MULEMBO & LELYA HPP 7/230 INV R... · ALTERNATIVE POWER HOUSE MANDATORY OPTION that illustrates the investigation envisaged for ... sl_D 01 179'206 8'471'193 179'127 8'471'124 120

February 2020

fEB

2020

Mulembo Lelya Hydro Electric

Power Limited (MLHEP)

MULEMBO & LELYA HPP

Phase 2 - FEASIBILITY STUDY

2 3A

0 I N V R S P 0 0 4 consulting engineers

studio pietrangeli

GEOPHYSICAL INVESTIGATION

WORK REQUIREMENTS

Client:

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MULEMBO – LELYA HPP GEOPHYSICAL INV WORKS REQUIREMENTS page i of i INVESTIGATIONS

230 R SP 004 Geophysical Inv. Work Requirements February 2020 studio pietrangeli, rome

INDEX

1 PROJECT OVERVIEW ........................................................................................................................ 1

1.a - GENERAL..................................................................................................................................... 1

1.b – PROJECT LAYOUT ....................................................................................................................... 1

1.c - GEOLOGY .................................................................................................................................... 2

1.d – SUMMARY OF THE CURRENT GEOTECHNICAL INVESTIGATIONS ................................................... 4

1.e – TIMING ...................................................................................................................................... 6

1.f – REPORTING ................................................................................................................................. 6

2 LOCATION and ACCESS ROADS ........................................................................................................ 8

3 TEMPORARY CAMPS ....................................................................................................................... 14

4 GEOPHYSICS.................................................................................................................................. 15

4.a – LOCATION and LENGTHS .......................................................................................................... 15

4.b – STAFF AND EQUIPMENT ............................................................................................................ 18

4.c – TEST OPERATIONS .................................................................................................................... 18

4.d – DOCUMENTS ............................................................................................................................ 19

4.d – REPORT OF THE SEISMIC INVESTIGATION PLAN ....................................................................... 20

Annexes Drawings

• INV D SP 015 Mulembo DAM, GEOPHYSICAL INVESTIGATION - Plan 1.5k

• INV D SP 016 Lelya WEIR, GEOPHYSICAL INVESTIGATION - Plan 3k

• INV D SP 017 Lelya-Mulembo TUNNEL & CANAL, GEOPHYSICAL INVESTIGATION - Plan 10k

• INV D SP 018 Mulembo WEIR, GEOPHYSICAL INVESTIGATION - Plan 2k

• INV D SP 019 Mulembo PENSTOCK & PH, GEOPHYSICAL INVESTIGATION - Plan 8k

• INV D SP 020 Mulembo ALT PH (mandatory option) PENSTOCK & PH, GEOPHYSICAL INVESTIGATION - Plan 8k

MULEMBO-LELYA HPP GEOPHYSICAL INV WORKS REQUIREMENTS page 1 of 20 INVESTIGATIONS


1 PROJECT OVERVIEW

1.a - GENERAL

This document illustrates the technical specifications of the geotechnical investigations (in situ tests and

laboratory tests) to be carried out in the Mulembo-Lelya HPP area.

This document comprises of the following sections:

1. PROJECT OVERVIEW, which gives a quick description of the project 2. LOCATIONS and ACCESS ROADS in the work area, including a description of the access roads to the

dam sites;

3. GEOPHYSISCS investigations which gives a description and the methodology for the seismic

investigations foreseen.

4. TEMPORARY CAMPS, showing some possible location for the establishment of the temporary camp,

5. TRENCHES and PITS, including their locations and relative technical specifications,

6. ALTERNATIVE POWER HOUSE MANDATORY OPTION that illustrates the investigation envisaged for

the alterative power house,

1.b – PROJECT LAYOUT

The Mulembo-Lelya hydroelectric scheme is conceived to exploit the potential of two rivers, Mulembo and

Lelya, while they run close before converging. These rivers stretch a steep slope, about 10 km long, which

creates a total head of about 450 m, available for hydropower uses.

The plant exploits the hydropower potential of the two rivers in the stretches between elevations: • 1010 m a.s.l. Full Supply Level of Lelya dam

• 570 m a.s.l. Tailwater level of Mulembo hpp

The main works of this layout are:

• a dam with a large reservoir (V = 330 Mm3) which regulates, annually, the flows of the Mulembo river,

• a small powerhouse at dam toe (No. 1 Francis, IP = 6 MW),

• a water transfer from the Lelya to the Mulembo rivers, including a small weir and a 5 km long waterway

including a tunnel and a canal, • a hydropower plant on the Mulembo river comprising a weir and:

o a 15 km long waterway, including a canal (L = 13 km) and a penstock (L = 2.5 km),

o an outdoor powerhouse, (No. 1 Pelton, IP = 100 MW).



1.c - GEOLOGY

The geological setting of Mulembo-Lelya HPP sites is characterized by an ancient (Precambrian) fold and thrust

belt characterized by intrusive granitic bodies and metamorphic belts (amphibolite facies).

Fig 1.1: General geology of the Mulembo HPP area (after Geological Map of Zambia scale 1:1’000’000)

The Figure 1.1 illustrates the general geology of the area including the following Mulembo-Lelya HPP project

components:

• Mulembo DAM,

• Lelya WEIR,

• Lelya weir to Mulembo weir water transfer features (TUNNEL and CANAL),

• Mulembo WEIR,

• Mulembo CANAL,

• PENSTOCK and POWER HOUSE.

The Mulembo Dam site is characterized by steep slopes (around 30 degrees) constituted of a cover of colluvium

(decimetric blocks) material covering a META-QUARTZITE bedrock outcropping at some location.

The valley section outlines a symmetrical shape as reported in the following figure.



Fig 1.2: Mulembo Dam site, view from upstream.

Moving downstream on the Lelya River the area of the Lelya Weir is characterized by a sound fine-grained

meta-granite foundation. In particular the meta-granite well outcrops nearby the river level.

Fig 1.3: Lelya weir site, view from downstream.

The Tunnel and the canal planned to transfer the water from Lelya River to the Mulembo Weir cross a ridge

mainly consisting of metagranite rocks.

Geophysical investigation are envisaged at the portals location and in correspondence of the limited rock

overburden.

At Mulembo Weir the foundation rock is newly a sound fine grained meta-granite rock well outcropping on the

right side of the Mulembo River (see fig. 1.4).

Fig 1.4: Mulembo Weir site, view from downstream.



The Mulembo Canal path is characterized by different geological setting which include stretches where the

rock is outcropping and stretches where the bedrock is from few decimetres deep. Where the rock outcrops

it consists of coarse grained to fine grained gneiss.

The penstock foundation is characterized by sub-outcropping metaquartzite relicts immersed in a thickness of

residual soil. Somewhere outcrops of metagranite have been found during the surface geology visit.

Fig 1.5: Mulembo Penstock and PH site, view from downstream.

At Power house location the META-PELITE (schist) outcrops at river level as shown in the following figures.

Fig 1.6: Mulembo Power House site.

1.d – SUMMARY OF THE CURRENT GEOTECHNICAL INVESTIGATIONS

The tables below summarize the quantities of the geophysical investigations envisaged in this assignment.



Tab 1.1: Summary of the geophysical investigations

The following table shows the quantities and the locations of the additional investigations for the alternative

power house (mandatory option).

SEISMIC LINE EAST NORTH EAST NORTH LENGTHname m m m m m

sl_D 01 179'206 8'471'193 179'127 8'471'124 120sl_D 02 179'116 8'471'115 179'036 8'471'046 120sl_D 03 179'263 8'471'203 179'146 8'471'101 180sl_D 04 179'138 8'471'094 179'021 8'470'993 180sl_D 05 179'251 8'471'152 179'172 8'471'084 120sl_D 06 179'161 8'471'074 179'082 8'471'006 120sl_D 07 179'145 8'471'203 179'252 8'471'090 120sl_D 08 179'109 8'471'171 179'215 8'471'059 180sl_D 09 179'075 8'471'142 179'181 8'471'029 180sl_D 10 179'035 8'471'107 179'141 8'470'995 120

TOTAL> 1440


sl_WL 01 190'403 8'459'721 190'112 8'459'509 360sl_WL 02 190'085 8'459'490 189'794 8'459'278 360sl_WL 03 190'228 8'459'668 190'299 8'459'571 120sl_WL 04 190'147 8'459'609 190'218 8'459'512 120sl_WL 05 189'969 8'459'479 190'040 8'459'382 120sl_WL 06 189'888 8'459'421 189'959 8'459'323 120

TOTAL> 1'200


sl_TC 01 189'774 8'459'798 189'664 8'459'749 120sl_TC 02 189'664 8'459'749 189'554 8'459'701 120sl_TC 03 189'695 8'459'828 189'743 8'459'719 120sl_TC 04 188'368 8'458'927 188'275 8'458'851 120sl_TC 05 188'275 8'458'851 188'182 8'458'774 120sl_TC 06 187'410 8'457'863 187'354 8'457'630 120sl_TC 07 187'382 8'457'747 187'354 8'457'630 120sl_TC 08 187'310 8'457'702 187'426 8'457'674 120

TOTAL> 960


sl_WM 01 186'325 8'457'356 186'262 8'457'254 120sl_WM 02 186'254 8'457'241 186'159 8'457'089 180sl_WM 03 186'233 8'457'322 186'335 8'457'259 120sl_WM 04 186'174 8'457'226 186'276 8'457'163 120sl_WM 05 186'141 8'457'174 186'243 8'457'111 120

TOTAL> 660


sl_PH 01 192'706 8'452'653 192'825 8'452'642 120sl_PH 02 192'825 8'452'642 192'945 8'452'632 120sl_PH 03 192'784 8'452'706 192'774 8'452'587 120sl_PH 04 192'902 8'452'696 192'892 8'452'577 120

TOTAL> 480

LELYA WEIR

MULEMBO WEIR

TUNNEL PORTALS

DAM

POWER HOUSE



Ta b 1.2: Summary of the geophysical investigations for the alternative PH (mandatory option)

All these activities will be carried out with the technical supervision of “the Engineer”, the consultant Studio

Pietrangeli (SP), on behalf of the Mulembo-Lelya Hydro Electric Power Limited (MLHEP). The contract will be

managed by the client (MLHEP).

This assignment includes all the activities necessary to complete these investigations such as mobilization,

transportation of the equipment, testing, processing of the data, interpretation and reporting.

This assignment includes also accurate topographic survey support (adopting WGS ’84, EGM 2008 reference

systems) during the investigations, locating the geophones.

1.e – TIMING

The total duration of the assignment is 8 weeks from the signature of the contract.

All the site investigations shall be completed, including the reports with all the results obtained, within 6

weeks from the signature of the contract.

1.f – REPORTING

All the results of the investigations shall be included within the investigations report which will include at least

the following sections:

GEOPHYSICAL INVESTIGATIONS

• detailed description of the activities, indicating deviations from the ToR, if any

• location including also maps to a 1:1000 scale with exact location of the lines, benchmarks coordinates

(with separated field logs of the topographical surveys carried out);• timing and personnel

• equipment and software

• International standards adopted

• description of the interpretative method adopted;


sl_PH_A1 01 192'361 8'451'711 192'465 8'451'650 120sl_PH_A1 02 192'465 8'451'650 192'568 8'451'590 120sl_PH_A1 03 192'454 8'451'725 192'394 8'451'622 120sl_PH_A1 04 192'556 8'451'666 192'496 8'451'562 120

TOTAL> 480

ALTERNATIVE POWER HOUSE



• illustration of the results obtained for each performed tests, described in the next sections, together

with correlations obtained from the analysis;

• raw data

The results from each geoseismic line shall be transmitted to the Engineer, for comments and review, during

the execution of the program. The format of these data will follow international standards, accepted by the

Engineer, in both digital and printed format.

The report will be submitted in DRAFT version to the Employer for comments and review. The Employer will

submit the draft report also to the beneficiary for comments and review.

Having received all the comments from the Employer and from the Beneficiary, the draft report shall be

upgraded and completed as requested submitting a final version of the report for the review of the Employer.



2 LOCATION and ACCESS ROADS

Mulembo-Lelya hpp is located between the Central Province and the Eastern Province of Zambia, along the

Mulembo and Lelya Rivers. The Lelya River flows into the Mulembo River at 640 m a.s.l and then it flows into

Lukasashi River, which is a tributary of the Lunsemfwa River.

The Mulembo and Lelya rivers originate both at about 1280 m a.s.l. and flow southwards before entering into

the Lukusashi River at approximately 520 m a.s.l. The Mulembo River has a total length of about 83 km while

Lelya’s length is about 38 km. The following table summarized the location of each project component.

Tab 2.1: Project components location.

The existing access roads to reach the main project components are outlined in the following drawings:

• 200 GEN D SP 001 A_EXISTING ACCESS ROADS, Plan 300k

• 200 GEN D SP 002 A_EXISTING ACCESS ROADS, Plan 110k

The accesses to the Mulembo Dam is possible both from the left and the right side along dirt roads and

footpaths:

• The right bank can be reached from Mkushi through the main road (T2 Road) connecting Lusaka to

Kasama. At Mkwamba (or Mpalasha) a secondary dirt road starts up to Nshinso village and after 3 km

a junction is encountered. After turning left and travelling for 26 km a family house is reached.

Fig. 2.1 Marketing centre at junction on T2 road with Mkwamba (or Mpalasha) – Nshinso dirt road

(2018).

Fig. 2.2 Junction 3 km after Nshinso; on the left the road bringing to Mulembo Dam right.

MULEMBO HPP COMPONENT E UTM WGS84 N UTM WGS84(name) (m) (m)

DAM 179 158 8 471 111LELYA WEIR 190 094 8 459 494MULEMBO WEIR 186 266 8 457 262POWER HOUSE 192 938 8 452 632



From here a footpath brings to Mulembo dam right site after 4.6 km (about 1h), it is mostly free from

trees, except on the slope located in the final part at site location (see Fig. below).

Fig. 2.3 Slope in the right bank of the Dam

• The left bank is reachable passing through Chibale village (55 km far from Mkwamba). From Chibale

a dirt road 33 km long brings at the beginning of the footpath (3.5 km, 40 minutes) that reaches the

left side of the Mulembo dam area. The footpath has similar characteristics to the right one (see fig

below).

Fig. 2.4 - Slope in the left bank of the Dam



• The access to the Lelya Weir is possible passing through Chibale village and continuing for 25 km up

to Mukopa village. From Mukopa after covering about 26 km (1h 30 min) the dirt road reaches the

Lelya weir area. A footpath of about 1.7 km has to be covered to reach in 30 minutes the Lelya River at weir location.

Fig. 2.5 Box culverts crossing the right tributary

river of the Mulembo river at Mulembo weir. Fig. 2.6 Mulembo weir site.

The area between the dirty road and Lelya weir is a flat to gentle sloping area, the following figure

illustrates a general view of the footpath.

Fig. 2.7 Aerial view of the footpath up to Lelya Weir

The following figure shows a picture taken during the site visit of 2018 along the foothpath, the area

is mainly covered by grass and few sparse small trees.



Fig. 3 – Picture of the foothpath up to Lelya Weir

• The Mulembo Weir can be reached from Mkushi through the main road (T2 Road) connecting Lusaka

to Kasama. At Mkwamba (or Mpalasha) a secondary dirt road starts towards South up to Mulembo

Weir (after 71 km, 3 hours) passing through Nshinso and Ngosa Villages.

Fig. 2.8 Box culverts crossing the right tributary

river of the Mulembo river at Mulembo weir. Fig. 2.9 Mulembo weir site.

Mulembo weir is easily accessible by 4WD car or truck, during our site visits, we have used as a

temporary camp Kumanga Mine, however the Contractor shall verify its availability or find another location. The following figure is an aerial view of the area with the indication of the dirty road.



Fig. 2.10– Aerial view of the Mulembo Weir area

• From here, it is possible to:

o Follow on foot the Mulembo Canal track

o Continue by car up to Kampilo River (6 km, 20 minutes) and reach the Penstock and Power

House areas covering a footpath which reach the Mkalata Mountain and steps down the

escarpment (5.7 km, 2 h 30 min).

Fig. 2.11 View of the Luano valley from Mkalata Mountain.

The accesses to Lelya-Mulembo water transfer features (Tunnel and Canal) have not been covered,

nevertheless the crossing points (on foot) have been detected on the two rivers (Lelya and Mulembo) in order

to follow the track both along the tunnel and the canal.

The Contractor shall evaluate carefully what is needed to transport the equipment to the site in order to

perform the investigations without any delay. The accesses to the site for boreholes and trenches may require a tracked drilling machine (or other

techniques) and excavator, and/or the execution of access paths. A site visit before the submission of the

proposals is highly recommended.

The following figure shows existing access roads to the Mulembo-Lelya project components.



Fig. 2.12 Mulembo HPP, existing access roads to the project components sites.



3 TEMPORARY CAMPS

The Contractor shall identify the most convenient location for the temporary camps, it is advisable having

more than one camp according to the planned investigations. Please find here below, as a preliminary

reference only, some indicative locations (to be confirmed by the Contractor) that we have considered in our

preliminary analysis (ref. dwg 200GENDSP001_002):

• Mulembo Dam - two camps might be established, if possible, one on the right and one on the left.

Fig. 4.1 – Possible location, to be confirmed, for the camps for Mulembo dam works

• Mulembo Weir – The camp might be established, if possible, at the Kumanga Mine. Its location is

reported in the following figure.

Fig. 4.2– One possible location, to be confirmed, for the camp for Mulembo weir works

• Lelya Weir - the camp might be placed, if possible, in the flat area between the main dirty road

and the weir location as illustrated in the following figure.

Fig. 4.3 – One possible location, to be confirmed, for the camp for Lelya weir works



4 GEOPHYSICS

We expect the seismic tomography to reach, normally, not less than 20m of depth. The effective depth reached will vary depending on the local geomechanical characteristics of the soil/rock foundations and we expect to be usually in a range from 20 to 40 m.

4.a – LOCATION and LENGTHS

The geophysical survey programs will basically include:

• Surface seismic tomography survey at the Mulembo HPP project components location:

o Mulembo dam site,

o Mulembo and Lelya weirs,

o tunnel portals (Lelya-Mulembo),

o Power House area.

The quantities of the tomographic seismic lines are indicated in the drawings: • 230 INV D SP 001 A - Mulembo DAM, Plan 1.5k

• 230 INV D SP 002 A - Lelya WEIR, Plan 3k

• 230 INV D SP 003 A - Lelya-Mulembo TUNNEL & CANAL, Plan 10k

• 230 INV D SP 004 A - Mulembo WEIR, Plan 2k

• 230 INV D SP 006 A - Mulembo PENSTOCK & PH, Plan 8k

Geophysical survey will be carried out in compliance with ASTM D5777-95 concerning refraction seismic.

A total length of 4’740 meters of refraction seismic lines have been envisaged and it will include:

• 1’440 m at Mulembo Dam

• 1’200 m at Lelya Weir

• 960 m at tunnel portal

• 660 m at Mulembo weir

• 480 m at Power house

The lengths and location of the seismic lines in the various Mulembo HPP project structures are summarized

in the following tables.



Tab 3.1: Mulembo Dam, seismic lines location and length.

Tab 3.2: Lelya weir, seismic lines location and length.

Tab 3.3: Mulembo-Lelya tunnel, seismic lines location and length.


sl_D 01 179'206 8'471'193 179'127 8'471'124 120sl_D 02 179'116 8'471'115 179'036 8'471'046 120sl_D 03 179'263 8'471'203 179'146 8'471'101 180sl_D 04 179'138 8'471'094 179'021 8'470'993 180sl_D 05 179'251 8'471'152 179'172 8'471'084 120sl_D 06 179'161 8'471'074 179'082 8'471'006 120sl_D 07 179'145 8'471'203 179'252 8'471'090 120sl_D 08 179'109 8'471'171 179'215 8'471'059 180sl_D 09 179'075 8'471'142 179'181 8'471'029 180sl_D 10 179'035 8'471'107 179'141 8'470'995 120

TOTAL> 1440

DAM


sl_WL 01 190'403 8'459'721 190'112 8'459'509 360sl_WL 02 190'085 8'459'490 189'794 8'459'278 360sl_WL 03 190'228 8'459'668 190'299 8'459'571 120sl_WL 04 190'147 8'459'609 190'218 8'459'512 120sl_WL 05 189'969 8'459'479 190'040 8'459'382 120sl_WL 06 189'888 8'459'421 189'959 8'459'323 120

TOTAL> 1'200

LELYA WEIR


sl_TC 01 189'774 8'459'798 189'664 8'459'749 120sl_TC 02 189'664 8'459'749 189'554 8'459'701 120sl_TC 03 189'695 8'459'828 189'743 8'459'719 120sl_TC 04 188'368 8'458'927 188'275 8'458'851 120sl_TC 05 188'275 8'458'851 188'182 8'458'774 120sl_TC 06 187'410 8'457'863 187'354 8'457'630 120sl_TC 07 187'382 8'457'747 187'354 8'457'630 120sl_TC 08 187'310 8'457'702 187'426 8'457'674 120

TOTAL> 960

TUNNEL PORTALS



Tab 3.4: Mulembo weir, seismic lines location and length.

Tab 3.5: Power House, seismic lines location and length.

It has to be noted that the location, type and the length of tests might be adjusted by the Engineer at site,

following also the results obtained from the first tests.

4.a.1 - ALTERNATIVE POWER HOUSE (MANDATORY OPTION)

We have identified another promising location for the Power House, therefore investigations will be extended

also to the alternative are, including:

• No. 4 seismic line (L = 480m) at the alternative powerhouse.

The following table shows the detailed quantities and the location of the additional investigations

ALTERNATIVE POWER HOUSE SEISMIC LINE EAST NORTH EAST NORTH LENGTH

name m m m m m

sl_PH_A1 01 192'361 8'451'711 192'465 8'451'650 120 sl_PH_A1 02 192'465 8'451'650 192'568 8'451'590 120 sl_PH_A1 03 192'454 8'451'725 192'394 8'451'622 120 sl_PH_A1 04 192'556 8'451'666 192'496 8'451'562 120

TOTAL> 480 Tab 5.6: – Location and length of the seismic lines at the alternative Power House

The position of the alternative power house together with the additional investigation is shown in the annexed

drawing:


sl_WM 01 186'325 8'457'356 186'262 8'457'254 120sl_WM 02 186'254 8'457'241 186'159 8'457'089 180sl_WM 03 186'233 8'457'322 186'335 8'457'259 120sl_WM 04 186'174 8'457'226 186'276 8'457'163 120sl_WM 05 186'141 8'457'174 186'243 8'457'111 120

TOTAL> 660

MULEMBO WEIR


sl_PH 01 192'706 8'452'653 192'825 8'452'642 120sl_PH 02 192'825 8'452'642 192'945 8'452'632 120sl_PH 03 192'784 8'452'706 192'774 8'452'587 120sl_PH 04 192'902 8'452'696 192'892 8'452'577 120

TOTAL> 480

POWER HOUSE



• 230 INV D SP 0020 A - Mulembo ALT PH (mandatory option) PENSTOCK & PH, GEOPHYSICAL

INVESTIGATION - Plan 8k.

4.b – STAFF AND EQUIPMENT

The survey will be carried out by teams including, at least, the following specialized workers:

• 1 Senior Geophysicist Supervisor

• 1 Geophysicist Surveyor

• 1 Surveyor

• 3 local workers

The senior geophysicist shall have at least ten years of experience in similar works, to be proved by means of

a CV with references upon request of the Engineer, while the surveyors shall have at least five years of specific

experience. Whether the qualifications of the personnel proposed might not be adequate, the Engineer might

request replacement at no additional cost for the Client.

The following (minimal) instruments and accessories will be sent by the Contractor to the survey site, including: • two 24-channel seismograph, operating in network as two single 24 ch seismographs or one 48 ch

seismograph, with seismic-impulse stacking capability, programmable analogical and digital filters

(high pass, band pass and band reject active filters), vertical signal gain (width) and sensitivity ranging between 6 and at least 92 decibels, digital data recording for further processing with at least 24-bit

output format;

• 48 vertical geophones with variable frequency ranging from 8 to 14 Hz;

• cable and accessories with the requested take-out spacing;

• energy source suitable to the depth of the investigation; it could consist of an hand operated hammer

(8kg), free-dropping weight, accelerated weight, or explosive charges (if allowed)

• spare geophones and cables.

• One RTK GPS System or a Total Station shall be used to identify the exact position of geophones and

shot point. • The software for data processing must work with the WET algorithm (License number must be

indicated in the bidding documents).

4.c – TEST OPERATIONS

The seismic data will be collected by the above seismographs with the following settings:

• The geophones interval is fixed at 5m.



• The shot "coverage" on the seismic layers shall enable a correct and detailed measurement of the

local velocity field down to the depths envisaged by the project or by the Consultant; however the

minimum coverage shall be of one shot every 3 geophones. • In case of profiles longer more than 240 m (48 geophones), to collect data continuously along the

same Seismic Line, the overlapping of shots for the two different part (i.e. for the first 240 m and for

the second part from 245 to 480m) shall be of 60 m, i.e. 4 shots for each part.

• Data processing shall be carried out after fixing the arrival times for each geophone and every shots.

• The tomographic approach shall be used by means of the WET algorithm with iterative reconstruction

of the finite element models. This approach shall enhance the presence of low velocity zones

interlayered between high velocity layers.

4.d – DOCUMENTS

For each investigation, the following documents are required: − General Information including:

job order, construction site, location, date

− Daily reports, including:

Team (Chief, Operator, Workers)

Daily production (Survey Site, Length of Seismic Lines Surveyed, notes)

Copy of the collected data (link to cloud used for storing or CD copies)

Topographical data set;

Survey photos − Processing activity including:

Processing sequence used;

Example of original and processed data files after filtering;

Editing the arrival times and check of anomalous data points;

Creating input files for WET processing

WET Processing

Tomography imagines editing criteria.

− Interpretation of the obtained results, including: Interpretation criteria;

Main finding:

Details of the main findings.

Suggested Follow-up.



4.d – REPORT OF THE SEISMIC INVESTIGATION PLAN

A report including the planimetric and altimetric location of the geophones of each array, with specific reference

to the key points or well-known cartographic elements of the area involved, should complete the seismic

investigation. Failing that, the abovementioned survey will include the relevant coordinates.

Survey and digital data logs should be also included.

Documents

MULEMBO & LELYA HPP 7/230 INV R... · ALTERNATIVE POWER HOUSE MANDATORY OPTION that illustrates the investigation envisaged for ... sl_D 01 179'206 8'471'193 179'127 8'471'124 120