Yohana Silas Malaki

 As an innovative geotechnical with over three years of experience in the mining and construction industries. I specialize in risk assessments, quantification and mitigation strategies. I have a solid understanding of engineering approaches and procedures in planning, design and control methods. I am also well familiar with the design of tunnel, slope, and subsurface structural. Furthermore, I am optimistic about the high-quality service, teamwork, and safety.

Position: Geotechnical Engineer

Employer: Pejuni Resource Limited-Kabanga Nickel Project

Year: January 2023-Present.

• Review of existing geotechnical investigation reports, re-logging of existing drill holes, and photo logging
• Applied rock mass characterization and classification systems in underground mining design
• Managed core box labeling, handling, core marking, orientation and photographing, logging, and sampling of core for mineral assays and geomechanics laboratory tests (AE sample, triaxial sample, and Brazilian test sample).
• Kinematics analysis of structures logged from oriented core for slopes and underground excavation stability analysis (Curved BH oriented core and Curved BH Tele viewer) by Dips7
• Conducting field permeability tests (falling head tests) for different drilled boreholes.
• Drill hole planning, deviation monitoring, and down-the-hole surveying by both reflex and gyro methods.
• Reporting on drilling and geotechnical logging on weekly and monthly basis.
• QA and QC of geotechnical data collected from Diamond drilling and geotechnical mapping.
• Data analysis and interpretation by 3D Numeric Model software (GEM4D and Leapfrog Geo).
• Database managements by using DH Logger software.
• Assisted with compiling geotechnical data, boring logs, supervision of trial pitting subsurface profiles resulting in accurate and efficient project delivery

Position: Engineering Geologist

Employer: Paulsam Geo-Engineering Limited

Year: May 2022-February 2023

• Coordinated with clients and prepared briefs as per the client's requirements and time frame.
• Working with Surpac and Leapfrog Geo in planning drill holes and making sections from the drilled and logged holes.
• Updating of geological maps, sections, prepared exploration monthly reports, and data storage management.
• Conducted detailed geological mapping and detailed core lithological and structural mapping in geological and geotechnical aspects.
• Structural logging from the core, outcrop mapping, and stereographic projection and kinematics analysis for slopes and underground excavation stability.
• Evaluated the work of all team members and prepared geotechnical reports for the project.
• Ensured compliance with all set standards and recommended changes if required.
• Carried out exploration works and interpreted different geological layouts and maps in figuring out the mode of mineralization of an ore body such as gold (Lupa Gold Field) and coal (Lumecha Basin-Songea).

Position: Geotechnical Engineer

Employer: Geounit Tanzania Limited

Project: Geotechnical investigation of the Founding soil for construction of transmission line from Kigoma- Nyakanazi

Year: December 2021-May 2022

• Coordinated with clients and prepared briefs as per the client's requirements and time frame. 
• Assessment of the geological risk of the project area and prepared a geological report for the site.
• Drill rig setup, site supervision, site risk assessments, and site management.
• Conducted field classification of the soil and rocks, supervised and led geotechnical drilling investigations,
• Explored and surveyed the construction site thoroughly, as well as performing various in-situ and laboratory tests on soil and rocks, such as the standard penetration test (SPT), to assess the suitability of the foundation.
• Used geological analysis of soil and rock boring to determine different layers at specific depths and used the result to provide recommendations for the team before construction.
• Design of shallow and deep foundations in weak soil and weathered rock
• Managed core box labeling, handling, photographing, and core logging.
• Supervision of the SPT test and sampling of disturbed, undisturbed, and SPT samples from the borehole investigation
• QA and QC management in drilling, SPT testing, sampling, sample preparation, and dispatch processes
• SPT and soil logging data analysis and presentation using Geostru Stratigrapher and Golden Strater.

Position: Geotechnical Engineer

Employer: Joint venture of Arab Contractors and Elsewedy Electric (JV-AC-EE)

Project: Julius Nyerere Hydropower Project (JHNPP)-2115 MW dam

Year: November 2020-December 2021

• Planned, coordinated, gathered, processed, analyzed, and interpreted data from core logging, field mapping, trial pits, in-situ testing, and laboratory testing.
• Used geological knowledge and expertise to characterize soil and rock mass and classify rock mass (RMR, Q, and GSI) for slopes, tunnels, foundation stability assessments, and remediation.
• Determined and documented the engineering properties of soil and rock at the work site.
• Inspected ongoing construction works and ensured compliance with all design standards.
• Performed the standard proctor compaction test, the unconfined compressive strength test on the cohesive test, soil properties, and classification.
• Conducted field and in-situ testing of soil (FDT, compaction test) and rock mass (lugeon test, in-situ rock strength test by Schmidt rebound hammer, field geological assessments).

Position: Engineering Geologist

Employer: Petra Diamond Limited - Williamson Diamond Limited

Year: July, 2020-November 2020

• RAB and RC drilling supervision, blast pattern design, and supervision.
• Data storage management and regular updating of different maps and sections.
• Solved geology and geotechnical-related issues at an open pit site using field mapping, stability assessments, and modeling techniques.
• Static and dynamic analysis of tailing dam slopes and pit wall slopes.
• Managed, supervised, and led geological mapping and geotechnical drilling investigations and sampling.
• Visual estimates of minerals in blast hole chip samples and Ensured commitment to adherence to QC/QA protocols for grade control and dynamic resource model input.
• Groundwater and seepage monitoring for tailing dam embankments and pit slopes.

Bachelor of Science in Engineering Geology (November 2016-July 2020): University of Dar es Salaam.