The Use of Roughness Meter of Geophone Basis for Evaluating Functional Performance of Highways

The performance of a road link is globally divided into two categories: structural and functional. The structural performance is a condition shown by the condition of its remaining life, while the functional one relates to the comfort of road users passing on the pavement link. The roughness meter used is based on the censor of geophones and GPS, while the general roughness meters are based on accelerometer sensors such as ARRB, IRI meter, etc. The main reason to use the geophone is because the accelerometer and geophone are the sensors used to measure displacement. The theories behind this roughness meter are based on Watanabe et al. The retrieved data uses a stand-alone program based on Visual Basic 6. An Arduino Mega 2560 is used for the microcontroller, and the post-processing operation is programmed with MATLAB. Another advantage of this roughness meter is that the results of IRI values can be presented on a map, making it much easier for the road authority to determine the condition of the road links tested. This type of roughness meter has been tested for two road links in the Central Java province. Both of the two links have an average value of IRI of 3.7, which means that they are still in routine maintenance, but soon, they will get to the stage of minor rehabilitation.


1.
Introduction Roads are a unified road network system that connects and binds the entire territory of the Republic of Indonesia, and roads serve as goods and service distribution infrastructure [1].[2]Given the essential benefits, the road construction and maintenance sector should be researched and developed in planning, implementing, and maintaining it.However, as time goes by, the highway will experience a decrease in conditions according to the increase in the age of the road, making it an obstacle to the smoothness of the trip.The current state of the roads disturbs those who use them because many of them are damaged even though they are still in the design age.According to technical definitions, road damage denotes a situation where the functional and structural roads cannot give optimal service to the traffic that passes the road [3].
Both objective and subjective methods can be used to assess how well a road functions.The subjective method is based on the views of various experts on the ground, whereas the objective method measures pavement performance using a roughness measuring device [3].For instance, the roughness of the road surface can be used to objectively identify the [1], [3]- [15]pavement performance characteristics, while the pavement condition can be used to judge the parameters subjectively.

2.
Literature Review and Methodology The extent of road deterioration can be objectively assessed using a road condition index within predetermined parameters or ranges.According to the Transportation Association of Canada ( 2006), there are several different ways to measure the state of a road, including the RCI (Riding Comfort Index), SDI (Surface Distress Index), SCI (Structural Condition Index), PCI (Pavement Condition Index), IRI (International Roughness Index), and PQI (Pavement Quality Index).
There are disparities between the structural and functional conditions of the pavement based on these numerous criteria.When seen from the Remaining Services Life (RSL) perspective, these distinctions can be combined into a single index.According to Baladi, GY. (1991)[4], RSL is the annual value based on the volume of passing vehicles, with the pavement remaining in structural and functional service condition.The functional collapse approach, the structural collapse approach, and the functional and structural collapse approach are the three methods for obtaining the RSL value.
This study considers the pavement structural state using the pavement modulus, while the functional condition is assessed using the International Roughness Index (IRI) value.A geophone-based roughness meter would obtain The IRI value from a road surface unevenness survey.
The Road Condition Survey (RCS) is conducted to obtain data on damage to road pavements (volume and severity) and aims to develop plans and programs for road network development.The International Roughness Index (IRI) value is also needed to determine the road surface unevenness along the segment's longitudinal direction.This unevenness value is expressed in IRI with m/km as the units.
The Surface Distress Index (SDI), a system for evaluating the state of a road's pavement based on visual observations, can guide maintenance operations.Direct observation is used to evaluate the state of the road's surface, which is then classified based on the kind and severity of damage.Three key factors will be considered when calculating this study's results: the percentage of cracked area (%), the average crack width (mm), and the number of holes per 100 m.

3.
Assessment of the Crack Area (SDIa)

Number of Holes (SDIc)
Table 3 shows SDIC values based on the category of the number of holes on the road surface.

International Roughness Index (IRI) Assessment
The International Roughness Index (IRI), or surface unevenness, is an unevenness parameter calculated from the cumulative number of ups and downs in the direction of the longitudinal profile divided by the distance or length of the surface being measured.The classifications of road conditions based on IRI values are: IRI values <4 are "very good", IRI values 4-8 are "good-fair," IRI values 8-12 are "fair-poor", IRI values 12-16 are "poor-bad," IRI values 16-20 are "bad", IRI values ≥ 20 are "very bad", and IRI values Any are "unsealed".
Tables 4 and 5 below provide guidelines for treating road damage.

4.
Results and Analysis Geophone-based roughness meters are roughness meters used based on geophone and GPS sensors, while general roughness meters are based on accelerometer sensors such as ARRB, IRI meters, etc.The main reason for using geophones is because accelerometers and geophones are sensors for measuring displacement.The theory behind this roughness meter is based on Watanada et al.The data were taken using a stand-alone program based on Visual Basic 6. Arduino Mega 2560 was used for the microcontroller and post-processing operations, which were programmed with MATLAB.
Locations for this study include:

Data Researched
The data was taken by conducting a road surface roughness survey using a geophone-based roughness meter installed in a car with several devices.The description of the road route that will be surveyed using a geophone-based roughness meter is shown in the Google Maps image above (Figures 1 and 2).
Because road sections 1 and 2 are collector roads that can be passed by motorized vehicles with a maximum width of 2.5 m, a maximum length of 12 m, and a maximum weight of 8 tons, the highway research conducted at the study location is of the Class III B type.
The initial road section's data collection was conducted at a maximum speed of 60 km/hour and an average speed of 30 to 50 km/hour.The second road stretch should also be traveled at the same speed.The IRI value of the road surface roughness was divided in this investigation into units of about 100 meters.
The longitudinal surface's total number of rises and falls divided by the measured surface's length yields the unevenness parameter (IRI), which is computed as follows: The International Roughness Index (IRI) average of 3.7 indicates that the surface is in "very good" condition.The second set of information is a street map for the first road portion, as seen in the next picture.From the picture above, it can be seen that the green ones have the description "very good" in as many as 31 segments, then the yellow ones have the description "good-fair" in as many as 17 segments, and those with light damage have no description.From the picture above, it can be seen that the green ones have the description "Very good" in as many as 82 segments, then the yellow ones have the description "Good-fair" in as many as 47 segments, and those with light damage have no description.
From the survey results using a geophone-based roughness meter, two functional road conditions were obtained: "Very good" and "Good-fair," and the overall survey results on the first and second road sections, the IRI average value was obtained.As the calculation looks for the average value can be seen with the following calculations: IRI average value = ΣIRI/ɳ = 656/177 = 3.706 From the results of the calculation values above, the average value is obtained and correlated with the provisions of ASTM E 1926-8.The average roughness value is 3,706, which means the condition of the road section is in the "very good" road condition category.7 explains that the functional condition of the road presented in graphical form is 64% "very good" and 36% "good-fair."

6.
Summary and Recommendations 6.1.Summary According to the survey findings, calculations, and data analysis, the average value of the road section is "very good," with an IRI (International Roughness Index) value of 3,706.As a result, the handling is done using the method recommended by the Directorate General of Highways, which entails maintenance, periodic maintenance, and minor rehabilitation.

6.2.
Recommendations Some suggestions by the author for further research are: 1.For more accurate survey results, it is necessary to validate road condition data by carrying out comparative surveys to produce road conditions by existing conditions.2. The results of the road condition survey are updated every time to produce appropriate road conditions.This is necessary due to road conditions that can change due to weather factors, traffic levels, and other factors.3. Based on the road condition value, which is dominated by "very good" conditions with an average IRI value of 3,706, it has the potential to become "good-fair" with an IRI value of 4-8.Then over time, it will lead to a "very bad" condition with an IRI value ≥ 20. 4. To handle the results of this road condition, it is necessary to prioritize road conditions that have the potential to experience a decrease in road conditions so that road stability can be maintained and road damage does not multiply at high costs.5.While handling the road, it is necessary to carry out some tests, especially for damage to road pavements, to get the right handling method for the life of the road plan.

Figure 3 .
Figure 3.The International Roughness Index (IRI) on a first road section

Figure 4 .
Figure 4. 1 st Road Section Street Maps

Figure 5 .
Figure 5.The International Roughness Index (IRI) for 2 nd Road Section

Figure 6 .
Figure 6. 2 nd Road Section Street Maps

10 Figure 7 .
Figure 7.The Percentage of IRI Values Figure7explains that the functional condition of the road presented in graphical form is 64% "very good" and 36% "good-fair."

Table 2 .
Table 1 below shows SDI values based on the category of crack area on the road surface.Table 2 below shows the SDIb value dependent on the category of crack width on the road surface.Crack Width Assessment [11]ce: Bina Marga, 2011[11]