eq. (4) are
plotted in Fig. 6 versus the measured values (qm). In this
study, the measured values of the electrical resistivity at the
curing time of 34 days, 2.58(Wm) and the corresponding
w/c, 4.69, were used as the value of q(w/c)34 in Eq. (4) for
the prediction. From Fig. 6, it can be seen that most of the
predicted values are well consistent with the measured
ones, indicating that the proposed Equation is reasonable.
The predicted values mainly distributes in the region of
2 3 4 50
1
2
3
4
5
6
7
Aw = 15%
Aw = 12%
Aw = 10% A
w = 8%
Ele
ctri
cal r
esis
tivity
, ρ (
ohm
-m)
Water-cement ratio, w/c (%)
Curing time is 7days Curing time is 20 days Curing time is 34 days Trend line
Fig. 4 Effect of water–cement ratio on electrical resistivity of soil–
cement admixtures
0 10 15 20 25 30 35 400
1
2
3
4
5
6
7
Trend line
Ele
ctri
cal r
esis
tivity
, ρ (
ohm
-m)
Curing time, D (day)
Aw= 8%,w/c = 4.7
Aw= 10%,w/c = 3.8
Aw= 12%,w/c = 3.1
Aw= 15%,w/c = 2.5
Trend line
5
Fig. 5 Relationship between electrical resistivity and curing time of
soil–cement admixtures
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.00.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
ρp = 0.75ρ
m
ρp = ρ
m- 1.0
ρp = ρ
m- 2.0
ρp = ρ
m
Curing time D = 7 daysCuring time D = 20 daysCuring time D = 34 days
Pred
icte
d el
ectr
ical
res
istiv
ity, ρ
p(ohm
-m)
Measured electrical resistivity, ρm (ohm-m)
Fig. 6 Comparison between measured and predicted electrical
resistivity of soil–cement admixtures
1230 Environ Geol (2008) 54:1227–1233
123
qp = qm to qp = qm-1.0 when qm is less than 4.5 Wm, while
they distributes mainly in the region of qp = qm – 1.0 to
qp = qm – 2.0 when qm is higher than 4.5 Wm. Generally,
the predicted values are about 25% lower than the mea-
sured values (Fig. 6). The possible reasons for this obser-
vation may be due to the limited measured data present in
Fig. 5, which might have resulted in slight error when the
parameters A, B, and C in Eq. 5 were back-calculated by
fitting. Although there is such a limitation, the method for
predicting electrical resistivity of soil–cement admixture
presented in this study is interesting for discussion and for
practical application. A benefit to use this proposed equa-
tion is that it is convenient to predict the electrical resis-
tivity of soil–cement admixture under the condition of the
specified w/c and curing time given that the electrical
resistivity and w/c at the curing time of 34 days are
measured. It is noted that although in most practice that the
curing time at 28 days for soil–cement admixture is
concerned, the curing time at 34 days presented in this
study is useful to discuss the proposal of a simple equation
to predict the electrical resistivity of soil–cement admix-
ture.
Relationship between the unconfined compression
strength and electrical resistivity
Since the electrical resistivity of the soil–cement is affected
by Aw, w/c and curing time which also affect the uncon-
fined compressive strength of the cement stabilized soil
(Horpibulsuk et al. 2003), it is thought that there would be
a relationship between the electrical resistivity and the
unconfined compressive strength. For this consideration,
the measured electrical resistivity (q) versus unconfined
compressive strength (qu) of the laboratory prepared soil–
cement admixtures is plotted in Fig. 7. It can be seen that
with the increase in the unconfined compressive strength
the electrical resistivity is increased. An empirical equation
is derived from Fig. 7:
qu ¼ 286q� 334 R2 ¼ 0:89 ð5Þ
Using Eq (5), one can easily predict the unconfined com-
pressive strength of soil-cement and consequently deter-
mine the bearing capacity of the soil–cement column
installed in the field.
The relationship between unconfined compressive
strength and electrical resistivity of soil–cement columns is
also examined by the field test of soil–cement columns
installed in the LianYunGang section of Lian-Xu Highway
for improvement of LianYunGang soft soil. A detailed
description of the soil properties and embankment settle-
ment in this area is given by Chai et al. (2002). The cement
columns were installed by dry-jet mixed method. The
cement columns have properties of Aw = 11%, w/c = 2.5
and curing time = 28 days. The SPT test was performed
for the cement column in the field. The unconfined com-
pressive strength and the electrical resistivity were mea-
sured on the boring samples of cement columns in the
laboratory. The variation of typical SPT N value and
unconfined compressive strength with the installation depth
of cement column is shown in Fig. 8. It can be seen that
both SPT N and qu varied with the depth of cement column.
This may be mainly due to that the cement was not hom-
ogenously injected during the installation of the cement
column.
The relationships between the electrical resistivity and
SPT N value and unconfined compressive strength are
0 1 2 3 4 5 6 70
200
400
600
800
1000
1200
1400
1600
1800
Unc
onfi
ned
com
pres
sive
str
engt
h, q
u(kPa
)
Electrical resistivity, ρ (ohm-m)
Curing time = 7 days Curing time = 20 days Curing time = 34 days
Aw = 8% - 15%, w/c = 2.5 - 4.7%
qu = 286ρ - 334
R2= 0.89
Fig. 7 Relationship between the electrical resistivity and the
unconfined compression strength of soil–cement admixtures
12
11
10
9
8
7
6
5
4
3
2
1
01 10 100 1000
Aw= 11%, w/c = 2.5
Curing time = 28 days
Electrical resistivity Blow count of SPT Unconfined compressive strength
Dep
th (
m)
Unconfined compressive strength qu(kPa)
1 10 100 1000
Electrical resistivity (ohm-m), SPT (N)
Fig. 8 Distribution of measured electrical resistivity, blow count of
SPT, and unconfined compressive strength along depth for cement
columns installed in Lian-Yu highway
Environ Geol (2008) 54:1227–1233 1231
123
shown in Figs. 9, and 10, respectively. Unlike Fig. 7,
Figs. 8, 9 show that when the electrical resistivity is less
than about 2.7 Wm, the values of SPT N and qu practically
remain constant. The reason that why at this range of low
electrical resistivity (i.e., <2.7 Wm) is not clear. However,
when the electrical resistivity is higher than 2.7 Wm, the
values of SPT N and qu increased with the increase in the
electrical resistivity. The relationships between the elec-
trical resistivity and SPT N and qu in the case that the
electrical resistivity is higher than 2.7 Wm can be ex-
pressed by the following equations:
N ¼ 2:3qþ 2:7 R2 ¼ 0:81� �
ð6Þ
qu ¼ 99q� 292 R2 ¼ 0:81� �
ð7Þ
In Fig. 10, the predicted unconfined compressive strength
using Eq. 5 are also plotted. However, the predicted values
using Eq. 5 are higher than the measured values and pre-
dicted values using Eq. 7. This may be mainly due to the
difference in the soil nature, Aw, w/c, and curing time be-
tween the laboratory test condition and the field test con-
dition. Therefore, the predicted values calculated by Eq. 5,
which represents the laboratory test condition, are different
from the predicted values calculated by Eq. 7, which rep-
resents the field test condition (Fig. 10).
Practical implication
Equations (5–7) indicate that for the cement stabilized
LianYunGang soft soils and dry-jet-mixed cement columns
installed in the Lian-Yu highway, there is a good rela-
tionship between the electrical resistivity and shear
strengths. Therefore, it is expected that this method can be
used as a non-destructive and both time and cost-effective
way to evaluate the quality of the dry-jet-mixed cement
columns in practice.
Conclusions
This paper presents the laboratory test results for investi-
gating the factors controlling the electrical resistivity of
soil-cement admixture. A simple equation is proposed to
predict the electrical resistivity under specific water-ce-
ment ratio and curing time. The relationship between the
measured electrical resistivity and unconfined compressive
strength of the soil–cement admixture is discussed. The
relationship between the measured electrical resistivity and
SPT N value and unconfined compressive strength of dry-
jet mixed cement column installed in the Lian-Xu Highway
is assessed. Following conclusions can be obtained from
this study:
The electrical resistivity of the soil–cement admixture
increased with the increase in the cement mixing ratio and
curing time, while decreased with the increase in the de-
gree of saturation and water–cement ratio.
Combining the effect of water–cement ratio and curing
time, based on the measured electrical resistivity at the
curing time of 34 days, a simple empirical equation is
proposed to predict the electrical resistivity of the soil–
cement admixture under the condition of the specified
water–cement ratio and curing time.
The laboratory test shows that the electrical resistivity of
the soil–cement admixture prepared in the laboratory has a
good relationship with the unconfined compressive
strength. The field tests indicate that at the relatively higher
electrical resistivity, the measured electrical resistivity has
0 1 2 3 4 5 6 7 8 9 100
2
4
6
8
10
12
14
16
18
20
22
24
26
28
Blo
w c
ount
of
SPT
(N
)
Electrical resistivity, ρ (ohm-m)
N = 2.3ρ +2.7
R2= 0.82
Fig. 9 Relationship between the electrical resistivity and SPT N
value of cement columns installed in Lian-Xu highway
0 1 2 3 4 5 6 7 8 9 100
100
200
300
400
500
600
700
800
qu = 286ρ - 334, Eq. 5
Unc
onfi
ned
com
pres
sive
str
engt
h, q
u(kPa
)
Electrical resistivity, ρ (ohm-m)
qu = 99ρ - 282
R2= 0.81
Fig. 10 Relationship between the electrical resistivity and uncon-
fined compressive strength of cement columns installed in Lian-Xu
highway
1232 Environ Geol (2008) 54:1227–1233
123
a good relationship with SPT N value and unconfined
compressive strength of the cement column installed in the
Lian-Xu Highway. An implication to practice is that the
electrical resistivity method can be used as a non-destruc-
tive and time and cost-effective to evaluate and control the
quality of dry-jet-mixed cement columns.
Ackowledgment This study is part of the Project titled ‘‘On the
electrical resistivity characteristics of structural Soils’’ financially
supported by the Natural Science Foundation of China (NSFC) (Grant
No. 50478073,2005–2007). The authors highly appreciate Dr. A.
Sridharan, Professor Emeritus, Indian Institute of Science, for his
comments and discussions during the preparation of this paper.
References
ASTM (2005) Standard test method for measurement of soil
resistivity using the two-electrode soil box method (G187–05).
American Society for Testing and Materials
Bergado DT, Anderson LR, Miura N, Balasubramaniam AS (1996)
Soft ground improvement in lowland and other environments.
American Society of Civil Engineers, New York
Chai JC, Liu SY, Du YJ (2002) Field properties and settlement
calculation of soil-cement column improved soft subsoil-a case
study. Lowland Technol Int 4(2):51–58
Giao PH, Chung SG, Kim DY, Tanaka H (2003) Electric imaging and
laboratory resistivity testing for geotechnical investigation of
Pusan clay deposits. J Appl Geophys 52(4):157–175
Holm G (1999) Applications of dry mix methods for deep soil
stabilization. Paper presented at the international conference on
dry mix methods for deep soil stabilization, Stockholm, pp 3–13
Horpibulsuk S, Miura N, Nagaraj TS (2003) Assessment of strength
development in cement admixed high water content clays with
Abram’s law as a basis. Geotechnique 53(4):439–444
Komine H (1997) Evaluation of chemical grouted soil by electrical
resistivity. Ground Improvement 1:101–113
Lorenzo GA, Bergado DT (2004) Fundamental parameters of cement-
admixed clay-new approach. J Geotech Geoenviron Eng ASCE
130(10):1042–1050
Liu SY, Hryciw RD (2003) Evaluation and quality control of dry-jet-
mixed clay soil–cement columns by standard penetration test.
J Transportation Res Board 1849:47–52
McNeill J (1999) Use of electromagnetic methods for groundwater
studies. In: Ward SH (ed) Geotechnical and environmental
geophysics. Society Of Exploration Geophysicists, pp 191–218
Miao LC, Liu SY, Yan ML (2003) Research on electrical resistivity
feature of soil–cement and its application. Rock Soil Mech
20(1):126–130
Seaton WJ, Burbey TJ (2002) Evaluation of two-dimensional
resistivity methods in a fractured crystalline-rock terrane. J
Appl Geophys 51(1):21–41
Yu XJ (2004) On the theory and application of electrical resistivity
method in geotechnial engineering (in Chinese). PhD, Southeast
University, Nanjing, China
Environ Geol (2008) 54:1227–1233 1233
123