Ground improvement for stable ground

Q. What do you mean by ground improvement/modification and why we need it?

A. Ground improvement is the primary application of many geotechnical construction techniques. Poor ground conditions make traditional forms of construction expensive, thus it may be economically viable to attempt to improve the engineering properties of the ground before building on it. This can be done by reducing the pore water pressure, by reducing the volume of voids in the soil, or by adding stronger materials.

Q. If you would be more descriptive.....?

A. The existing soil at a construction site may not always be totally suitable for supporting structures.

For example, granular soil may be very loose and indicate large elastic settlement. So the soil needs to be densified to increase its unit weight and thus shear strength. Soft saturated clay layers are often encountered at shallow depths and that may not be suitable for construction purposes.

Hence, most of the times the top layer of the soil is removed and replaced with better soil.

Q. What are the methods available in the industry to address these issues?

A. If unsuitable soil conditions are encountered at a site, one of the following procedures may be adopted to ensure satisfactory performance of the structure:-

- Bypassing the unsuitable soil by means of suitable bearing material
- Redesigning the structure and its foundations for support by the poor soil
- Remove and replace the poor material with a suitable material
- Treating the soil in place to improve its properties

Q. Why does SOILTECH possess the required expertise in this field?

A. SOILTECH has extensive experience in a full range of geotechnical construction applications. This knowledge enables us to identify the most efficient approach to any sub-surface task and to quickly and safely achieve the project requirements while giving our customer complete satisfaction. We have undertaken not only modern day work but also some work related to ancient time.

Q. You mentioned that you have done some ground improvement work related to ancient history. Are you saying that these methods had been used in those times also?

A. Yes, absolutely! Let me take you through some examples. You must be familiar with Jetavanarama stupa which has a 28 ft deep foundation which sits on rock bed and most importantly; around the foundation, a brick work ring had been built to support the load taken by the soil.

Sometimes it was mentioned in ancient scripts that before building a structure on a particular soil, it had to be compacted properly using elephants to improve the strength and other properties. Therefore, it clearly says that even ancient people had considered the soil structure.

Q. Technically what sort of procedures would you take to improve the level of soil?

A. Normally these issues could be overcome by improving the shear strength of the soil, thus increasing the bearing capacity of shallow foundations or else by increasing the factor of safety of possible slope failure.

Q. What are the techniques available in the world to accomplish the above?

A. Cement grouting, chemical grouting, jet grouting, compaction grouting and fracture grouting are the most commonly available methods for ground improvement purposes.

For ground modification; Ground freezing, inserting micro piles, laying geo-textile layers, anchoring, soil nailing and laying geo grids and laying EPS blocks etc. are applicable.

Q. What are the methods available in SOILTECH?

A. Our company is facilitated with modern technological methods and equipment to take over every kind of ground improvement/modification matters which our customers bring to us. Our company is equipped with modern technology.

Q. What is it that you consider important when selecting a suitable method for ground improvement?

A. Before deciding a particular technique we first consider about the type of soil and its properties, type of structure and load distribution, material availability, local experience and preferences, economic considerations and most importantly the surrounding environment.

Q. Can you tell us about ground improvement/modification works that you have undertaken previously?

A. We have undertaken many ground improvement projects so far. In 2010 we carried out a project at the South Asia Gateway Terminals, Colombo. There, soil had eroded to the sea and considerable extent of the ground had sunk into the sea.

We grouted the whole affected area and uplifted it to the original position. Because of the successful completion of that work, our company won the ICTAD national award for ‘Innovative techniques in construction’ for the year 2011.

Apart from that we have improved settled grounds at four storeyed private building site in Malabe, five storeyed shopping mall in Kelaniya, seven storeyed hotel building in Nuwara Eliya, two petroleum tanks at Sapugaskanda etc. Most of the time we restored the settled grounds with an acceptable safety level which had previously been instructed to be abandoned.

Q. If a person brings you a problem regarding grou- nd modification, something which has not been dealt with so far, are you ready to accept it?

A. Of course! We are always willing to accept such challenges. Because, every technical matter always starts with a ‘known seed’. Being aware of basic concepts of soil mechanics and related other fields, each matter can be addressed accordingly. Since we have a very devoted staff with expertise in geotechnical disciplines, we are confident to accept any affair related to soil.

Q. What do you have to say to our readers?

A. We are proud to say that SOILTECH is experienced in ground improvement/modification works. If you have any issue regarding soil, you can contact us for faster and better results. Because, we must have probably solved a similar issue before and we are willing to keep your projects on stable ground.

Q. Ok. For more details how can we contact you?

A. You can contact us over the phone, by sending us an e. mail.

T.P. 0112 86 18 18
0722 236 000
e.mail [email protected]
Web www. soiltechltd.com