Reports on Geodesy and Geoinformatics, 2023, Vol. 116, pp.

69–76

DOI: 10.2478/rgg-2023-0012
Received: 15 September 2023 / Accepted: 12 December 2023
Published online: 29 December 2023

ORIGINAL ARTICLE

Solution of inclinometer data processing for horizontal

displacement: A case study of basement diaphragm wall
monitoring in Vietnam
Tran Dinh Trong 1 , Luong Ngoc Dung 1* and Vu Ngoc Quang 2

1
Department of Geodesy and Geomatics Engineering, Hanoi University of Civil Engineering, 55 Giai Phong Road,
10000, Hanoi, Vietnam
2
Department of Planning and Urban Transport, University of Transport Technology, 54 Trieu Khuc Road, 10000,
Hanoi, Vietnam
* dungln@huce.edu.vn

Abstract

In the recent decade, Digitilt DataMate II and GK-604D inclinometer systems have commonly been used to evaluate horizontal
displacement as well as to test the calculation models of basement diaphragm walls in Vietnam. The difference in the equipment
constants as well as the calculation principle has confused the surveyors and even led to erroneous monitoring results.
Furthermore, the use of commercial programs DigiPro2 and SiteMater, which are expensive, in inclinometer data processing
requires a thorough understanding. Differences in calculation results between software occur due to the choice of the instrument
constant, the rounding principle, or the choice of the reference point at the bottom of the monitoring pipe. In this paper, we
summarize the calculation principles of Digitilt DataMate II and GK-604D inclinometer systems. To respond well to the data
processing of inclinometer systems for basement diaphragm walls in Vietnam, we have developed the ICTool program that can
efficiently calculate the observed data of the GK-604D system. The results of inclinometer data processing by the ICTool program
are homogeneous in comparison with DigiPro2 and SiteMater software. In addition, the ICTool program was established to
provide, free of charge, the communication of the monitoring of basement diaphragm wall displacement in Vietnam.

Key words: inclinometer data processing, DataMate II, GK-604D, basement diaphragm wall, inclinometer instrument constants

1 Introduction When processing inclinometer calculation data, there are many

factors to keep in mind, such as instrument constant, rotation cor-
In the world, inclinometer systems are often used for the assess- rection, and reference point correction. Notes have been made
ment of landslides and basement diaphragm wall monitoring (Allil regarding rotation correction (ASTM D6230-13, 2013; Mikkelsen,
et al., 2021; Grodecki et al., 2018; Nguyen and Luu, 2013; Arroyo et al., 2003) or the movement reference points (usually the inclinome-
2008; Stark and Choi, 2008; Teparaksa and Teparaksa, 2019; Zhang ter toe) for calculating wall deflections (ASTM D6230-13, 2013;
et al., 2018). In the recent decade in Vietnam, inclinometer systems Grodecki et al., 2018; Hsiung and Hwang, 2009; Hwang and Wong,
have also been applied to analyze horizontal displacement and test 2018; Liu et al., 2011; Pham et al., 2021), but instrument constants
the diaphragm walls model during the construction of basement are not mentioned. In the study of the error sources of the incli-
excavation (Nguyen and Luu, 2013; Van Tram et al., 2014). It can be nometer system (Mikkelsen, 2003), Mikkelsen showed the instru-
seen that the correct calculation of inclinometer monitoring data is ment constant as 25000 (Metric probe) or 20000 (English probe).
necessary. The specification (ASTM D6230-13, 2013) states that the calcula-

This work is available in Open Access model and licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.
Publisher: De Gruyter

69
 70 | Reports on Geodesy and Geoinformatics, 2023, Vol. 116, pp. 69–76

tion depends on the device constant K, which is provided by the

manufacturer.
In Vietnam, the commonly used inclinometer systems are Digi-
tilt DataMate II and GK-604D. These systems have different instru-
ment constants. Specifically, the DataMate II instrument (Slope
Indicator, 2014) has a factor of 20000 for the English unit and 25000
for the metric unit. Meanwhile, the instrument constant value of
the GK-604D Inclinometer is always 20000 (Deep Excavation, 2021).
SiteMaster and DigiPro2 (Deep Excavation, 2023; Slope Indicator,
2013) are the respective commercial software to make suitable cal-
culations for the GK-604D and Digitilt DataMate II monitoring
systems. When using a software to calculate the observed data from
the another manufacturer, it is necessary to choose the suitable in-
strument constant following the calculation principle. For example,
when processing GK-604D data using Geoslope’s DigiPro2 soft-
ware, without any notes from the manufacturers, an instrument
Figure 1. Conventional directions A and B in monitoring Horizontal dis-
constant of 40000 was selected to obtain the correct displacement
placement inclinometer
value according to the calculation principle of Geokon manufacturer.
These confusions in the inclinometer data processing have put the
Vietnamese surveyors in an embarrassing situation and there is
even a possibility that readings are interpreted incorrectly resulting
in misleading wall deflections (Moffat et al., 2019).
The paper Dung et al. (2020) presents a study on recommenda-
tions for collecting and processing inclinometer data for basement
diaphragm walls in Vietnam. In this paper, we clarify the calcula-
tion principles for the Digitilt DataMate II and GK-604D devices;
the ICTool program was developed to contribute to the GK-604D
data processing. Raw data for 9 cycles of an inclinometer belonging
to the project at 165 Xa Dan, Hanoi, were used to test the ICTool
program in comparison with commercial software DigiPro2 and
SiteMaster 2012. The ICTool program is a freely accessible tool that
we have developed and generously shared on The Open Science
Framework (OSF) website (ICTool, 2023). This program stands as a
cost-effective solution to benefit users globally, particularly those
who may lack access to costly commercial software. Additionally, it
also serves as a valuable alternative for researchers working with in-
clinometer data, eliminating the need for investment in expensive
commercial software. In this regard, the results of this study are of Figure 2. The values of deviation (a) and cumulative deviation (b) (Slope
interest to the structural health monitoring community as well as Indicator, 2011)
many surveying engineering applications. In addition, they can be
instructive from an educational point of view, as well as beneficial
to the on-site implementation. The cumulative deviation (d) of each axis of the casing is the
sum of the lateral deviations (di ) calculated from the bottom of the
casing, Figure 2 (b), shown in Eq. (2).
2 Methodology

2.1 General principle of inclinometer monitoring d = d1 + d2 + d3 + · · · + dn (2)

Inclinometer monitoring is based on the operating principle of the In which: d is the cumulative deviation from the bottom of the
accelerometer sensors located at the probe. When measuring hor- casing, and di is the deviation of each measurement interval.
izontal displacement, the probe has a system of two wheels run- The cumulative deviations of the casing compared to the vertical
ning along the grooves in the casing. The probe consists of two are used to determine the horizontal displacement value along the
force-balanced accelerometers: an accelerometer that measures depth of the observed object.
inclination in the plane of the probe wheels, which is called the A DigiPro2 and SiteMaster software are calculation tools provided
axis (commonly referred to as the direction of pressure); the other for data processing of Digitilt DataMate II and GK-604D instru-
accelerometer measures the inclination in the plane perpendicular ments respectively. The principles of these calculation are detailed
to the plane of the wheels, this plane is called the B-axis, Figure 1. in the following paragraphs.
In Figure 2 (a), the deviation (di ) at each monitoring position
of the casing is the relationship between the angle of inclination
(θi – determined by the accelerometer) and the reading interval 2.2 Calculation principle of Digipro2 software
(L) calculated by Eq. (1).
The readings displayed on the Digitilt DataMate II and imported
into Digipro2 software are not the angle or deviation of the casing,
di = L sin θi (1) Figure 3. These results are proportional to the tilt angle of the casing
and the instrument constant, which is represented by the following
In which: di is the deviation, L is the measurement interval (usually Eq. (3).
0.5 m or 2 feet), θi is the angle of tilt compared to the vertical at the
ith measurement point.
 Dinh Trong et al, 2023 | 71

Figure 4. Raw data obtained from GeoKon GK-604D device (Deep Exca-
vation, 2021)
Figure 3. Observed data displayed in Digipro2 software

inclination, and it is related to the horizontal deviation value shown

in Eqs. (6, 7, 8).

Di = IC sin θi (3)
SA = (A+) – (A–) /2
 
(6)
SB = (B+) – (B–) /2
 
In which: Di is the lateral deviation, and IC is the instrument con-
stant.
In which: A+, B+ are readings of A0 and B0 directions; A–, B– are
In a two-way measurement, the result of lateral deviation is
readings of A180 and B180 directions; SA , SB are the average values
the average value of two reversal measurements, Eq. (4). The first
of readings in two-way 0 and 180.
measurement has a conventional 0◦ direction and the second one
is 180◦ when the probe is reversed. This two-way measurement
allows the detection of systematic errors through check-sum value, CA = SA · M · RINT
which is the algebraic sum of the measured values in the two di- (7)
CB = SB · M · RINT
rections 0◦ and 180◦ for each reading interva; this value should
theoretically be zero. In which: M is the constant, equal to 0.05 corresponding to the
deviation value in millimeters and equal to 0.005 in centimeters;
RINT is the reading interval, this value is always 0.5 m; CA and CB
Di = (A0 – A180 ) /2 (4) are the values of local lateral deviation, regardless of directional
angle.
In which: A0 is observed data in the 0◦ direction of axis A, and A180
is observed data in the 180◦ direction of axis A.
In two readings, we always have direction A0 and A180 readings DA = CA cos ZZ – CB sin ZZ
(8)
with opposite signs. Thus, the relationship between Eq. (1) and DB = CA sin ZZ + CB cos ZZ
the observed data shown in Eqs. (3, 4) give us the value of the
horizontal deviation in the depth of the casing in each interval, In which: ZZ is the directional angle; DA and DB are the horizontal
which is represented by Eq. (5). deviation values considering the directional angle.
In Figure 4 we can see an example of the raw observed data of a
GK-604D inclinometer up to a depth of 30 m.
D
 
di = L sin θi = L = L (A0 – A180 ) / (2IC) (5) With readings at a depth of 30 m that is noted in the red rectangle,
IC
we have readings of direction A+ = 1013, B+ = –380, and direction
A– = –1052, B– = 320. The rounding calculation using Eq. (6),
For example, to calculate the red oval in Figure 3 with observed
SA = 1033, SB = –350, continuing to apply Eq. (7) to calculate the
data at a depth of 3.5 m, and according to the calculation instructions
horizontal deviation value at this position in centimeters, regardless
of the Digitilt DataMate II device (Slope Indicator, 2011), with the
of the directional angle ZZ, we have CA = 1033 · 0.005 · 0.5 = 2.58
device constant IC = 25000 (in metric units) and the probe length
cm, CB = –350 · 0.005 · 0.5 = –0.88 cm. The result of the A direction
L = 500 mm, we can calculate the lateral deviation of the A axis
is illustrated in the red rectangle of Figure 5, the B direction result
with reading A0 = –299 and A180 = 154 which is di = –4.53 mm in
is not shown here.
applying Eq. (5).
When observing a local object, regardless of the spatial orienta-
The horizontal displacement value is calculated by subtracting
tion angle, we can assume that pressure is directed perpendicular
the initial lateral deviation from the current deviation. Since this
to the diaphragm wall, so the directional angle is ZZ = 0◦ . Then
value is the horizontal movement of the casing, this value is also
we can see that the value of DA , DB in formula (8) equals the value
the horizontal displacement of the observed object.
CA , CB . In Vietnam, displacement monitoring is mostly applied
to observe the diaphragm wall in the basement. This is a locally
2.3 Calculation principle of SiteMaster software observed object and therefore, during monitoring, it is always put
the ZZ value to zero. Thus we can easily identify the displacement
The probe of GK-604D, including two Micro-Electro-Mechanical of the diaphragm wall following the direction of the excavation. In
Sensor accelerometers, directly gives A+, and A- readings at each this case, applying formulas (7) and (8) provides the same results.
monitor depth when the wheels of the probe run in the groove of Similar to calculating with data at the depth of 29.5 m, we get the
plane A. At the same time, the remaining accelerometer gives us the value of the A-axis deviation of CA = 2.41 cm. In conformity with the
interpolation reading B+, B- of the B axis, Figure 1. These readings principle of horizontal displacement calculated from the bottom of
are the output voltage which is proportional to the sine of the angle the monitoring pipe, we have the horizontal displacement value at
 72 | Reports on Geodesy and Geoinformatics, 2023, Vol. 116, pp. 69–76

Figure 5. Area of monitoring and surveillance Value of A-axis lateral

deviation (Deep Excavation, 2021)

29.5m depth which is 4.99 cm, equal to the cumulative displacement

from 30 m to 29.5 m, shown in the red rectangle of Figure 5.
Although still complying with the general principle, there are
still differences that need attention in calculating the horizontal dis-
placement, Digipro2 and SiteMaster software, corresponding to the
Digitilt DataMateII and GK-604D instruments. Firstly, the notation
convention for the monitoring axes is "0" and "180" or "+" and
"-". Secondly, the device constant values need to be appropriate for Figure 6. Workflow of ICTool program
the calculation formula. For application in work in Vietnam we can
simplify this calculation as follows: (1) for the Digitilt DataMate II
device of GeoSlope with the device constant of 25000, the value of
horizontal deviation, in millimeter unit, at each monitoring point
is (A0 – A180 )/100; (2) for GeoKon GK604-D equipment with the
device constant of 20000, the horizontal deviation value, millimeter
unit, at each monitoring point is (A + –A–)/80.

2.4 ICTool program

To respond well to the data processing of inclinometer systems for

basement diaphragm walls in Vietnam, the ICTool program has
been developed to calculate the monitoring data of the GK-604D
and DataMate II devices. The workflow of ICTool, as illustrated in
Figure 6, incorporates several important features.
For instance, the raw data file (input data) will be the source
of information that allows the program to automatically identify
the type of device used and automatically select the instrument
constant as well as the matching principle. It then calculates the
parameters that access cumulative deviation (known as an absolute
position) and/or cumulative displacement of inclinometers. Once Figure 7. Diagram of the excavation retaining wall structure with incli-
the reference epoch is selected, result graphs and data are plotted nometer borehole positions
and displayed on the interface. In addition, the program is also able
to export the results into reports. Exploring the full capabilities of
the ICTool program, the installer along with sample data has been in Figure 8, Kingpost strut-bracing systems were installed upon
uploaded to the OSF website (ICTool, 2023). completion of the excavation for phases 1 and 2 to stabilize the
diaphragm wall.
The process of monitoring was performed in 9 cycles from
3 Experimental results and discussion 30/12/2016 to 09/08/2017 with observation frequency of about one
month. The raw data of the borehole named ICL2 was selected to
Evaluating the calculation ability and the efficiency of the ICTool process (ICTool, 2023).
program, the observed data of the Geokon GK-604D instrument In the simplest case, we have processed the raw data for the first
was calculated by ICTool, Digipro2, and Sitemaster 2012 software. and the second cycles, in Table 1, which represents the correspond-
The experimental site for monitoring the displacement of the di- ing times before excavation and after completing the first stage
aphragm wall in the basement is located at 165 Xa Dan, Hanoi. At of excavation at a depth of -4.00 m. The instrument constants in
this site, the 800 mm thick diaphragm wall system was used as a DigiPro2 are configured to a value of 20000 as specified in the guid-
retaining structure for the excavation using the top-down method. ance provided by GeoKon. In addition, SiteMaster 2012 is always by
There are 9 boreholes which are arranged inside diaphragm wall default, while in ICTool, the raw data format is automatically iden-
plates with depths from 26.5 m to 27.5 m, as depicted in Figures 7 tified and applied. Ignoring the unstable value at the pipe top, the
and 8. results of cumulative displacement for the A axis are summarized
The excavation was conducted in three stages to the 1st, 2nd, in Table 2.
and 3rd floors of the basement at depths of -4.00 m, -8.5 m, and - Calculating the cumulative displacement using ICTool in Fig-
13.00 m, respectively. Following the geological conditions described ure 9, and SiteMaster 2012 gives a calculation difference of about
 Dinh Trong et al, 2023 | 73

Table 1. Raw data of the first cycle (December 30, 2016) and the second cycle (January 20,
2017) of the ICL2 borehole

*** ***
GK 604M(v1.3.0.8,02/17);2.0;FORMAT II GK 604M(v1.3.0.8,02/17);2.0;FORMAT II
PROJECT :165xd PROJECT :165xd
HOLE NO. :ICL2 HOLE NO. :ICL2
DATE :12/30/16 DATE :1/20/17
TIME :9:19:53 TIME :10:29:53
PROBE NO.:1609783 PROBE NO.:1609783
FILE NAME:i2_001.gkn FILE NAME:i2_002.gkn
#READINGS:57 #READINGS:57
FLEVEL, A+, A-, B+, B- FLEVEL, A+, A-, B+, B-
27.5, 677, -733, 758, -742 27.5, 681, -734, 769, -753
27.0, 651, -705, 739, -744 27.0, 655, -709, 749, -722
26.5, 635, -689, 721, -680 26.5, 639, -693, 731, -690
26.0, 631, -691, 729, -687 26.0, 633, -693, 739, -696
25.5, 611, -672, 727, -690 25.5, 615, -677, 737, -700
25.0, 522, -644, 722, -688 25.0, 521, -642, 732, -698
24.5, 582, -635, 775, -734 24.5, 586, -639, 785, -744
24.0, 564, -620, 734, -689 24.0, 567, -623, 744, -689
23.5, 550, -602, 625, -579 23.5, 554, -606, 633, -589
23.0, 515, -578, 437, -426 23.0, 512, -575, 447, -436
22.5, 472, -530, 191, -202 22.5, 475, -533, 201, -212
22.0, 426, -498, -102, 63 22.0, 432, -504, -92, 53
21.5, 403, -460, -514, 534 21.5, 402, -459, -504, 514
21.0, 370, -428, -749, 782 21.0, 374, -432, -739, 772
20.5, 332, -382, -930, 941 20.5, 332, -383, -920, 961
20.0, 287, -333, -1026, 1060 20.0, 291, -337, -1016, 1049
19.5, 258, -309, -1027, 1039 19.5, 255, -306, -1017, 1039
19.0, 216, -292, -920, 955 19.0, 221, -297, -910, 950
18.5, 214, -271, -701, 732 18.5, 219, -276, -691, 729
18.0, 165, -221, -541, 581 18.0, 166, -222, -532, 572
17.5, 87, -149, -368, 408 17.5, 93, -155, -358, 398
17.0, 37, -92, -211, 248 17.0, 30, -85, -201, 238
16.5, -32, -17, -74, 114 16.5, -25, -24, -64, 104
16.0, -67, 18, 31, -5 16.0, -71, 22, 41, -15
15.5, -110, 57, 122, -88 15.5, -115, 62, 98, -73
15.0, -116, 63, 98, -61 15.0, -116, 62, 98, -61
14.5, -115, 57, 122, -88 14.5, -113, 55, 132, -98
14.0, -90, 32, 162, -129 14.0, -92, 34, 172, -139
13.5, -52, 1, 193, -169 13.5, -56, 4, 203, -179
13.0, -19, -25, 194, -174 13.0, -17, -27, 207, -184
12.5, 29, -74, 179, -148 12.5, 33, -78, 189, -158
12.0, 80, -136, 164, -109 12.0, 84, -140, 174, -119
11.5, 160, -217, 128, -63 11.5, 163, -220, 138, -73
11.0, 229, -289, 83, -26 11.0, 237, -297, 94, -36
10.5, 301, -346, 46, 18 10.5, 308, -353, 56, 8
10.0, 319, -374, 33, 32 10.0, 328, -383, 43, 22
9.5, 330, -384, 36, -8 9.5, 337, -391, 46, -18
9.0, 331, -383, 102, -60 9.0, 334, -386, 112, -70
8.5, 320, -377, 163, -131 8.5, 323, -380, 173, -141
8.0, 321, -374, 223, -193 8.0, 323, -376, 233, -207
7.5, 346, -402, 287, -258 7.5, 340, -396, 297, -268
7.0, 320, -367, 332, -308 7.0, 336, -383, 342, -318
6.5, 295, -351, 388, -339 6.5, 293, -349, 398, -349
6.0, 312, -371, 399, -353 6.0, 317, -376, 409, -363
5.5, 329, -385, 416, -363 5.5, 330, -386, 426, -373
5.0, 319, -372, 422, -379 5.0, 327, -380, 432, -389
4.5, 311, -369, 411, -354 4.5, 329, -387, 421, -364
4.0, 280, -325, 415, -368 4.0, 305, -350, 425, -378
3.5, 231, -300, 334, -286 3.5, 255, -324, 344, -296
3.0, 232, -290, 144, -101 3.0, 254, -312, 154, -111
2.5, 211, -263, -54, 41 2.5, 233, -285, -44, 31
2.0, 189, -248, -243, 240 2.0, 214, -273, -233, 230
1.5, 156, -215, -358, 393 1.5, 177, -235, -348, 383
1.0, 121, -192, -446, 508 1.0, 134, -205, -436, 498
0.5, 115, -174, -490, 559 0.5, 124, -183, -480, 549
0.0, -734, NaN, -753, NaN 0.0, -734, NaN, -753, NaN
 74 | Reports on Geodesy and Geoinformatics, 2023, Vol. 116, pp. 69–76

Table 2. Summary of data processing of ICL2 inclinometer in-situ

Depth Cumulative displacement Calculation deviation

[m] [mm] [mm]
ICTool SiteMaster Digipro2 ICT- ICT- SM-
(ICT) 2012 (SM) (DP) SM DP DP

0.5 7.36 7.30 14.73 0.06 -7.37 -7.43

1 7.14 7.10 14.28 0.04 -7.14 -7.18
1.5 6.81 6.80 13.63 0.01 -6.82 -6.83
2 6.30 6.20 12.60 0.10 -6.30 -6.40
2.5 5.68 5.60 11.35 0.08 -5.68 -5.75
3 5.13 5.10 10.25 0.03 -5.13 -5.15
3.5 4.58 4.50 9.15 0.08 -4.58 -4.65
4 3.98 3.90 7.95 0.08 -3.98 -4.05
4.5 3.35 3.30 6.70 0.05 -3.35 -3.40
5 2.90 2.80 5.80 0.10 -2.90 -3.00
5.5 2.70 2.60 5.40 0.10 -2.70 -2.80
6 2.68 2.60 5.35 0.07 -2.68 -2.75
6.5 2.55 2.50 5.10 0.05 -2.55 -2.60
7 2.60 2.50 5.20 0.10 -2.60 -2.70
7.5 2.20 2.10 4.40 0.10 -2.20 -2.30
8 2.35 2.30 4.70 0.05 -2.35 -2.40
8.5 2.30 2.20 4.60 0.10 -2.30 -2.40
9 2.23 2.20 4.45 0.02 -2.23 -2.25
9.5 2.15 2.10 4.30 0.05 -2.15 -2.20
10 1.98 1.90 3.95 0.08 -1.98 -2.05
10.5 1.75 1.70 3.50 0.05 -1.75 -1.80
11 1.58 1.50 3.15 0.08 -1.58 -1.65
11.5 1.38 1.30 2.75 0.08 -1.38 -1.45
12 1.30 1.20 2.60 0.10 -1.30 -1.40
12.5 1.20 1.10 2.40 0.10 -1.20 -1.30
Figure 8. ICL2 analysed cross-section – geotechnical conditions and
13 1.10 1.00 2.20 0.10 -1.10 -1.20
construction elements
13.5 1.05 1.00 2.10 0.05 -1.05 -1.10
14 1.14 1.10 2.27 0.04 -1.13 -1.17
14.5 1.19 1.10 2.37 0.09 -1.18 -1.27
15 1.14 1.10 2.27 0.04 -1.13 -1.17
15.5 1.13 1.10 2.25 0.02 -1.13 -1.15
16 1.25 1.20 2.50 0.05 -1.25 -1.30
16.5 1.35 1.30 2.70 0.05 -1.35 -1.40
17 1.18 1.10 2.35 0.08 -1.18 -1.25
17.5 1.35 1.30 2.70 0.05 -1.35 -1.40
18 1.20 1.10 2.40 0.10 -1.20 -1.30
18.5 1.18 1.10 2.35 0.08 -1.18 -1.25
19 1.05 1.00 2.10 0.05 -1.05 -1.10
19.5 0.93 0.90 1.85 0.03 -0.93 -0.95
20 1.00 0.90 2.00 0.10 -1.00 -1.10
20.5 0.90 0.80 1.80 0.10 -0.90 -1.00
21 0.89 0.80 1.77 0.09 -0.88 -0.97
21.5 0.79 0.70 1.57 0.09 -0.78 -0.87
22 0.81 0.70 1.63 0.11 -0.82 -0.93
22.5 0.66 0.60 1.33 0.06 -0.67 -0.73
23 0.59 0.50 1.17 0.09 -0.58 -0.67
23.5 0.66 0.60 1.33 0.06 -0.67 -0.73
24 0.56 0.50 1.13 0.06 -0.57 -0.63
24.5 0.49 0.40 0.97 0.09 -0.48 -0.57
25 0.39 0.30 0.77 0.09 -0.38 -0.47
25.5 0.43 0.40 0.85 0.03 -0.43 -0.45
26 0.31 0.20 0.62 0.11 -0.31 -0.42
26.5 0.26 0.20 0.52 0.06 -0.26 -0.32
27 0.16 0.10 0.32 0.06 -0.16 -0.22
Figure 9. Ploted and calculated cumulative displacement using ICTool 27.5 0.06 0.00 0.13 0.06 -0.07 -0.13
between the first and the second cycles 28 0.00 0.00
 Dinh Trong et al, 2023 | 75

Figure 10. Calculation difference of ICTool and SiteMaster 2012 in com-

parison with DigiPro2 applied a device constant of 40000 for
the first and second cycles

0.1 mm while the calculated value by DigiPro2 is completely differ-

ent. The cause of tiny differences between ICTool and SiteMaster
2012 can be attributed to the rounding during the calculation and is
completely acceptable. In the data processing using Digipro2, some
differences have been pointed out. Firstly, with the monitoring data
at the depth of 27.5 m, SiteMaster 2012 and ICTool will assign "0" to
this value and start calculating the cumulative displacement from
the point with the depth of 27 m while the DigiPro2 will assign "0"
to the data at the depth of 28 m and start calculating the cumulative Figure 11. Calculation difference of ICL 2 between ICTool and DigiPro2
displacement from data at the depth of 27.5 m. This has shown that applied device constant of 40000 for 9 cycles
in the lateral displacement component at each depth point there is
a systematic difference of approximately 0.13 mm.
In addition, Table 2 shows that the cumulative displacement zontal deviation value in millimeters equal to (A0 – A180 )/100; (2)
value of DigiPro2 is about twice that of the two others. For this rea- with GK-604D instrument corresponding equals (A + –A–)/80. In
son, we reset the instrument constant to the value of 40000 during the case of GK-604D data processing with DigiPro2, it is necessary
the data processing for DigiPro2. Figure 10 shows the calculation to set the device constant to 40000.
differences between the ICTool and the DigiPro2 software (ICT- ICTool has been tested and used to process a lot of Geokon GK-
DP2) which has a maximum value of less than 0.005 mm while the 604D data in the movement monitoring of the basement diaphragm
maximum value (SM-DP2) between SiteMaster 2012 and DigiPro2 wall. ICTool only focuses on calculating cumulative displacement in
is about 0.10 mm. These deviations are very tiny in comparison the direction of pressure on basement diaphragm walls and brought
with bias and measuring errors (Grodecki et al., 2018; Moffat et al., the equivalent results to SiteMaster 2012 or DigiPro2 with a note of
2019) or technical requirements (Liu et al., 2011; Pei et al., 2021) of the adjusted instrument constant. It allows surveyors to process the
basement diaphragm wall monitoring so they can be omitted. diaphragm wall displacement data in Vietnam more conveniently.
The calculations were extended with raw data of 9 cycles of the DigiPro2 and SiteMaster 2012 (now version 2018) are commer-
ICL2 pipe using ICTool and then compared with the calculation cial software that are expensive and carry a limited trial period (30
results according to DigiPro2. Get assignment "0" point at the days for SiteMaster 2012 and 45 days for Digipro2). ICTool was built
depth of 28 m, obtained results as shown in Figure 11. The calcu- and will be provided free of charge for the communication of the
lated difference between the two software in Figure 11 is very small, monitoring of basement diaphragm wall displacement in Vietnam
within ±0.005 mm. This indicates that when processing data of the (ICTool, 2023).
Geokon GK-604D device using DigiPro2 software, it is necessary to
set up the instrument constant to 40000. In a similar comparison
between ICTool and SiteMaster, the calculation difference is within
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