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PRAVIN KOLHE,

(Mobile No. 8806999777)

Superintending Engineer, Water Resources Department, Government of Maharashtra

About Temghar Dam

Leakages & reasons

Remedial Measures

Short Term – Grouting / Shotcrete

Long Term – Concrete Backing

Learnings

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4 Temghar Dam

Mutha River (Krishna Basin)

• 40km from Pune

• Purpose: Drinking + 1K ICA

• Capacity =3.71 TMC (105Mm3)L=1075m

H=86mConstruction Year = 1997 to 2001

27 Monoliths, Central Spillway = 72m

Dam Foot PH = 4MW

L section of Temghar Dam

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Tender I

M. No. 1 to 13

Tender II

M. No. 14 to 17Tender III

M. No. 18 to 27

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The reduction in leakage in the year 2012 was observed due to the grouting carried out in the year 2011.

From 2013 again leakage increased year by year and reached to 2587 LPS in 2016

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Leakage

in LPS

Year

508 526 602

307 402 415

1174

2587

0

500

1000

1500

2000

2500

3000

2009 2010 2011 2012 2013 2014 2015 2016

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Temghar Dam Expert Committee (TDEC) Chairmanship of Shri. V.M.Ranade (Retired Secretary)

Formation 27/8/2014

Scope: to study the problem of seepage from the dam and to recommend remedial measures to minimize it and to ensure safety of the dam.

Proposed Remedial measures Short Term remedial measures

Long Term remedial measures

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Grouting

VPD Cleaning

Curtain Grouting in Foundation

Monolith Joint Treatment

Shotcrete to U/S Surface

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D/S Concrete Backing

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13

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Dam Top to IG

IG to FG

U/S Face

D/S Face

3 Stages:

-Primary

-Secondary

-Tertiary

Drilling Holes as per Grouting Pattern

Water Intake Test

Grout Mix Design -Empirical

Double Drum Mixer – Colloidal State

Apply Grout

Tests & Records

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• Proportion of Ingredients:

Cement, Flyash, Silica,

Admixtures, water

• Mixing procedure to get a

colloidal mix

• QC Tests Norms &

Frequency

Cement: Fly

Ash: SilicaW/C Ratio

Admixture (% by wt. of

cementatious material)

Avg. Comp.

Strength

(Kg/cm2)

Density

gm/cc

Marsh

Cone Time

(sec)

Settle

ment

Pow

der

Sup

er

pla

stic

izer

Acc

ele

rato

r

7 d

ays

28

days

80:18:2 0.65 2%5 ml per kg of

cementatious material107 222 1.8 27 to 36

Less

than

5%

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Sr. No. Test

Results More than Frequency

As per CWPRS

guidance

As per

observations at siteAs per EM 1110-2-3506 As per actual at site

1Marsh Cone Test

(Flowability) 27 to 36 sec 28 to 35 Once per day

One per every 2 hrs per

mixer

2Settlement Test

(Colloidal State)< 5% 2 to 3 % Once per week

One per every 2 hrs per

mixer

3pH

(Alkaline)11 to 13 11 to13 --

One per every 2 hrs per

mixer

4 Compressive Strength 222 kg/cm2 More than 250

kg/cm2

At the time of mix

designOne per day per mixer

5 Density 1.8 gm/ccMore than 1.8

gm/cc

--One per day per mixer

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18

19

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Chiselling & Surface Cleaning

Fixing Wire Mesh & Anchors

Apply 1st

Layer 50 mm

Apply 2nd

Layer 50 mm

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Sr.

No.

Test Pannel / Mold size Method of filling Frequency Range

1 Slump -- As per standard practice Per batch Less than or

equal to 100mm

2 Crushing strength 100mm x100mm

x100mm

Manually with tamping Per batch 7days ≥ 60 kg/cm2

28 days ≥100kg/cm2

45 to 90 days ≥ 150kg/cm2

3 Core test pannel 600x600x150 By Nozzle Per Monolith

4 Early Strength, Partial-beam

Compression Test

150x100x100 Manually with tamping Per Monolith vary in the range 2.5 kg/cm2 to

25 kg/cm2

5 Split Tensile Strength

Test

150x300 By Nozzle Per Monolith 10% of the Crushing Strength

6 Permeability Test 150X100 Manually with tamping Per Monolith coefficeint of permeability should

be less then 2.5 x 10 -8 mm/s

7 Bond test 150X100 Manually with tamping Per Monolith

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0.00100.00200.00300.00400.00500.00600.00700.00800.00900.00

1000.001100.001200.001300.001400.001500.001600.001700.001800.001900.002000.002100.002200.002300.002400.002500.002600.002700.002800.00

668 670 672 674 676 678 680 682 684 686 688 690 692 694 696 698 700 702 704 706 708 710

Leakage2016

Leakage2017

Leakage2018

2587

LPS

1039

LPS

413.8

LPS 265.8

LPS

Leaka

ge in

LPS

Water level in m

25

26

27

28

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श्री.हुद्दार एस.एन. सचिव (सेवाननवतृ्त), जलसपंदा ववभाग अध्यक्षश्री. रा. वा. पानसे सचिव (सेवाननवतृ्त), जलसपंदा ववभाग सदस्य

मखु्य अभभयंता(जस)ं,जलसपंदा ववभाग,पुणे सदस्यमखु्य अभभयंता (स्थापत्य), जलववद्युत प्रकल्प व गुणननयंत्रण, पुणे सदस्य

श्री.प्रमोद नारायण Director, DRIP, CWC सदस्यश्री. ई.स.िौधरी मखु्य अभभयंता (सेवाननवतृ्त), जलसपंदा ववभाग सदस्यश्री.ररझवान अली शास्त्रज्ञ – डी, कें द्रीय जल व ववद्युत अनुसधंान ससं्था, पुणे सदस्य

अधीक्षक अभभयंता, (धरण) मध्यवती सकंल्पचित्र सघंटना, नाभशक सदस्यअधीक्षक अभभयंता, धरण सरुक्षक्षतता सघंटना, नाभशक. सदस्य

श्री. स.ुवव. प्रदक्षक्षणे अधीक्षक अभभयंता, गोदावरी पाटबंधारे मडंळ, औरंगाबाद सदस्यअधीक्षक अभभयंता, पुणे पाटबंधारे प्रकल्प मडंळ, पुणे सदस्यकाययकारी अभभयंता, भामा आसखेड धरण ववभाग, पुणे सदस्य

सचिव

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अ) समितीची कार्यकक्षा To review the progress of leakage prevention remedial works and

strengthening of Temghar dam.

To take technical decisions regarding implementation of remedial work.

Assess efficacy of remedial measures.

Discuss the consultant monthly report and reports of quality control organization and suggest measures for improvements in quality of work.

Committee will meet twice a year if necessary it will meet more than 2 times in year as per necessity of work at site.

ब) कालावधी : धरणाचे गळती प्रततबंधक काि व िजबुतीकरणाचे काि पूणयहोईपर्तं.

झालेल्र्ा बैठका: ९ (प्रत्रे्की २ दिवस कालवधी)

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Mix Design for Grout & Specifications

Mix Design of Shotcrete and & Specifications

QC Tests and Norms

Practical approach for resolving technical issues

faced at site.

Density Tests

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WRD Monitoring by JE to CE level.

Guidance in Mix Design

Norms for QC Test

3rd Party QC Durocrete

Monitoring of activities independently

Guidance in Best Practices

Advanced Tests

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Potential Hazard is huge for dams

If quality compromised at construction stage, itcannot be restored.

Technical challenge to bring structure in safeconditions

Team work – PoE, CWPRS, QC, 3rd Party WC,Contractor and Field Staff (Integration of withinand Outside Dept experts)

PoE कार्यकक्षा – To Take Decisions

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IS/International Standards are not “िगडावरची रेष”. क्षेत्रीर्स्तरावरील गरजेनुसार तज्ञ संस्थेकडून R&D करून Grouting /Shotcrete चे Specifications modify करणे आवश्र्क

For Grouting, if mixer is kept at dam top and grouting iscarried out at dam foot, then pressure head developed in thepipe shall be taken into account.

Repair is not only technical matter: In case of Temghar it isAdmin, Financial, Legal, Disciplinary & criminal matter.

Face Media and try to bring good side in public

Moral Support of highest authorities including Secretary, ED,CE is most crucial.

PRAVIN KOLHE, Superintending Engineer, Water Resources Department, Government of Maharashtra

email: pravinkolhe82@gmail.com Mob: +91-8806 999 77736