Interview: Keith Mandisodza – Geotechnical Engineer

This week on Inside Mining Zimbabwe I had the privilege of interviewing not only someone with a similar name as mine but someone who is making Zimbabwe proud with the outstanding work he has done back home, on the continent and now abroad.

Keith Mandisodza has years of multi-disciplinary experience in mining and civil geotechnics and mine engineering throughout Australia, Southern Africa, South America and Madagascar to his role as Principal Geotechnical Engineer for Cartledge Mining and Geotechnics. Keith’s proven expertise is in delivering operational support studies, technical reviews and audits, operational improvement through practical and innovative solutions, open cut and underground mine design and tailings monitoring and management. Previously, Keith Mandisodza has worked as a site operational geotechnical engineer and rock mechanics engineer at different levels, both underground and open-cut, in Zimbabwe, Zambia, Madagascar, Suriname and Australia.

What is the importance of a mine geotechnical Engineer, how does continuous geotechnical data collection and analysis of importance to mines in Zimbabwe?

A geotechnical engineer is an integral part of the mine technical services, which is usually a department that is responsible for strategic mine planning and effective technical guidance of mining operations. The main role of geotechnical engineers in this integrated functional group is, to provide timely advice to management and operational teams regarding rock or soil mass responses to excavation; to provide ground engineering support to achieve mine production targets, and to identify opportunities to improve geotechnical aspects of the mine design. These multi-faceted functional roles require enough data collection to be able to provide adequate geotechnical recommendations as per the code of ethics and engineering judgement. Continued data collection allows for improvements in supporting models that can always be inferred for guidance when making important decisions for operations. Hence, allowing for more optimisation and effective implementation of risk management instruments to prevent and mitigate against unwanted events through critical controls.

How does geotechnical data collection of significance in mine design?

The cornerstone of any practical geotechnical analysis and design work is the database upon which the definition of input material properties is defined. Even the most sophisticated analysis can become a meaningless exercise if the geotechnical information upon which it is based is inadequate or inaccurate. Hence, data collection plays a significant part in design optimisation.

Geotechnical Engineers rose to popularity around the 2000s, how have they done the world over to reduce mine accidents and improve efficiency?

Point of correction, geotechnical engineers have been around since the 1920s. In Zimbabwe, because we didn’t have geotechnical engineering courses at universities (and still don’t), it has taken long to have such a career path for many, because it is not a commonly talked about field to be considered as a career path at schools and universities. Many of us had to go through other alternative courses to practice as geotechnical engineers. Back in the day geotechnical engineers were “godfathered” in the industry after a geology degree, mining degree, or a civil engineering degree. Some had to pursue a postgraduate degree in geotechnical engineering to practice as a geotechnical engineer. However, this has since changed through the years and geotechnical engineering undergraduate degrees are now being offered at universities worldwide, and still to be introduced at Zimbabwean universities. My geotechnical career path has been through a geology degree, which I completed at the University of Zimbabwe, and then pursued a postgraduate degree in Geotechnics, in the United States.

Regarding the second part of the question, I may not be able to quantitatively give a statistical representation of how geotechnical engineers have done to reduce mine accidents but, since the turn of the 20^th century, there is now a better understanding of the geological setup of most work environments which results in calculated risk frameworks formulation based on the knowledge accumulation, to manage geotechnical risks subsequently improving the general health, safety and environment of respective work areas. Since the turn of the decade, global technological advancements have played a critical role in the improved management of geotechnical hazards through more advanced approaches to numerically model the variability and complex geological conditions which play a critical role in geotechnical designs.

How important is risk management to geotechnical engineers, can the Zimbabwe mining sector benefit from geotechnical Engineering, and to what extent?

Risk management involves the coordination of activities to direct and control an organisation with regard to risk. In the mining (and/or civil) sector(s), geotechnical risks are often associated with an operational function to health and safety considerations as well as economic considerations for projects. It is fundamental, as geotechnical engineers, to have risk‐management skills, validated through detailed assessments of geotechnical risks to projects.

The use of modern technology in geotechnical Engineering is of importance, is the country ready to adapt to an updated mine planning software because the world is heading towards 5G network, yet we are yet to use 4G?

Yes. In fact, most mines will probably have more advanced network systems relative to most areas due to the requirement of such robust network systems, which enable operations and processing efficiency. However, regardless of the mining network requirements, the government should be setting up strategic infrastructure enabling the country to embrace technological advancement and harness its unlimited potential to systems improvements in general.

What is the significance of developing and implementing a site-specific Ground Control Management Plan in geotechnical engineering, how does modern mining gain from this? Can Small scale miners try to implement this at a small scale of course?

A geotechnical Ground Control Management Plan or GCMP, as it is known in the industry, is the main governing document for risk management of geotechnical critical controls. It is the main operational document that outlines; the regulatory framework for practice; site physical location setting and controlling factors; mine design and operation process; legal appointments, accountabilities and responsibilities of all stakeholders; risk profiling and risk management of operations; geotechnical processes considered to manage risks; mine design verification processes; quality control and quality assessments (QAQC) processes; review and audit processes. It is based on an observational method criterion where systems can be established, implemented, monitored, reviewed, and reused in that cyclic fashion.

How feasible is the statement, “to seek continuous improvement of the initial mine design to safety increase mine value and derisk long term production profile?

During the early stages of mine designing and project development, data availability is limited meaning, the reliability of the design models is low. Thus, there is a need for continuous data collection and processing to feed into these models and improve reliability. In so doing, improved designs in terms of safety and economic mine value can be implemented, reducing associated safety and productivity risks.

What is the impact of detailed geotechnical design on pit mining economics?

In most cases, the value of open-pit mining is driven by the ore to waste ratio, which subsequently determines the strip ratio. The lower the strip ratio, the higher the return for the operation and vice-versa. Slope designing through the determination of the optimum slope angle that meets both economic and safety criteria is a critical function of the geotechnical engineers. This process is achieved through the collection of relevant site geological parameters and application of rock or soil mechanics principles. It is this critical function of the geotechnical engineers to provide design parameters that produce the most value for the excavation that is reflected through the mining economics.

How does a detailed geotechnical design of importance on an underground mine?

In underground operations, optimisation of the mine infrastructure and mining method is a key metric that determines the ore extraction per meter development. Optimisation of the ground support demands relative to excavation profiles, rock mass parameters, geological structure, stress and seismicity is also critical. These importance metrics are determined by geotechnical engineers. A good design that considers all the relevant input parameters in the feasibility study of a mine site will also determine the economic values of that mine operations. Thus, geotechnical engineers play a major role in the early stages of mine design and planning.

How does a geotechnical Engineer solve the impacts of geological factors on a mine, both underground and open-pit?

A good geotechnical engineer should have a sound geological background, in both theoretical and practical aspects, to be able to deal with most issues that affect mine operations. Considering that most mines are located in geologically complex areas, it is pertinent for the geotechnical engineer to familiarise themselves with the underlying geological controls that led to the formation of the orebody on a regional and local scale, and be able to determine optimised designs and ground support requirements. Failure to preconceive the importance of underlying geological conditions lead to under-designing or over-designing, leading to safety and economic connotations.

If you meet the Mines Minister Hon Winston Chitando what five things will you advise him on Zim mining.

Through my diverse experiences in different continents, mining methods and mining governance systems, the five most important things I can advise the mines minister are,

Implementation of effective policies that allow for investors to invest in Zimbabwe
Attractive mining policies that bring employment opportunities to the locals and improve the economic situation of the country
Belief in our own people, especially those qualified and experienced in the field, and give them relevant opportunities to implement change through embracing technology and innovation
Setup of transparent systems that account for mineral exploitation and trade. Zimbabwe is known to be a mineral wealth country, yet we struggle to account for this mineral wealth in our economic systems and policies, this must change.
Put tighter legal frameworks to streamline the exploitation of minerals rights systematically and thus, filter away all illegal avenues through which accountability is failing currently and replace these with more robust and dynamic systems that support accountability.

What can Zimbabwe do differently to attract foreign investment?

I think to reiterate what I have highlighted above, setting up systems that attract investors will be a key factor in bringing back that lucrative attraction to the investor community. I have been in situations where companies have been looking for countries to invest and expand their respective portfolios and it’s quite unfortunate that they don’t find most African countries meeting all the key criteria that often provides that business attractiveness, mainly due to a bad reputation that has been ingrained in the way most African countries do business in general. Now, because the grain has been forged and set in that specific orientation going against the grain will result in those interested companies getting some “business splinters”, which many are not comfortable with. Hence, for Zimbabwe to be different from this outlook, it has to set up systems that counteract positively the current perception set by many African countries. This won’t be an easy feat but very achievable, and will definitely set the country as a beacon of hope for many to follow. Despite the volatility associated with doing business in the African continent, that many investors are not willing to take aboard, I do feel that the future of the mining industry is in Africa. Thus, in light of this perspective, it’s only prudent for a country to position itself strategically to be able to benefit, and take advantage of its very own potential.

What motivated you to move from geology to Geotech?

In my opinion, and I guess in many others too, geology sets a solid foundation for one to be a good geotechnical engineer. Considering that, when I started studying geology, physics, and mathematics at the University of Zimbabwe, I didn’t know what I was getting myself into. But, because I had a strong passion to understand how things work, I grew into the science and it also grew into me. Graduating with a degree in geology and physics opened an opportunity for me to work as a geologist at Shabanie mine, and it was at this mine that I was moulded into first, a rock mechanics geologist, and later a rock mechanics engineer. It took me five years to transition from underground mining, practising as a rock mechanics engineer, to open-pit mining, when I moved to Zambia, to become a geotechnical engineer. I don’t think there was any motivation to switch from being a geologist to geotechnical engineer, I am still an ardent geologist at heart and will always be. I guess for me, I evolved or transitioned into geotechnical engineering. However, the only difference I can pick between the two is, geology is a science and geotechnical engineering is a speciality branch of civil engineering that deals with earth materials and is primarily concerned with defining, understanding, and utilising through design the engineering characteristics and properties of these earth materials. On the other hand, geology is an observationally-based science employing not only the myriad of geologic principles but mathematics, chemistry, physics, and biology as tools to characterize the geologic conditions, so they are made for each other, hand-in-glove I would say.

How can mine geotechnical Engineers be incorporated into the small-scale mining sector?

Considering the hazard profile that is associated with small-scale mining, the incorporation of geotechnical engineers is critically essential and will need to be considered by relevant authorities. This will enable the effective management of risks associated with small-scale mining. However, a caveat with such a proposal for mining to proceed with intent to risk abate is the requirement for adequate ground reinforcement or support that will add unwelcome cost to the “mining process”, which might be unfavourable for many small-scale miners.

Do you ever see yourself working in the Zim mining industry?

Absolutely! Though, there are conditions to that emphatic assertion. First, my family has to be willing to relocate from down under, something that has sort of become a norm for us, having relocated to many continents and countries alike. Also, the reason for relocation has to outweigh all the other counteracting assumptions that are currently there for us as a family. But, if there is one reason I would relocate all things being fair, it will be to bring back home the knowledge I have accumulated in foreign lands, to mentor others, and use that knowledge for the betterment of Zimbabwe. Now in saying that, there are a lot of dots that have to line up from an economic perspective in Zimbabwe, as well as policies and how this knowledge can be harnessed and effectively channelled to improve the systems. Many have already trodden that path before me and the results don’t convince me yet, so we will see.

Words to a Tsitsi who is currently studying to be a Geotech like you?

It’s good to see young girls not only pursue STEM subjects but excel. I am an avid supporter of the girl child and would like Tsitsi to know that she has chosen a great career path. It’s also good to see that you can now get career guidance in the geotechnical space, which many of us never had the chance, and had to learn along the way. Continue learning more and research more about the diversity of geotechnical engineering. Keep abreast with technological advancement, as it will continue to play a significant role in geotechnical engineering space. Get a mentor to guide you on which branch of geotechnical engineering to take, as there are many. If you decide to follow the mining geotechnics, that will be a great choice, though it will come with a lot of challenges, many of which are learning curves both in your career and life in general. The important thing is to stay true to your passion!

Family life (wife kids)?

Keith Mandisodza is married to a lovely, childhood sweetheart and we have been blessed with three adorable girls.

Besides work what do you enjoy doing in your spare time?

Outside work, Keith Mandisodza enjoys spending time with family and travelling the world. I enjoy watching football especially when United play. I also play soccer will fellow Zimbos in the league in Brisbane. I used to play cricket during my school days but now I enjoy watching it. Outside sport, I enjoy a good read on topics ranging from leadership to science and technology. I have also recently started wine and whiskey collecting, which is quite interesting, especially finding those vintage ones.

This article first appeared in the Mining Newsweek copy of 11 May 2020.