ROCK MASS CLASSIFICATION ALONG PROPOSED HRT
S.No |
Rock Type |
Length in (m) |
Approx. %age w.r.t. Tunnel Length |
Groundwater probability |
RMR Values |
Class of rock % |
– |
|
|
|
Remarks |
|
|
|
|
|
|
I |
II |
III |
IV |
V |
|
1. |
Schistose Quartzite with subordinate bands of Biotite Schist. |
3600 |
12.0 |
Interstitial water seepage |
43 to 78 |
– |
8 |
3 |
1 |
– |
Schist bands thickness varies from few cms to 2m. Gneiss band of about 100m thickness. |
2. |
Biotite schist with subordinate bands of schistose Quartzite |
5290 |
17.0 |
Dry to dripping |
40 to 60 |
– |
– |
15 |
2 |
– |
Frequency of shearing expected relatively more. A band of carbonaceous phyllite is apprehended within this unit. |
3. |
Carbonaceous Phyllite, phyllite and phyllitic schist (Garneti ferrous) |
1060 |
3.0 |
Interstitial water seepage |
– |
– |
– |
– |
1 |
2.0 |
Upper & Lower contacts expected to be more shattered. |
4. |
Quartzite with subordinate bands of chlorite schist |
11440 |
37.0 |
Generally dry to dripping, at places moderately inflow. |
65 to 75 & rarely 80 & 40 |
3 |
24 |
5 |
5.0 |
– |
Quartzite-granite contact expected to be associated with talcose band of 10-20m thickness. |
5. |
Talc chlorite schist |
140 |
0.5 |
Moist |
– |
– |
– |
– |
– |
0.5 |
Thinly foliated rock with soapy feeling. |
6. |
Granite/Gneissose, Granite/Granitic gneiss with intermittent bands of Metabasics and chlorite schist. |
8820 |
28.0 |
Dry to dripping with Moderate inflow at places. |
63 to 85 |
|
|
|
|
|
|
Rarely < 60 |
5 |
20 |
3 |
– |
– |
Concordant bodies of metabasic & chloritic schist (1 to 10m) expected intermittently at an interval of 500-700m. |
|
|
|
|
|
7. |
Metabasics with intermittent bands of chlorite schist. |
880 |
2.5 |
Moist to dripping with low to moderate inflow at places |
52 to 67 with pockets of low values |
– |
|
1 |
|
1.5 |
Metabasic-quartzite contact is sheared/faulted and intermingled. |
|
TOTAL |
31230 |
100.00 |
|
|
8 |
52 |
27 |
9 |
4 |
|