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Geotechnical Engineering

 

Manual for Abandoned Underground Mine Inventory and Risk Assessment
Section 6: Detailed Site Evaluation

6.1 GENERAL DISCUSSION

The Detailed Site Evaluation process is begun by evaluating the Site Deformation, Mine Opening, and High Rating Site Groups in order of their Initial Site Evaluation risk assessment. This second level of site evaluation will reconsider, in some cases, some of the criteria considered during the Initial Site Evaluation, along with additional criteria related to the nature of the particular site group. Separate Detailed Site Evaluation Forms are provided for the Surface Deformation Group, Mine Opening Group, and High Rating Group. Each group of sites, in order of risk level, will proceed through the complete Abandoned Underground Mine Inventory process before the subsequent group is subjected to Detailed Site Evaluation. Some sites may require reevaluation and possible placement into a different risk assessment site group as the result of site information reviewed during the Detailed Site Evaluation.

6.2 DETAILED SITE EVALUATION CRITERIA

The Detailed Site Evaluation Criteria are utilized to evaluate site conditions and the public's exposure to those conditions.

6.2.1 Number of Subsidences:

This criterion is an indicator of the likelihood of current, or past, subsidence activity on the site. The rating value shall be the number of areas of surface settlement, subsidence, or irregular drainage conditions, which may be mine-related, and exist or have historically been observed in the right-of-way or within view of the right-of-way.

6.2.2 Recent Dewatering:

This criterion is an indicator of recent and historic fluctuations in groundwater conditions within the abandoned underground mine. Dewatering of the abandoned underground mine voids, and subsequent groundwater movements and possible recharging, either through natural processes or human activities, can have a very detrimental effect on the stability of natural and man-made supporting structures within the abandoned underground mine. These fluctuations in groundwater conditions can also affect the stability and integrity of the soil and rock units comprising the overburden interval between the roadway surface and the top of the abandoned mine void. The site condition is the length of time since each report or incidence of dewatering. The total rating value for a given site will be the sum of all rating values of all dewatering events.

Site Condition: Rating Value:
< 1 Year 10 Points
1 to 3 Years 9 Points
4 to 6 Years 4 Points
7 to 9 Years 2 Points
> 9 Years, unknown, or dry mine 1 Points

Example: A site was dewatered five years ago and again in the past year. The total site rating value for this criteria would be equal to 4 + 10, or 14.

6.2.3 Average Daily Volume of Traffic (ADT):

This criterion is a measure of the traveling public's exposure to the site. The site condition is the total average 24-hour volume of traffic for a given site as determined by the most recent Traffic Survey Report, plus a 3% per year calculated increase to date for the time elapsed since the issuance of the Traffic Survey Report.

Site Condition: Rating Value:
>30,000 Vehicles 10 Points
20,000 to 30,000 Vehicles 8 Points
10,000 to 20,000 Vehicles 6 Points
5,000 to 10,000 Vehicles 4 Points
<5,000 Vehicles 2 Points

6.2.4 Classification of Roadway:

This criterion is an indicator of the strategic significance of the roadway site to the state and interstate highway transportation systems. The site condition for this criterion is defined as four classifications of roadway. The "NHS Other Than Interstate" site condition should be utilized for National Highway System routes other than the Interstate highway system. In the case of intersecting roadways, the overall site condition rating value should be calculated as the sum of the individual site condition rating values for each of the intersecting roadways.

Site Condition: Rating Value:
Interstate (I.R.) 10 Points
NHS Other Than Interstate 7 Points
Arterial 5 Points
Collector 1 Point

Examples:

  1. Given: An intersection of an interstate roadway and an arterial roadway is within the site area. The total site rating value for this criteria would be equal to 10 + 5 , or 15.

  2. Given: An intersection of two arterial roadways is within the site area. The total site rating value for this criteria would be equal to 5 + 5 , or 10.

6.2.5 Average Daily Volume of Truck Traffic (ADTT):

This criterion is a measure of a possible sudden collapse of the pavement due to impact loading. The site condition is the average 24-hour total volume of "B"and "C" commercial traffic for a given site as determined by the most recent Traffic Survey Report.

Site Condition: Rating Value:
>6,000 Vehicles 10 Points
4,000 to 6,000 Vehicles 8 Points
2,000 to 4,000 Vehicles 6 Points
1,000 to 2,000 Vehicles 4 Points
<1,000 Vehicles 2 Points

6.2.6 Traffic Speed: 

This criterion is an indicator of a driver's ability to perceive and avoid a roadway subsidence area. The site condition is the maximum legal speed limit within the section of roadway defining the site.

Site Condition: Rating Value:
>35 MPH 10 Points
0 to 35 MPH 1 Point

6.2.7 Type of Pavement:

This criterion is an indicator of the pavement's ability to bridge a subsidence or to survive deformation caused by subsidence. The site condition is the type of pavement existing on the site.

Site Condition: Rating Value:
All forms of pavement
other than continuous
10 Points
Continuously Reinforced Pavement 1 Point

6.2.8 Ratio of Unconsolidated Materials to Bedrock in The Overburden Interval:

This criterion is utilized as an indicator of subsidence potential. For the use of this criterion, overburden is considered as being composed of only two types of material: 1) unconsolidated material, or; 2) intact bedrock. The subsidence potential will be relatively greater for sites where a larger portion of the overburden is comprised of unconsolidated materials.

Three elevations must be estimated to rate this criterion for a given site. These elevations are for: 1) the roadway surface; 2) the top of the mined interval, and; 3) the bedrock topographic surface within the overburden interval existing between the roadway and the top of the mined interval. The roadway surface elevation may be estimated through review of existing ODOT roadway drawings and U.S.G.S. Quadrangle maps. The top of the mined interval may be estimated through review of several ODNR, DGS forms of information, including individual abandoned underground mine maps and their associated data sheets, bedrock topography maps, geological structure maps, measured geological sections, on-site geological field observations, and other sources of mining/coal information. The elevation of the bedrock topographic surface in the overburden interval may be estimated through review of the ODNR, DGS bedrock topography maps.

The more commonly available forms of surface topographic and bedrock topographic information are larger scaled maps which utilize coarse incremental values. Therefore, the elevations used to calculate the ratio defining the site condition for this criterion will be only approximate. This fact will only allow for an informed "best guess" estimation of the ratio of unconsolidated materials to bedrock in the overburden interval. However, sites which have an overburden interval comprised of a larger portion of unconsolidated materials can be screening for higher risk of subsidence through the use of this criteria. If the apparent unconsolidated material to bedrock estimated ratio appears from available information to be approximately equal to one, the site condition will be rated the same as if the ratio was greater than one.

Site Condition: Rating Value:
Ratio >1 10 Points
Ratio <1 1 Point

Example of Site Evaluation: 

Review of the above described information has revealed the following information for a given site: elevation of roadway is 760, elevation of mine floor (from ODNR, DGS mine map) is 725, thickness of mined interval is 5 feet (from ODNR, DGS mine map data sheets, geological structure maps, measured geological sections, and/or on-site geological field observations), and the elevation of the bedrock topographic surface is 740. The site condition for this criterion would be thus determined:

  1. Top of Mined interval = mine floor + thickness of mined interval = 725+5 =730

  2. Full depth of Overburden = 760-730 = 30 feet

  3. Thickness of Unconsolidated Materials in Overburden = 760-740 = 20 feet

  4. Thickness of Bedrock in Overburden = 740-730 = 10

  5. Site Condition = Unconsolidated Material to Bedrock Estimated Ratio = 20 feet / 10 feet = 2

  6. Rating Value = 10 points

6.2.9 Availability of Reasonable Detour Routes:

This criterion is an indicator of the strategic significance that lost use of the roadway site would have on the local flow of traffic. The rating of this criteria is a judgment call. The decision should be based on the need for a three month required road closure in the case of a sudden, unplanned road collapse.

Site Condition: Rating Value:
None 10 Points
Yes (Available) 0 Point

6.2.10 Structures in Roadway: 

This criterion is an indicator of the presence of structures, as defined by the ODOT Bridge Inventory Manual and Appraisal Coding Guide, which could be affected by a subsidence event. The definition of "structure", as defined in these referenced publications, states:

"For the purposes of this inventory, a bridge is defined as: any structure, including supports, of 10 feet or more clear span or 10 feet or more ( clear opening ) in diameter on, above, or below a highway. The span of all bridges, except culverts regarded as bridges, shall be measured along the centerline of the highway. Culvert span(s) shall be measured normal to the axis of the culvert.".

Worst case conditions should be assumed in determining if a structure will be affected by a subsidence event. This information is considered significant because structures sensitive to differential settlement, if they were to become unstable, would pose a threat to the safety of the traveling public and a significant financial loss to the State if damaged.

Site Condition: Rating Value:
Yes 10 Points
No 0 Point

6.2.11 Minimum Overburden Thickness (Approx.):

This criterion is an indicator of the potential for subsidence. The site condition is the vertical interval of overburden between the roadway surface elevation and the top of the abandoned underground mine void existing below the roadway. Possible sources of information would include: ODNR, Division Geological Survey information, such as individual abandoned underground mine maps, coal outcrop elevation from topographic information or structure maps, measured geologic sections, etc.; ODNR, Division of Mining and Reclamation information, such as limits of nearby, active surface mine operations ; and contacts with individuals knowledgeable of local, historical mining operations.

Site Condition: Rating Value:
< 25 Feet 10 Points
25 Feet to 50 Feet 8 Points
50 Feet to 100 Feet 5 Points
>100 Feet 1 Point

6.2.12 Mine Opening Location:

This criterion is an indicator of the relative risk to the safety of the traveling public. The site condition is the location of the mine opening relative to the roadway. In the case of multiple mine openings, the overall site condition rating value should be calculated as the sum of the individual site condition rating values for each of the mine openings on the site. The highest potential rating value should be used when a mine opening's location is not conclusively known.

Site Condition: Rating Value:
Location not Conclusively Known 10 Points
Between the Two Outer-Most Edge of Shoulders 10 Points
Less than 50' Feet From Edge of Shoulder 8 Points
Between 50' and 100' From Edge of Shoulder 2 Points
Within Sight From Edge of Shoulder 1 Point

6.2.13 Method of Mine Closure:

This criterion is an indicator of the current stability of any materials originally placed to seal the mine opening. In the case of multiple mine openings, the overall site condition rating value should be calculated as the sum of the individual site condition rating values for each of the mine openings on the site.

Site Condition: Rating Value:
No Information 10 Points
Timber Decking 10 Points
Uncontrolled Random Backfill 6 Points
Concrete Cap 4 Points
Controlled Backfill 2 Points

6.2.14 Type of Cribbing:

This criterion is an indicator of the current stability of materials originally placed to provide vertical or lateral support of the mine opening. In the case of multiple mine mine openings, the overall site condition rating value should be calculated as the sum of the individual site condition rating values for each of the mine openings on the site.

Site Condition: Rating Value:
No Information 10 Points
Timbers 10 Points
Brick 7 Points
Concrete 4 Points

6.2.15 Minimum Overburden Above Mine Opening:

This criterion is an indicator of the potential for subsidence. The site condition is the minimum vertical interval of overburden between the elevation of roadway surface and flowlines of drainage structures, and the top of the abandoned underground mine opening existing below the roadway.

Site Condition: Rating Value:
Shaft / Cover = 0 Feet 10 Points
Slope/Drift: Cover < 25 Feet 9 Points
Slope/Drift: Cover = 25 Feet to 50 Feet 8 Points
Slope/Drift: Cover = 50 Feet to 100 Feet Points
Slope/Drift: Cover >100 Feet 1 Point

6.2.16 Type of Mine Opening:

This criterion is an indicator of the relative danger posed to the safety of the traveling public by the original type of mine opening. In the case of multiple mine openings, the overall site condition rating value should be calculated as the sum of the individual site condition rating values for each of the mine openings on the site.

Site Condition: Rating Value:
Shaft (Vertical) Entry 10 Points
Slope Entry 8 Points
Drift (Horizontal) Entry 6 Points

6.2.17 Plan Area of Mine Opening (Approx.):

This criterion is an indicator of the potential size of surface feature which could occur and the volume of material which could be drawn into the mine opening in the case of a catastrophic collapse. Such a collapse might occur due to failure of the existing backfill, cribbing, and/or closure at the mine opening entrance. The site condition is the plan area of the original mine opening. In the case of multiple mine openings, the overall site condition rating value should be calculated as the sum of the individual site condition rating values for each of the mine openings on the site.

Site Condition: Rating Value:
>750 Sq. Ft. 10 Points
From 500 to 750 Sq. Ft. 8 Points
From 250 to 500 Sq. Ft. 6 Points
Mine Opening size unknown 5 Points
From 150 to 250 Sq. Ft. 4 Points
<150 Sq. Ft. 2 Points

6.2.18 Age of Mining:

This criterion is an indicator of the mining methods utilized and the condition of the mine due to length of time elapsed since abandonment. The site condition is the year of abandonment. This criteria reflects relative differences in: mining methods, probable deterioration due to age: and the possibility of unrecorded mining

Site Condition: Rating Value:
<1900, or unknown 10 Points
1900 to 1930 9 Points
1931 to 1945 7 Points
1946 to 1968 5 Points
>1968 1 Point

6.2.19 Extraction:

This criterion is an indicator of the amount of mine roof support which remains in the mine. Evidence of the rate of mineral extraction and secondary removal of supporting blocks or pillars left by the original mining operation for roof support may be obtained for some sites. This information will probably be determined primarily through review of: 1) individual mine maps; 2) information from the ODNR, Division of Geological Survey and 3) information obtained from local individuals who are, or have been, involved in the mining of the mineral seam.

Site Condition: Rating Value:
Evidence of Secondary Mining 10 Points
Rate of Mineral Extraction > 50% 7 Points
Unknown 5 Points
Rate of Mineral Extraction < 50% 1 Point

6.2.20 Maximum Mined Interval Thickness (Approx.):

Thicker seams would be expected to have a higher likelihood of surface deformation. The approximate maximum mined interval (void height) of the abandoned underground mine will probably be determined through review of; 1) individual mine maps; 2) information from the ODNR, Division of Geological Survey and 3) information obtained from local individuals who are, or have been, involved in the mining of the mineral seam.

Site Condition: Rating Value:
>6 Feet 10 Points
3 Feet to 6 Feet 5 Points
0 Feet to 3 Feet 1 Point

6.2.21 Special Mine Features:

This criterion is an indicator of the presence of larger unsupported mine roof areas that are more likely to collapse beneath the right-of way. The source of this information will primarily be individual mine maps. The site condition is the feature beneath the roadway having the highest rating value.

Site Condition: Rating Value:
Intersecting Haulways 10 Points
Entry 5 Points
Large Room 5 Points
None 0 Point

6.2.22 Problems Reported During Active Mining:

This criterion is a measure of potential abandoned underground mine instability related to geological conditions. Some of these conditions may include the vertical movement of groundwater down through the overburden, horizontal groundwater movements through the coal seam and unstable mine conditions indicating inherent or induced instability in the mined strata and associated geologic units overlying the mined interval. The condition is any confirmed report of mine instability or significant groundwater problems during active mining.

Site Condition: Rating Value:
Yes 10 Points
No/Not Known 0 Point

6.2.23 Ratio of Minimum Overburden Thickness toMaximum Mined Interval Thickness (Approx.):

This criterion is utilized to give an indication of the potential for highly differential subsidence features at the surface. These subsidence features are also commonly referred to as "sinkholes." The site condition is the estimated ratio of overburden thickness (h) to mining height (m), or "h/m" (Matheson and Eckert-Clift,1986; Peng, 1992).

The overburden thickness (h) is the minimum vertical interval between the roadway surface elevation and the top of the abandoned underground mine void existing below the roadway. The thickness of mined interval (m) is the approximate maximum void height of the abandoned underground mine. Possible sources of information include: ODNR, Division Geological Survey information, such as individual abandoned underground mine maps, coal outcrop elevation from topographic information or structure maps, measured geologic sections, etc.; ODNR, Division of Mining and Reclamation information, such as limits of nearby, active surface mine operations ; and contacts with individuals knowledgeable of local, historical mining operations.

Site Condition: Rating Value:
Ratio < 5 10 Points
Ratio = 5 to 11 5 Points
Ratio > 11 1 Point

6.3 DETAILED SITE EVALUATION WEIGHTING FACTORS

The weighting factors for each site group are indicated in Table 6.1. The numbers appearing in the boxes following given site criteria indicate the weighting factor values utilized for the particular site groups.

Table 6.1

Detailed Site Evaluation Criteria and Weighting Factors By Site Group

Criterion Surface Deformation Group Mine Opening Group High Rating Group
Number of Subsidences 30    
Recent Dewatering 21 8 10
Average Daily Traffic (ADT) 15 10 9
Classification of Roadway 12 9 9
Average Daily Truck Traffic (ADTT) 9 6 5
Traffic Speed 6 5 3
Type of Pavement 6 6 5
Ratio of Unconsolidated Materials to Bedrock in the Overburden Interval 6   8
Availability of Reasonable Detour Routes 6 2 3
Structures in Roadway 3 6 3
Minimum Overburden Thickness (Approx.) 2   4
Method of Mine Closure   10  
Type of Cribbing   10  
Mine Opening Location   9  
Minimum Overburden above Mine Opening   8  
Type of Mine Opening   5  
Plan Area of Mine Opening (Approx.)   4  
Age of Mining   4 8
Extraction     8
Maximum Mined Interval Thickness (Approx.)     8
Special Mine Features     2
Problems Reported During Active Mining     2
Ratio Of Minimum Overburden Thickness to Maximum Mined Interval Thickness (Approx.)     6

6.4 DETAILED SITE EVALUATION FORMS

A Detailed Site Evaluation Form shall be completed for each site determined to be in either the Surface Deformation Group, Mine Opening Group, or the High Rating Group. A blank Detailed Site Evaluation form is provided for each of these three site groups as Figures 6.1, 6.3, and 6.5 . These forms are structured with a beginning section of site information, an Eliminated Sites Screening section, and then the main section listing the site evaluation criteria pertinent to the nature of the site. Corresponding examples of completed forms are provided as Figures 6.2, 6.4, and 6.6.

These forms are designed to develop an overall Detailed Site Evaluation rating based on the totaling of rating values for each listed individual site evaluation criterion. Each individual criterion rating value is calculated by multiplying a weighting factor times a rating value which represents a site condition. The weighting factors reflect the importance of the different criteria as related to one another for the given type of site. The completion of these forms will produce a prioritized site listing for each site group.

6.4.1 Eliminated Sites Screening:

The Surface Deformation Group Site Evaluation may result in the elimination of a small percentage of sites from this site group. The initial portion of the Surface Deformation Group Site Evaluation form pertains to the documentation of a site being designated as an eliminated surface deformation site. The decision to eliminate a site from the Surface Deformation Group indicates that site investigations and/or interviews have conclusively proven that the surface deformation at this site is not an apparent threat to the safety of the roadway. The exact location , orientation and limits of influence should be verified in the field and a determination should be made that any further surface settlement would not affect the roadway or roadside development.Similarly, the Detailed Mine Opening Group Site Evaluation process may result in the elimination of a small percentage of mine opening sites from this site group. The initial portion of the Detailed Mine Opening Group Site Evaluation form pertains to the documentation of a site being designated as an eliminated mine opening site. The decision to eliminate a site from the Mine Opening Group indicates that site investigations and/or interviews have conclusively proven that the identified mine opening(s) at this site is (are) not an apparent threat to the safety of the roadway. The exact location , orientation, and limits of influence should be verified in the field. The coordinating District engineer should make a determination that the collapse of the located mine opening or mine closure would not affect the roadway or roadside development.

One pitfall to avoid in this part of the Detailed Site Evaluation of Surface Deformation and Mine Opening Sites is the elimination of sites without conclusive information indicating that the surface deformation activity or abandoned underground mine opening does not pose a threat to the roadway, and therefore the traveling public. If the available information for a given site does not provide conclusive proof that the surface deformation or mine opening is of no threat to the roadway, and therefore the traveling public, then the site should not be eliminated from the site group into which it has been placed.

All sites which are eliminated from the Surface Deformation Group Site Evaluation will be separately considered as non-surface deformation Abandoned Underground Mine Inventory sites. Similarly, all sites which are eliminated from the Detailed Mine Opening Group Site Evaluation will be separately considered as non-mine opening Abandoned Underground Mine Inventory sites.

Ohio Department of Transportation
Abandoned Underground Mine Inventory and Risk Assessment

Detailed Surface Deformation Site Evaluation


C/R/S/ (Mile Marker): _______________________________ Field Report / Office Investigation No.__________________________
Site Description: ____________________________________________________________________________________________
__________________________________________________________________________________________________________
U.S.G.S. Topographic
Quadrangle ODOT No.:______________
O.D.N.R. Abandoned Underground
Mine Series (U.S.G.S.) Map:______________
O.D.N.R.,DGS Individual Abandoned
Underground Mine Map Index No.:______________
(If known.)

Name of Site Evaluator:________________________________________________Evaluation Date:________________

ELIMINATED SURFACE DEFORMATION SITE SCREENING
NOTE: Have site investigations and /or interviews conclusively proven that the identified mine(s) at this site is (are) not an apparent threat to the safety of the roadway? Yes_____ (SEE COMMENTS BELOW FOR BASIS OF THIS FINDING)
No______
NOTE: Checking "Yes" to this question indicates that exact location, orientation and limits of influence have been verified in the field and a determination made that collapse of the opening or the closure would not affect the roadway or roadside development.
  Criterion Criterion
Weighting
Factor
Site Condition / Rating Value Individual Criterion Rating
1)   Number of Subsidences 30 Number of Subsidence Features on Site  
2)   Recent Dewatering 21 <1 Yr.
10
1 to 3 Yrs.
9
4 to 6 Yrs.
4
7 to 9 Yrs.
2
>9 Yrs.,
Unknown,
or Dry Mine

1
 
3)   Average Daily Traffic (ADT) 15 >30K
10
20K to 30K
8
10K to 20K
6
5K to 10K
4
< 5K
2
 
4)   Classification of Roadway (NOTE: For intersecting Roads, See Implementation Manual) 12 I.R.
10
NHS Other
Than IR

7
Arterial
5
Collector
1
   
5)   Average Daily Truck Traffic (ADTT) 9 >6K
10
4K to 6K
8
2K to 4K
6
1K to 2K
4
< 1K
2
 
6)   Traffic Speed 6 >35 MPH
10
0 to 35 MPH
1
       
7)   Type of Pavement 6 Other
10
Continuously Reinforced
1
       
8)   Ratio of Unconsolidated Materials to Bedrock in the Overburden Interval 6 Ratio = 1 or > 1
10
Ratio <1
1
       
9)   Availability of Reasonable Detour Routes 6 None
10
Yes
0
       
10)   Structures in Roadway 3 Yes
10
No
0
       
11)   Minimum Overburden Thickness (Approx.) 2 < 25'
10
25' - 50'
8
50' - 100'
5
>100'
1
   
Overall (Total) Site Evaluation Rating:    
COMMENTS (Attach additional sheets if necessary):
5/15/98
Figure 6.1: Detailed Surface Deformation Site Evaluation Form


Example of a Completed Detailed Surface Deformation Site Evaluation Form

Figure 6.2: Example of a Completed Detailed Surface Deformation Site Evaluation Form

Ohio Department of Transportation
Abandoned Underground Mine Inventory and Risk Assessment

Detailed Mine Opening Site Evaluation



C/R/S/ (Mile Marker): _______________________________ Field Report / Office Investigation No.__________________________
Site Description: ____________________________________________________________________________________________
__________________________________________________________________________________________________________
U.S.G.S. Topographic
Quadrangle ODOT No.:______________
O.D.N.R. Abandoned Underground
Mine Series (U.S.G.S.) Map:______________
O.D.N.R.,DGS Individual Abandoned
Underground Mine Map Index No.:______________
(If known.)

Name of Site Evaluator:________________________________________________Evaluation Date:________________

ELIMINATED MINE OPENING SITE SCREENING
NOTE: Have site investigations and /or interviews conclusively proven that the identified mine opening(s) at this site is (are) not an apparent threat to the safety of the roadway? Yes_____ (SEE COMMENTS BELOW FOR BASIS OF THIS FINDING)
No____
NOTE: Checking "Yes" to this question indicates that exact location, orientation and limits of influence have been verified in the field and a determination made that collapse of the opening or the closure would not affect the roadway or roadside development.
  Criterion Criterion
Weighting
Factor
Site Condition / Rating Value Individual Criterion Rating
1)   Method of Mine Closure
( NOTE: For Multiple Mine Openings See Implementation Manual)
10 No Information
10
Timber Decking
10
Random Backfill
6
Concrete Cap
4
Controlled Backfill
2
   
2)   Type of Cribbing
( NOTE: For Multiple Mine Openings and/or Multiple Forms of Cribbing See Implementation Manual)
10 No Information
10
Timbers
10
Brick
7
Concrete
4
     
 
3)   Average Daily Traffic (ADT) 10 >30K
10
20K to 30K
8
10K to 20K
6
5K to 10K
4
< 5K
2
   
4)   Mine Opening Location
( NOTE: For Multiple Mine Openings See Implementation Manual)
9 Location Not Conclusively Known
10
Between The Two Outer-Most Edge of Shoulders
10
Less Than 50 Feet From Edge of Shoulder
8
Between 50' and 100' From Edge of Shoulder From Edge of Shoulder
2
Within Sight From Edge of Shoulder
1
   
5)   Classification of Roadway ( NOTE: For intersecting Roads, See Implementation Manual) 9 I.R.
10
NHS Other Than IR
7
Arterial
5
Collector
1
     
6)   Minimum Overburden above Mine Opening 8 Shaft or Cover = 0'
10
Slope/Drift Cover < 25'
9
Slope/Drift Cover = 25' - 50'
8
Slope/Drift Cover = 50' - 100'
5
Slope/Drift Cover >100'
1
   
7)   Recent Dewatering 8 <1 Yr.
10
1 to 3 Yrs.
9
4 to 6 Yrs.
4
7 to 9 Yrs.
2
>9 Yrs., Unknown, or Dry Mine
1
   
8)   Average Daily Truck Traffic (ADTT) 6 >6K
10
4K to 6K
8
2K to 4K
6
1K to 2K
4
< 1K
2
   
9)   Type of Pavement 6 Other
10
Continuously Reinforced
1
         
10)   Structures in Roadway 6 Yes
10
No
0
         
11)   Traffic Speed 5 >35 MPH
10
0 to 35 MPH
1
         
12)   Type of Mine Opening ( NOTE: For Multiple Mine Openings) See Implementation Manual) 5 Shaft (Vertical)
10
Slope
8
Drift (Horizontal)
6
       
13)   Plan Area of Mine Opening (Approx.) ( NOTE: For Multiple Mine Openings See Implementation Manual) 4 >750 Sq. Ft.
10
From 500 to 750 Sq. Ft.
8
From 250 to 500 Sq. Ft.
6
Mine Opening Size Unknown
5
From 150 to 250 Sq. Ft.
4
<150 Sq. Ft.
2
 
14)   Age of Mining 4 <1900, or Unknown
10
1900-1930
9
1931-1945
7
1946-1968
5
> 1968
1
   
15)   Availability of Reasonable Detour Routes 2 None
10
Yes
0
         
Overall(Total) Site Evaluation Rating:    
COMMENTS (Attach additional sheets if necessary):
5/15/98
Figure 6.3: Detailed Mine Opening Site Evaluation Form


Example of a Completed Detailed Mine Opening Site Evaluation Form page 1 of 2

Figure 6.4: Example of a Completed Detailed Mine Opening Site Evaluation Form
Page 1 of 2

Example of a Completed Detailed Mine Opening Site Evaluation Form page 2 of 2

Figure 6.4: Example of a Completed Detailed Mine Opening Site Evaluation Form
Page 2 of 2

Ohio Department of Transportation
Abandoned Underground Mine Inventory and Risk Assessment

Detailed High Rating Site Evaluation


C/R/S/ (Mile Marker): _______________________________ Field Report / Office Investigation No.__________________________
Site Description: ____________________________________________________________________________________________
__________________________________________________________________________________________________________
U.S.G.S. Topographic
Quadrangle ODOT No.:______________
O.D.N.R. Abandoned Underground
Mine Series (U.S.G.S.) Map:______________
O.D.N.R.,DGS Individual Abandoned
Underground Mine Map Index No.:______________
(If known.)

Name of Site Evaluator:________________________________________________
Evaluation Date:________________
  Criterion Criterion
Weighting
Factor
Site Condition / Rating Value Individual Criterion Rating
1)   Minimum Overburden Thickness (Approx.) 4 < 25'
10
25' - 50'
8
50' - 100'
5
>100'
1
   
2)   Recent Dewatering 10 <1 Yr.
10
1 to 3 Yrs.
9
4 to 6 Yrs.
4
7 to 9 Yrs.
2
>9 Yrs.,
Unknown,
Dry Mine

1
 
3)   Average Daily Traffic (ADT) 9 >30K
10
20K to 30K
8
10K to 20K
6
5K to 10K
4
< 5K
2
 
4)   Classification of Roadway
( NOTE: For intersecting Roads, See Implementation Manual)
9 I.R.
10
NHS Other Than IR
7
Arterial
5
Collector
1
   
5)   Extraction 8 Secondary
10
>50%
7
Unknown
5
<50%
1
   
6)   Maximum Mined Interval Thickness (Approx.) 8 >6'
10
3' - 6'
5
0' - 3'
1
     
7)   Age of Mining 8 <1900, or Unknown
10
1900-1930
9
1931-1945
7
1946-1968
5
> 1968
1
 
8)   Ratio of Unconsolidated Materials to Bedrock in the Overburden Interval 8 Ratio= 1 or > 1
10
Ratio <1
1
       
9)   Ratio of Minimum Overburden Thickness To Maximum Mined Interval Thickness(Approx.) 6 Ratio < 5
10
Ratio = 5 to 11
5
Ratio >11
1
     
10)   Average Daily Truck Traffic (ADTT) 5 >6K
10
4K to 6K
8
2K to 4K
6
1K to 2K
4
< 1K
2
 
11)   Type of Pavement 5 Other
10
Continuously Reinforced
1
       
12)   Structures in Roadway 3 Yes
10
No
0
       
13)   Traffic Speed 3 >35 MPH
10
0 to 35 MPH
1
       
14)   Availability of Reasonable Detour Routes 3 None
10
Yes
0
       
15)   Special Mine Features 2 Intersecting Haulways
10
Entry
5
Large Room
5
None
0
   
16)   Problems Reported During Active Mining 2 Yes
10
No/Not Known
0
       
Overall (Total) Site Evaluation Rating:    
COMMENTS (Attach additional sheets if necessary):
5/15/98
Figure 6.5: Detailed High Rating Site Evaluation Form


Example of a Completed Detailed High Rating Site Evaluation Form page 1 of 2

Figure 6.6: Example of a Completed Detailed High Rating Site Evaluation Form
Page 1 of 2

Example of a Completed Detailed High Rating Site Evaluation Form page 1 of 2

Figure 6.6: Example of a Completed Detailed High Rating Site Evaluation Form
Page 2 of 2

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Updated: 04/07/2011

FHWA
United States Department of Transportation - Federal Highway Administration