Climate change effect on stiffness behavior of Lateritic Soil Treated with Ordinary Portland Cement

Malaysia has used residual tropical soil (laterite soil) as a fill material for construction development. Besides that, about 25% of the total road network in Malaysia is unpaved roads whereby most of the unpaved roads use laterite soil as subgrade due to good engineering properties. However, the huge quantity of fine-grained particles in some lateritic soil exhibits poor engineering qualities and is considered problematic soil by engineers. Annually, several sections of the country have endured flooding and scorching weather. The occurrence caused extensive damage, particularly to the road structure. For example, during the dry season, the suction created has had a substantial impact on the permeability and shear strength of unsaturated soils. While flooding is a concern during this time period, designers should pay more attention to the understanding of the saturated situation. Shear strength, volume change, and compressibility parameters are used in geotechnical design. However, soil stiffness has been less considered, leading to a decrease in the lifespan of geotechnical infrastructure due to fatigue. This study is carried out in order to evaluate the influence of suction on soil stiffness at various strain levels during the wetting and drying cycles. The soil stabilisation method utilising Ordinary Portland Cement (OPC) is used to increase the strength of subgrade materials in order to meet the specifications for low-volume road materials. Based on the previous project (FRGS/1/2019/TK01/UTM/02/13) and using a modified oedometer with bender elements, a series of laboratory experiments will be performed using 6 per cent cement content dosages under unsaturated conditions. This study is expected to establish a relationship between the wetting and drying cycles that influence soil stiffness. This method of determining the soil stiffness of lateritic soil treated with OPC under cyclic soaking and drying is recommended as a subgrade material guideline for roads with low traffic volume.


Interested to join this work Please contact Muhammad Azril Hezmi- azril@utm.my

Fig. 1 Distribution of Residual Soil in Malaysia
Fig, 2 Cross section of Pavement and Railway tracks construction
Fig. 3 Stiffness measurement in construction
Fig. 4 Occurrence of unsaturated soil
Fig. 5 Initial Shear stiffness with suction

Call for Participant: COME & JOIN US in INFINID 2021!!!!

InFInID 2021

Call for Participant: COME & JOIN US in INFINID 2021!!!!
https://engineering.utm.my/civil/geochitra/

Participants are eligible for CPD & CCD points!_
BEM: 2 points
MBOT: 5 points
*CIDB: To be announced

Date: 21- 22 September 2021

Platform: Zoom (Online:link will be given)
Fee: USD30 only
Registration: https://engineering.utm.my/civil/geochitra/home/registration/

Dear Researchers / Academics / Practitioners,

Universiti Teknologi Malaysia (UTM) and Universitas Islam Sultan Agung (UNISSULA) organizers are proud to announce a collaboration with the geotechnical engineering, transportation, and coastal community and would like to welcome all of you to participate in InFInID 2021 which will be held from 21– 22 September 2021.
The conferences will be a premier platform for the presentation of new advances and research results in the fields of Civil Engineering (Geotechnics, Transportation & Highway, and Coastal Engineering). The conference will bring together leading researchers, engineers, and scientists in the materials and processes field of interest from around the world.

For any inquiries regarding the conference, please contact infinid@civil.my

We look forward to seeing you at InFInID 2021.

Sincerely,

InFInID 2021 Secretariat.
UTM: dzulaika@utm.my, Tel: +6010336 2021 (Dr. Dayang Zulaika )
UNISSULA: arisentani@unissula.ac.id, Tel: +6285740534997(Ms Ari Sentani) or +6285866888937 (Mr Niam); faiqun@unissula.ac.id

Geochitra 2021

In 2019 Department of Geotechnics and Transportation manages to organize a sucessful GEOCHITRA 2019. The conference managed to attract 200 participants and 8 exhibitors to the conference. The successful program has gained interest to UNISSULA, Indonesia invited us to collaborate organizing a similar conference in 2021.

Several meetings were held to ensure the coordination of the future conference could be achieved. The meeting was done through official visits and video conferences. Many ideas and suggestions were discussed to meet both agreements.

In Feb 2020, UTM had visited UNISSULA as a counter visit, this was our third official meeting. Besides the meeting, UNISSULA also introduces us to the Indonesian culture. Overall the visit was outstanding and very beneficial.

Official meeting
Visit to Old City of Semarang
Visit at Lawang Sewu
Dinner at CianJur Ikan Bakar
Visit to Kletong Sam Poo

Role of SWCC in Practice

Blight Lecture, – ISMCGE 2017 
Delwyn G. Fredlund, Senior Geotechnical Engineering Specialist, Golder Associates

Introduction

In Seoul 2017, Prof Fredlund one of top Unsaturated Researcher had delivered a talk in Soil Water Retention Curve in practice. The talk was delivered in Blight Lecture  in ISSMGE conference. Basically, Soil Water retention curve is the relationship between the water content, θ, and the soil water potential, ψ. This curve is characteristic for different types of soil, and is also called the soil moisture characteristic.

It is used to predict the soil water storage, water supply to the plants (field capacity) and soil aggregate stability. Due to the hysteretic effect of water filling and draining the pores, different wetting and drying curves may be distinguished.

The general features of a water retention curve can be seen in the figure, in which the volume water content, θ, is plotted against the matric potential, {\displaystyle \Psi _{m}}\Psi_m. At potentials close to zero, a soil is close to saturation, and water is held in the soil primarily by capillary forces. As θ decreases, binding of the water becomes stronger, and at small potentials (more negative, approaching wilting point) water is strongly bound in the smallest of pores, at contact points between grains and as films bound by adsorptive forces around particles.

Sandy soils will involve mainly capillary binding, and will therefore release most of the water at higher potentials, while clayey soils, with adhesive and osmotic binding, will release water at lower (more negative) potentials. At any given potential, peaty soils will usually display much higher moisture contents than clayey soils, which would be expected to hold more water than sandy soils. The water holding capacity of any soil is due to the porosity and the nature of the bonding in the soil.

 

 Please watch and read the full information below especially for Geotechnical Engineering Post Graduate Students.

Click Here_>>>>>Full paper Hons. Blight Lecture

Click Here >>>>>> Full video

Telaga Air Bumi Kahang, Kluang

KLUANG ; 25 JULAI 2017 – Masalah kekurangan bekalan air bersih yang membelenggu penduduk Orang Asli di Kampung Air Pasir, Kahang, dekat sini, sejak lebih 50 tahun yang lalu bakal diatasi dengan pembinaan telaga tiub baharu oleh sekumpulan penyelidik dari empat universiti tempatan.

 

Climate Change induced beach erosion

 

Beach profile changes are subjected to various parameters such as tides, currents and wave effect. This study investigates the beach profile changes at Teluk Gorek Beach, Mersing and to evaluate the effect of soil density on beach sediment. A total of seven beach profile cross- sections with offset of 20 m apart were established to monitor the presence of erosion and accretion. The monitoring work was done on January and March 2016 during spring tide. The estimation of erosion and accretion were performed by comparing the profile obtained on January and March. The result shows that the beach profiles have experienced both erosion and accretion during the period of study. The soil density change varies to the erosion and accretion process. As a conclusion, the beach is slightly changes during the period of study. The density increase for erosion process while decrease when accretion takes place.

CLICK HERE FOR FURTHER DETAILS:—-> FULL PAPER

 

 

Gunung Pulai in the eyes of the world

Campbell Scientific had published our work in Gunung Pulai in December 2016 newsletter. We have been using their equipment supplied by SureChem  (Malaysia). Rain gauge and water level transmitter have been used as part of our integrated  Early Warning Systems developed by Department of Geotechnics& Transportation, Faculty of Civil Engineering UTM.  We also managed to produce SOP for early warning system for gunung pulai mudflow. The SOP currently is undertaking several process of copyright before been published to the public.

 

The full details of the newsletter  as below:-

 

Click here for the article—  Campbell scientific newsletter 

Lecture notes: MKAJ1033/SKAA4713 Advance Foundation- Problematic Soils

Problematic soils are those that make the construction of foundations extremely difficult. They include expansive soils, collapsing soils, and sanitary landfill. Their distribution can vary widely, both areas and with depth. However, the ability to identify these soils would be invaluable to developers and geotechnical engineers.

Besides that, problematic soil may also look on soil chemistry perspective. However on this lecture notes only we only touch upon on the geotechnical engineering prespective. Below is some discussion on acid, alkaline and saline problematic soils.

 

Click link below for further details:-

Lecture notes :-mkaj-problematic-soils

 

Problematic Soils: Type # 1. Acid Soils:

The soils with pH less than 6.5 and which respond to liming may be considered as acidic soils.

(a) Reasons for Acidity:

(i) Humus decomposition results in release of large amounts of acids. There by lowering the pH.

(ii) Rainfall: In areas with more than 100 cm rainfall associated with high R.H., Ca, Mg is dissolved in water and leached out due to this base saturation of soil decreases.

(iii) Application of elemental sulphur under goes reactions resulting in formation of H2SO4.

(iv) Continuous application of acid forming fertilizers like ammonium sulphates or ammonium chlorides results in depletion of Ca by CEC (cation exchange capacity) phenomenon.

(v) Parent Material: Generally rocks are considered as acidic, which contain large amount of silica (SiO2) when this combined with water, acidity increases.

(b) Characteristics:

(i) pH is less than 6.5

(ii) These soils are open textured with high massive Structure.

(iii) Low in Ca, Mg with negligible amount of soluble salts.

(iv) These soils appear as brown or reddish brown, sandy loams or sands.

(c) Injury to Crops:

(i) Direct Affects:

(1) Plant root system does not grow normally due to toxic hydrogen ions.

(2) Permeability of plant membranes are adversely affected due to soil acidity.

(3) Enzyme actions may be altered, since they are sensitive to pH changes.

(ii) Indirect Affects:

(1) Deficiency of Ca and Mg occur by leaching.

(2) Al, Mn and Fe available in toxic amounts.

(3) All the micro nutrients except molybdenum are available. So ‘Mo’ deficiency has been identified in leguminous crops.

(4) Phosphorous gets immobilized and its availability is reduced.

(iii) Effect on Activity of Microorganisms:

(1) Most of the activities of beneficial organisms like Azotobacter and nodule forming bacteria of legumes are adversely affected as acidity increases.

Crops Suitable for Cultivation

(e) Amelioration:

(i) Lime as reclaiming agent: Lime is added to neutralize acidity and to increase the pH, so that the availability of nutrients will be increased.

(ii) Basic slag obtained from Iron and steel industry can be substituted for lime. It contains about 48-54 per cent of CaO and 3-4 per cent MgO.

(iii) Ammonium sulphate and Ammonium chloride should not be applied to acid soils but urea can be applied.

(iv) Calcium Ammonium Nitrate (CAN) is suitable to acidic soils.

(v) Any citrate soluble phosphate fertilizer is good source of phosphorous for acidic soils.

(vi) Eg. Dicalcium phosphate (DCP), Tricalcium phosphate (TCP) Potassium sulphate is a suitable source of ‘K’ for acidic soils. But MOP is better than K2SO4 because CI of MOP replaces -OH ions, their by release of -OH ions tends to increase the pH.

Problematic Soils: Type # 2. Alkaline Soils:

Alkali soils are formed due to concentration of exchangeable sodium and high pH. Because of high alkalinity resulting from sodium carbonate the surface soil is discoloured to black; hence the term black alkali is used.

(a) Reasons for Alkalinity:

The excessive irrigation of uplands containing Na salts results in the accumulation of salts in the valleys.

(i) In arid and semi arid areas salt formed during weathering are not fully leached.

(ii) In coastal areas if the soil contains carbonates the ingression of sea water leads to the formation of alkali soils due to formation of sodium carbonates.

(iii) Irrigated soils with poor drainage.

(b) Characteristics:

(i) Saline soil has soil pH of more than 8.5

(ii) Ec is less than 4.0 m.mhos/cm

(iii) ESP (exchangeable sodium per cent) is more than 15

(iv) It has black colour that why it is also called as Black alkali

(c) Injury to Crops:

(i) High exchangeable sodium decreases the availability of calcium, magnesium to plants.

(ii) Dispersion of soil particles due to high exchangeable ‘Na’ leads to poor physical condition of soil, low permeability to water and air, tends to be sticky when wet and becomes hard on drying.

(iii) Toxicity due to excess hydroxyl and carbonate ions.

(iv) Growth of plant gets affected mainly due to nutritional imbalance.

(v) Restricted root system and delay in flowering in sensitive varieties.

(vi) Typical leaf burn in annuals and woody plants due to excess of chloride and sodium.

(vii) Bronzing of leaves in citrus.

(viii) It affects the solubility of zinc (Zn).

(d) Crops Suitable for Cultivation in Alkaline Soils:

(i) Barley, Sugar beet, Cotton, Sugarcane, Mustard, Rice, Maize, Red gram, Green gram, Sunflower, Linseed, Sesame, Bajra, Sorghum, Tomato, Cabbage, Cauliflower, Cucumber, Pumpkin, Bitter guard. Beetroot, Guava, Asparagus, Banana, Spinach, Coconut, Grape, Date palm, Pomegranate.

(e) Amelioration:

(i) The process of amelioration consists of two steps:

(1) To convert exchangeable sodium into water soluble form.

(2) To leach out the soluble sodium from the field. Amendments used for reclamation of Alkali soils.

(ii) Gypsum:

(1) It is slightly soluble in water. So it should be applied well in advance.

(2) For every 1 m.e. of exchangeable Na per 100 gm of soil, 1.7 tones of Gypsum/acre is to be added.

(3) If the requirement is 3 tonnes/acre- apply in one dose.

(4) If the requirement is 3 to 5 tonnes/acre- apply in 2 split doses.

(5) If the requirement is 5 or more tonnes/acre – apply in 3 split doses.

(iii) Use of Pyrites (FeS2) .

(iv) Sulphur present in pyrites causes decrease in pH of soil due to formation of H2SO4.

(v) Application of sulphur.

(vi) Application of molasses.

(vii) Drainage channels must be arranged around the field.

(viii) Growing the green manure crops and incorporates in the field.

Problematic Soils: Type # 3. Saline Soils:

The saline soils contain toxic concentration of soluble salts in the root zone. Soluble salts consist of chlorides and sulphates of sodium, calcium, magnesium. Because of the white encrustation formed due to salts, the saline soils are also called white alkali soils.

(a) Reasons for Salinity:

In arid and semi arid areas salts formed during weathering are not fully leached. During the periods of higher rainfall the soluble salts are leached from the more permeable high laying areas to low laying areas and where ever the drainage is restricted, salts accumulate on the soil surface, as water evaporates

(i) The excessive irrigation of uplands containing salts results in the accumulation of salts in the valleys.

(ii) In areas having salt layer at lower depths in the profile, seasonal irrigation may favour the upward movement of salts.

(iii) Salinity is also caused if the soils are irrigated with saline water.

(iv) In coastal areas the ingress of sea water induces salinity in the soil.

(b) Characteristics:

(i) Saline soil has soil pH of less than 8.5

(ii) EC is more than 4.0 m.mhos/cm

(iii) ESP (exchangeable sodium per cent) is less than 15

(iv) Dominated by sulphate and chloride ions and low in exchangeable sodium

(v) Flocculation due to excess soluble salts.

(vi) High osmotic pressure of soil solution

(vii) Presence of white crust

(viii) It has white colour that why it is also called as White alkali

(c) Injury to Crops:

(i) High osmotic pressure decreases the water availability to plants hence retardation of growth rate.

(ii) As a result of retarded growth rate, leaves and stems of affected plants are stunted.

(iii) Development of thicker layer of surface wax imparts bluish green tinge on leaves during to high EC germination per cent of seeds is reduced.

(d) Crops Suitable for Cultivation in Saline Soils:

(i) Barley, Sugar beet, Cotton, Sugarcane, Mustard, Rice, Maize, Red gram, Green gram, Sunflower, Linseed, Sesame, Bajra, Sorghum, Tomato, Cabbage, Cauliflower, Cucumber, Pumpkin, Bitter guard. Beetroot, Guava, Asparagus, Banana, Spinach, Coconut, Grape, Date palm, Pomegranate.

(e) Amelioration:

(i) The salts are to be leached below the root zone and not allowed to come up. However this practice is somewhat difficult in deep and fine textured soils containing more salts in the lower layers. Under these conditions, a provision of some kind of sub-surface drains becomes important.

(ii) The required area is to be made into smaller plots and each plot should be bounded to hold irrigation water.

(iii) Separate irrigation and drainage channels are to be provided for each plot.

(iv) Plots are to be flooded with good quality water up to 15 – 20 cms and puddled.

(v) Thus, soluble salts will be dissolved in the water.

(vi) The excess water with dissolved salts is to be removed into the drainage channels.

(vii) Flooding and drainage are to be repeated 5 or 6 times, till the soluble salts are leached from the soil to a safer limit

(viii) Green manure crops like Daincha can be grown up to flowering stage and incorporated into the soil. Paddy straw can also be used.

(ix) Super phosphate. Ammonium sulphate or Urea can be applied in the last puddle. MOP and Ammonium chlorides should not be used.

(x) Scrape the salt layer on the surface of the soil with spade.

(xi) Grow salt tolerant crops like sugar beet, tomato, beet root, barley etc. Before sowing, the seeds are to be treated by soaking the seeds in 0.1 per cent salt solution for 2 to 3 hours. Comparison between Saline and Alkaline SoilComparison between Saline, Saline Alkaline and Alkaline Soil