Laserfiche WebLink
In reference to the Longwall area, a subsidence monitoring network will be installed over the first panel to <br />provide data on the angle of draw and maximum subsidence. The location of the proposed monuments are <br />shown on Map 23A, Five Year Mine Plan; typical monument construction is provided on Figure 14. <br />The monuments will be spaced approximately 100 feet apart, except that the spacing will be narrowed to <br />50 feet at selected areas to better define the angle of draw. Also, monuments will be installed over pillars <br />in the gate entries. <br />In order to monitor subsidence and potential related effects due to extension of Panels 5 and 6 under the <br />designated Fish Creek AVF, three additional lines of subsidence monuments will be established as shown <br />on Map 23A, Five Year Mine Plan. A transverse line established perpendicular to the axis of Panels 5 and <br />6 will monitor both progressive and cumulative subsidence due to Panels 5 and 6 extraction. Two short <br />parallel lines established along the panel axis, will monitor start profiles for Panels 5 and 6 respectively. <br />Monuments will be located at approximately 100 foot intervals for AVF subsidence monitoring. <br />TCC may install additional monuments to provide information pertinent to mine planning. The data <br />generated by the additional monitoring will not be included with the subsidence reports. <br />3. County Road No. 27 and D.G.W. Railroad Spur <br />The structures will be visually inspected on a weekly basis during active mining of production areas <br />adjacent to them. <br />4. Yampa Valley Electric Association 69KV Powerline <br />As discussed in section 2.05.6(6) no production panels are planned to undermine the powerlines traversing <br />the Twentymile Park in the five -year mine plan; also, since the powerlines do not lie within the widest <br />possible angle of draw, no monitoring of powerline structures will be performed. <br />5. Archaeological Site 5RT345 <br />These features will not be disturbed. They fall beyond the angle of draw. <br />The subsidence monuments will be constructed to withstand normal outdoor weather conditions. A typical <br />monument is shown in Figure 14, Typical Subsidence Monument. <br />All monuments will be installed prior to secondary mining in a particular location. Monuments will be surveyed <br />quarterly, with the exception of AVF subsidence monuments which will be surveyed weekly for two months after <br />panel start. Severe winter conditions may preclude surveying monuments in hazardous or inaccessible areas. <br />Also, site specific conditions, such as holidays, may preclude compliance with this schedule. These conditions <br />will be discussed with the Division so that all parties agree the schedule can be modified. <br />TCC no longer plans to monitor monuments SP -2, SP -3, and SP -4. However, the monuments will be left intact <br />for further use, if necessarv. <br />Subsidence reports will be submitted to the CMLRD semi - annually. The reports will be submitted 60 days after <br />the end of the period, unless TCC contacts the Division and requests an extension of the submittal date. The <br />planned reporting format is shown in Exhibit 34, Subsidence Survey Report. <br />MR 97 -151 2.05 -186 9/9/97 <br />