International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B1, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
y7 0.0352x- 1.7816
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Figure 2. Basic idea of Chow-Test
SSR2: residual sum of squares in range A
SSR : residual sum of squares in whole range
nl : number of data in range A
n2 : number of data in range B
k :number of explanatory variable
Here, the following hypotheses are set.
Null hypothesis HO
: pavement condition of range A and range B is equal
Alternative hypothesis H1
: pavement condition of range A and range B is different
F-value is computed by result of regression analysis and in the
case that the hypothesis is rejected using a level of significance
of 0.05, it is considered that that pavement of road is damaged.
Also, the level of damage of surface condition is evaluated by
F-value and the rate of the number of rejected points.
4. CASE STUDY
4.1 Outline of Case Study
The evaluation model proposed in this research is applied for
actual road pavement. 3D point clouds from MMS are measured
and pavement condition is evaluated by Chow-test using
collections of data for road pavement managed by local
government. Furthermore, the results between Chow-test and
existing method of pavement condition survey were compared
and the validity of evaluation method proposed in this research
was assessed.
The target road for evaluation has length of 6km managed by
local government and that road is semi- highway which had one
lane for one direction. That road was constructed 30 years over
ago and the damaged pavement sections were repaired by
cutting overlay and replacement. Also, the road surface was dug
up for construction, such as a gas pipe and burial of a sewer
pipeline, and many marks of the construction were noticed
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existing. The irregularity points of pavement are attributed to
not only deterioration but marks of the construction.
The pavement condition survey in Japan evaluates the condition
by Maintenance Condition Index (MCI)) and integrates the
evaluation result of cracking, rutting and IRI. This MCI varies
in the range from 10 to 0. The larger value of MCI indicates that
the condition is better. This case study compares the results
between Chow-test using 3D point clouds and MCI.
4.2 Result of analysis
The results of Chow-test for arbitrary pavement section are
shown in Figure 3 - Figure 5. These figures indicate F-value and
coordinate value (XZ) of 3D point clouds. The horizontal axis
shows the cross direction of road and the vertical axis shows the
coordinate of Z and F-value. The section in Figure 3 has one
point where is dented on surface and the F-value of that point
shows large. In the case of Figure 4, the bump points are in
some points on surface and F-values are also dispersed to
horizontal direction. On the other hand, in the section in Figure
5, there is one point which has extremely the large number of F-
value. That means there is a localized damaged point.
Figure 6 makes a comparison between MCI evaluated by
pavement condition survey and the result by Chow-test. It is
impossible to analyze the correlation directly between MCI and
F-value due to difference of evaluation section range
(evaluation length of pavement condition survey is 50m). For
this reason, the whole tendency is represented by illustrating an
evaluation result.
The upper part of Figure 6 indicates the maximum of F-value
and the lower part indicates the rate of points which has bump
on surface. There is no clear relationship between the maximum
of F-value and MCI because MCI represents the average
condition of pavement section, not localized damaged point. On
the other hand, in the lower figure which shows the relation
between the rates of points, has bump on surface and MCI, the
evaluation result of Chow-test is consistent with MCI. From the
above results, it can be said that the methodology proposed in
this study makes it possible to evaluate pavement conditions by
considering not only macro (average) but micro (localized)
level. This indicated the possibility to evaluate the localized
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