National Green Tribunal
Diwan Singh vs State Of Uttarakhand on 16 July, 2024
Item No. 08 Court No. 2
BEFORE THE NATIONAL GREEN TRIBUNAL
PRINCIPAL BENCH, NEW DELHI
Original Application No. 485/2023
Diwan Singh Applicant
Versus
State of Uttarakhand Respondent
Date of hearing: 16.07.2024
CORAM: HON'BLE MR. JUSTICE SUDHIR AGARWAL JUDICIAL MEMBER
HON'BLE DR. AFROZ AHMAD, EXPERT MEMBER
Applicant: Applicant in Person (through VC)
Respondents: Ms. Anjali Rajput, Advocate for State of Uttrakhand (through VC)
Mr. Mukesh Verma, Advocate for UKPCB (through VC)
Adv Atif Suhrawardy for the CPCB (through VC)
Mr. Alok Singh, Mr. Deepak Shukla and Ms. Ananya Singh,
Advocates for Project Proponent.
Mr. Shamshad, Adv, Amicus Curiae with. Mr. Arijit Sarkar and
Ms. Nabeela Jamil, Advocates.
ORDER
1. This Original Application was registered on a letter petition raising complaint that a tunnel, length 1.5 km, is being constructed by M/s Khutani Power Project (hereinafter referred to as 'Project Proponent/PP') in village Batgeri and Sirsauli, Tehsil Ganai Gangoli, Block Gangolihat, District Pithoragarh, (State of Uttarakhand). On account of the aforesaid work undertaken by PP, cracks have appeared in houses of residents of locality which is likely to cause damage to lives and property anytime.
2. Taking note of the said complaint, vide order dated 04.08.2023, this Tribunal constituted a Joint Committee comprising representative of Ministry of Environment, Forest and Climate Change (hereinafter referred to as 'MoEF&CC'), Integrated Regional Office, Dehradun, Uttarakhand, 1 Uttarakhand Environment Protection and Pollution Control Board (UEPPCB) and District Magistrate, Pithoragarh. The said Committee was directed to submit a factual Report on the subject.
3. Pursuant thereto, Joint Committee submitted its Report by e-mail dated 18.11.2023. Report said that it could not be ascertained that cracks in some residential buildings in villages have occurred due to any activity of Project Proponent. However, Committee recommended that for finding out reasons of development of cracks, matter may be required to be examined by some subject expert institutes.
4. Consequently, vide order dated 30.01.2024, Tribunal constituted another Expert Committee comprising (i) Director of Wadia Institute of Himalayan Geology, Dehradun, (ii) Director of Institute of Seismological Research, Gandhinagar, (iii) Central Pollution Control Board (iv) Regional Officer, Ministry of Environment, Forests and Climate Change, Dehradun and (v) Collector, Pithoragarh.
5. The said Committee submitted Report dated 19.04.2024, and its observations are as under:
"Based on the field visit, observations and available information, the Joint Committee submitted the following:
Looking into all the aspects, past reports and on-site inspection, the causes of the development of cracks in the houses at both villages can be summarized as below:
a) The houses are mostly constructed over colluvial deposit without concrete base slab as such the weight of the overburden (i.e. of the houses) must have distributed un-evenly that resulted in the development of cracks and bulging of the walls.
b) The houses are constructed using small rock slabs without cementing materials, only the outer sides of the walls have been plastered either by cement and sand, or locally available materials (mixtures of mud and twigs and cow dungs). The roof slabs are constructed over the top of loosely 2 placed small slabs along with that of the roof slab have resulted in redistribution of the overburden weight that led to the development of cracks and bulging of the walls in the houses.
c) Based on the field observations and information collected, it can be concluded that at present cracks observed in the houses of the villages Batgeri and Sirsauli's are due to local construction practices, materials used and local site conditions. These are not developed due to works carried out by M/s. Khutani Power Company Ltd. (no.5 at the project construction site).
d) A site specific seismic study may be carried out for the project by institute of repute. The design calculations of various structures shall be based on seismic coefficient arrived at from such study.
e) The boundary wall height needs to be enhanced to about
6.0 ft, toward River Saryu to avoid the spillage of debris from much dump site no.2.
f) Should submit the action plan to local concern authorities for stabilization of all muck dump site appropriately & concern authority required to review the same periodically and verify the compliance.
g) The debris excavated or any disposable material should not be discharged/disposed on the back of River Saryu or at any non-identified places. It must be disposed of as per conditions laid down in the Consent to Establish (CTE). The SPCH must periodically monitor and ensure strict compliance of the CTE issued."
6. While going through the above Report we found that in respect of seismic studies, observations of Expert Committee are as under:
"A report on structural design calculation for tunnel intake prepared by M/s Tata Consulting Engineers Limited is also shared with the committee. The report was reviewed in detail. It was found that M/s Tata has wrongly considered the project in Zone IV as per seismic zoning map of India published by BIS. Actually, the project site is located in Zone V. Considering the available documents, it seems the site specific seismic studies were not carried out for the project. The calculations are based on seismic zone factor only. The recommended horizontal seismic coefficient as per Zone V is 0.24 as per National Committee on 3 Seismic Design Parameters (NCSDP) while M/s Tata has considered 0.11 factor for calculations."
7. Respondent 5 has filed its reply dated 14.05.2024 and on the aspect of above observations made by Expert Committee, it has submitted its own Expert's Explanation as under:
"A report on structural design calculation for tunnel intake prepared by M/s Tata Consulting Engineers Limited is also shared with committee. The report was reviewed in detail. It was found that M/s Tata has wrongly taken the project in Zone IV as per seismic zoning map of India published by BIS. Actually, the project site is located in Zone V. Also, it seems that site specific seismic studies were not carried out for the project. The calculations are based on seismic zone factor only. The recommended horizontal seismic coefficient as per Zone V is 0.24 as per National Committee on Seismic Design Parameters (NCSDP) while M/s Tata has considered 0.11 for calculations.
TCE's Reply Khutani Small Hydro Electric Project is being developed as a low- head 'Run-of-the-River' type development involving a diversion barrage across the Saraju River in the Bageshwar district located in the Kumaon region of Uttarakhand. The project lies in Zone V as per the Seismic Zoning Map of India incorporated in IS: 1893 (Part-1)-2016
.
The design horizontal seismic coefficient (ah) for project components are calculated according to Indian Standard IS 1893-1984 criteria for earthquake resistant design of structures and as given below as per seismic coefficient method given in clause 3.4.2.3. of IS 1893- 1984 as=β*1* a0.
Where, β = coefficient depending upon the soil foundation system I = factor depending upon the importance of the structure αo = basic horizontal seismic coefficient For Barrage β = 1 (Refer Table 3) I = 3 (Refer Table 4) αo = 0.08 (Refer Table 2 for Zone V) 4 Therefore, design horizontal seismic coefficient (αh) = 1 x 3 x 0.08 = 0.24 This is in line with the recommended value as per zone V as per National Committee on Seismic Design Parameters (NCSDP) considering highest value of importance factor.
Therefore, Vertical seismic coefficient for barrage, αv = 2/3 αh = 0.16 Similarly, for Tunnel Intake Importance factor 1 = 1 being categorised as 'other structure' as per Table 4 Therefore, Design horizontal seismic coefficient for tunnel intake(αh) = 1 x 1 x 0.08 = 0.08 However, In the structural design report for tunnel intake vide Doc. No.: TCE 7784A-CV-CALC-3028-01 (R2), the Seismic Coefficient (ah) was calculated as 0.11 following the formula αh = z/2*I/R* Sa/g provided in IS 1893 (Part-1)-2016.
It is pertinent to mention that IS: 1893 (Part-1)-2016 deals primarily of building structure and the provision indicated in the above code for calculating design seismic coefficient is meant for buildings.
For hydropower structure, mainly dam/barrage/intake, horizontal seismic coefficients are generally calculated as per provision given in clause 3.4.2 3 of IS 1893-1984.
Therefore, the method for calculating design horizontal seismic coefficient following IS:1893 (Part-1)-2016 and seismic zone were wrongly adopted in the structural design report for tunnel intake.
However, the value calculated in the report (0.11) is more than the actual value (0.08) calculated following IS 1893- 1984 and thus, will not have any impact in the design aspect.
8. The matter was examined by us on 16.05.2024 when learned Amicus Curei, Sh. M.R Shamsad, Advocate stated that as per Expert Committee's report, in respect of seismic zone, there is an apparent error in as much as structural design for tunnel has been calculated by considering the seismic zone-IV though as a matter of fact, area falls in seismic zone-V and 5 therefore, value of seismic co-efficient value (denoted as 'ah')was computed as 0.11 though it would have been different computed by taking seismic zone as V.
9. In view thereof, we direct Expert Committee constituted by this Tribunal vide order 30.01.2024 to look into this aspect of the matter and submit report.
10. Pursuant to order dated 16.05.2024, Expert Joint Committee's report dated 11.07.2024 has been submitted.
11. Report shows that it has considered comments of Dr. Sumer Chopra, one of the members on Expert Joint Committee in reply submitted by project proponent (respondent 5) and his comments are as under:-
"Facts on the reply submitted to NGT on seismic parameter IS 1893 is the Indian standard code of practice for "Criteria for Earthquake Resistant Design of Structures." The code has undergone several revisions to incorporate advancements in knowledge and technology related to earthquake engineering. The IS 1893-1984 is the fourth revision while the IS 1893-2016 is the sixth revision.
As per the IS code, the horizontal seismic coefficient (ah) for a structure can be computed by two methods,
(i) Seismic coefficient method / Equivalent static method and
(ii) Response spectrum method.
The seismic coefficient method is a simplified approach for seismic analysis, often used for regular and low-rise structures. It approximates the effects of an earthquake by applying equivalent static horizontal forces to the structure.
The response spectrum method is a more refined and accurate approach for seismic analysis, suitable for all types of structures, especially irregular and high-rise buildings. It uses the structure's dynamic characteristics to estimate the seismic response.
In IS 1893-1984, the expressions for ah in seismic coefficient method and response spectrum method are different. In IS 1893-2016, 6 although the expression is same, design acceleration coefficient for different soil types, normalized with peak ground acceleration (Sa/g) is different corresponding to natural period (T) of structure. For example, as per IS 1893-1984, in seismic coefficient method the design value of horizontal seismic coefficient αβ*I*α0 (1) where 1= a factor, called importance factor, depends upon the importance of the structure β= a coefficient depending upon the soil-foundation system ao= basic horizontal seismic coefficient. This value is different for different seismic zones.
In response spectrum method, ah= β*I* F0* Sa/g (2) where Fo is the seismic zone factor and Sa/g is the average acceleration coefficient for appropriate natural period and damping of the structure.
As per IS 1893-2016, the horizontal seismic coefficient ah= (Z/2)*(I/R)*(Sa/g) (3) where Z= seismic zone factor and R is the response reduction factor. Sa/g is taken from the following:
For use in equivalent static method 7 For use in response spectrum method M/s Tata Consulting Engineers Limited in the structural design report for tunnel intake Doc. No. TCH.7784A-CV-CALC-3028-01 (R1), estimated the seismic coefficient (ah) following the response spectrum method given in IS 1893-2016. While calculation, M/s Tata Consulting Engineers Limited considered the seismic zone factor Z of seismic zone IV, that is 0.24, 1=1, R=1.5, Sa/g =1.358. Therefore αh=(0.24/2)*(1/1.5)*1.358=0.11.
Now, M/s Tata Consulting Engineers (TCE) Limited mentioned that the ah value calculated using equation (1) above i.e. ah= 13*I* ao, that is using seismic coefficient method as per IS 1893-1984, is 0.08. They estimated the value by taking Importance factor 1=1, 3=1 and basic horizontal seismic coefficient for zone V (a0)=0.08. They mentioned that ah = 0.11, calculated in the report, is more than the ah value calculated by use of seismic coefficient method of IS 1893-1984. Therefore, it will not have any impact in the design aspect.
It is observed that
1. The Khutani Small Hydro Electric Project site is in seismic zone-V and M/s Tata Consulting Engineers (TCE) Limited admitted this fact now. The zone factor Z in equation (3) is 0.36 for zone-V. Considering Sa/g=1.358 (corresponding to the natural period of the structure), 1=1.0 and R=1.5 values as considered by M/s Tata Consulting Engineers Limited makes ah = (0.36/2)*(1/1.5)*1.358 =0.16. So ah=0.11 is not correct for sites in zone-V, rather 0.16 is the correct value.8
2. M/s Tata Consulting Engineers Limited mentioned that IS 1893-2016 (Part 1) deals primarily of building structure and the provision indicated in the code for calculating design seismic coefficient is meant for buildings. For hydropower structure, mainly dam/barrage/intake, horizontal seismic coefficients are generally calculated as per provision given in clause 3.4.2.3 of IS 1983-1984. That makes the ah value 0.08 (equation 1), using the equivalent static method. It is important to mention here that 'Recommendations for earthquake resistant design of structures' was first published in 1962, and revised in 1966, 1970, 1975 and 1984. Further, in 2002, the Committee decided to present the provisions for different types of structures in separate parts, to keep abreast with rapid developments and extensive research carried out in earthquake-resistant design of various structures. Thus, IS 1893 was split into five parts. The other parts in the series are:
Part 1: General provisions and buildings Part 2: Liquid retaining tanks - Elevated and ground supported Part 3: Bridges and retaining walls Part 4: Industrial structures, including stack-like structures Part 5: Dams and embankments (to be formulated) However, it is mentioned in "Foreword" of IS 1893-2016 that this standard (Part 1) contains general provisions on earthquake hazard assessment applicable to all buildings and structures covered in Parts 2 to 5.
It is obvious that M/s Tata Consulting Engineers Limited is comparing a h value estimated from older and recent IS codes and that too estimated by two different methods. Comparing the seismic horizontal coefficients calculated using IS 18931984 and IS 1893-2016 reveals significant differences due to updates and improvements in the standards over the years. The following Table-1 presents an overview of the main differences in both the version of the codes.
Table 1: Comparison of factors used for calculation of ah in IS 1893-1984 and IS 1893-2016 Factor IS 1893-1984 IS 1893-2016 Seismic zone The seismic zones were Zones were updated, with factor (Z) categorized into five zones (I Zone V having a factor of to V) with corresponding 0.36.
zone factors. Zone V had the highest factor of 0.4.
9
Importance factor The importance factor More detailed importance
(I) ranged from 1.0 to 3.0 factors ranging from 1.0
depending on the type of to 1.5 or higher for critical
building. structures.
Response This factor was not explicitly More detailed and
detailed in the 1984 version specific to different
reduction as it is in the later versions. structural systems,
factor (R) ranging from 1.5 to 5.0 or
more.
Average To be considered for To be considered for
acceleration appropriate natural period rock/ stiff soil / soft soil
coefficient and damping of the sites based on
(Sa/g) structure appropriate natural
period of the structure
"
12. Joint Committee agreeing with the said comment, has recorded its summary findings as under:-
"Summary:
o The formula for ah is similar in concept for both the versions of the IS codes, but uses updated factors and response spectra, leading to different results. Hence, the seismic horizontal coefficients calculated using IS 1893-1984 and IS 1893-2016 are not directly comparable due to significant updates in seismic zoning, importance factors, response reduction factors, and response spectra.
o The 2016 version provides a more accurate and detailed approach reflecting current knowledge and practices in earthquake engineering. Consequently, calculations using the 2016 code will generally result in different, and often higher, seismic forces, ensuring improved safety and performance of structures under seismic events.
o Justifying the estimations with older provisions is not correct and there should be consistency in estimations.
o In view of the above, the ah value will be 0.16, considering 1=1.0, R=1.5, Sa/g= 1.358 and Z (for zone-V)=0.36."
13. Learned counsel appearing for respondent 5 stated at the bar today that they do not propose to file any objection to above report dated 11.07.2024 and on the other hand, respondent 5 (proponent) is agreeable to recompute structural design calculation in the light of report submitted 10 by Expert Joint Committee and take remedial and corrective measures accordingly in respect of designing and constructions in question.
14. In view thereof, we do not find any exigency to keep the matter pending further and dispose of this original application by directing respondent 5 to reconsider the structural design calculation in the light of Expert Joint Committee report dated 11.07.2024 and take necessary remedial and corrective measures for strengthening the constructions in dispute and take all steps for consequential safety measures within a period of three months and submit a compliance report with Registrar General of this Tribunal, who, if finds necessary, may place the matter before Tribunal for further orders.
15. With the above directions/observations, the original application is disposed of.
Sudhir Agarwal, JM Dr. Afroz Ahmad, EM July 16, 2024 Original Application No. 485/2023 AB 11