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In various aspects, peat soil is different from mineral soil. Peat is a biogenic deposit that emerged within the last 10,000 years, during the post-glacial (Holocene) era. Peat is a soft soil that is unable to support external loads without experiencing significant deformations. Tyre pressure from automobiles and/or aeroplane wheels on paved surfaces creates traffic load, which can manifest as static or dynamic types of loading. To resolve the problem with peat soils, a thorough understanding of the static and dynamic behaviour of peat is still required. Many people who live near regularly used highways feel traffic vibration, and it is important to comprehend the nature of this issue to make predictions about potential solutions to this problem. As such, this study aims to investigate the cohesion (c) and friction angle (φ) properties of peat soil after it has been subjected to cyclic stress. Monotonic triaxial tests are conducted to ascertain the initial shear strength characteristics of the soil. Cyclic triaxial tests are performed with half of their maximum deviator stress to simulate the behaviour of peat soil under various effective stresses and frequencies of loading that are applied with 100 number of cycles. After applying various numbers of cycles of dynamic loading, the post-cyclic monotonic shear strengths were subsequently evaluated. It has been noted that irregular behaviour tends to occur more frequently at higher frequencies, particularly between 2 and 3 Hz. With higher frequencies being applied, the reduction in cohesion and friction angle becomes more evident. Doi: 10.28991/CEJ-2023-09-04-010 Full Text: PDF

Peats originate from plants and denote the various stages in the humification process. This condition renders the peat extremely soft and can be considered problematic soil. Thus, this study is conducted to examine and comprehend the particularities of peat engineering behaviour in respect to the relationship effects to the shear stress and cyclic shear strain of peat soil various characteristics to establish suitable correlation. This study carried out by using triaxial testing described by geotechnical test standards BS-1377: Part 8: 1990. Methods of Testing Soils for Civil Engineering Purposes: Shear Strength Tests (Effective Stress) that required for consolidated undrained and consist of five main stages: saturation, consolidation, static, dynamic, and post-cyclic loading using the GDS Enterprise Level Dynamic Triaxial Testing System (ELDYN). The parameters of shear strength were obtained in the peak deviator stress at a maximum of 20% of axial strain by using an undisturbed sample with an effective pressure imposed of 25, 50, and 100 kPa. In this study, all specimens are subjected to cyclic loading up to 100 cycles based on a one-way loading system with strain-controlled conditions. Based on the analysis conveyed, the post-cyclic shear stress decreased compared to its initial value of about 65.56 kPa (PNpt-100 kPa) in static and decreased to 14.9616 kPa in post-cyclic (PNpt-25 kPa-1 Hz). The principal stress ratio (σ'1/σ'3) shows the maximum values of this ratio that are located in the narrow zone of 1.61 to 1.12. Doi: 10.28991/CEJ-2022-08-12-08 Full Text: PDF

This study presents the findings obtained in post-cyclic behaviour and degradation of shear strength from the static triaxial test, cyclic triaxial test and post-cyclic monotonic triaxial test to study the dynamic loading relationships with the degradation of shear strength after cyclic loading to the maximum strain effect due for Hemic peat soil and aim of this research was to assess the post-cyclic loading condition that brought to the understanding of secant modulus by using dynamic triaxial apparatus. It begins with a visual inspection of fibre characteristics. This is followed by an analysis of static, cyclic, and post-cyclic loading with stress-strain behaviour. Shear strength decreased and notched lower strength than its initial strength. As a matter of fact, PNpt-25 kPa from 1, 2, and 3 Hz are accumulated in the adjacent maximum strain. With regards to this maximum strain, the undrained shear strength ratio shows sequent decreases from higher to lower frequency applied. For instance, PNpt-25 kPa-1Hz to PNpt-25 kPa-3Hz recorded 1.16 to 1.13 undrained shear strength ratios, respectively. The secant modulus (Esec) for all specimens reflects decrement. The secant modulus for BSpt at an effective stress of 100 kPa in static monotonic is about 18.74 MPa, while in post-cyclic, the secant modulus expanded to 19.630 MPa cyclically loaded with 1 Hz. Unfortunately, the secant modulus returned to decline position when higher frequency applied at 2 Hz, where the secant modulus is about 12.781 MPa and continues to decline with 3 Hz at 7.492 MPa. Doi: 10.28991/CEJ-2022-08-10-015 Full Text: PDF

It is known that peat soil is highly compressible. A constituent of peat soil from Klias, Sabah covering a wide range of index properties of fiber contents, specific gravity, organic contents and moisture contents were subjected to one-dimensional consolidation tests. This paper presents the engineering properties and compressibility behavior of sapric type of tropical peat soil. In this role, the high compressibility of Klias peat stands out as a most significant engineering property. With this intention, the purpose of this paper is to provide a simple and analytical means for predicting the consolidation settlement of sapric peat deposit under loading. The rate of primary compression, after a certain time. Increases with the logarithm of time. Loading applied from low stress to high stresses started from 2, 6.25, 12.5, 25, 50, 100 and 200 kPa resulting in high compression index, Cc and ratio, C’c. The Klias peat soil represented sapric type of tropical peat with organic content is 98.43% and lower fiber content which is about 18% of the specimen. Compressibility index Cc, Coefficient of consolidation Cv, and Compression index, Cc, was identified as a crucial component of parameters in determination of settlements behaviour of peat soil. The coefficient of consolidation, Cv, was determined within the range of 1.264 to 12.911 cm2/min and requires special considerations in laboratory testing procedures and interpretation of results.

Geotechnical design commonly requires that the in-situ stiffness, strength and permeability of the ground be obtained. Laboratory based investigation often related with risk of sample disturbance and difficulties to replicate the in-situ stress condition which results in overestimation or underestimation. Application of geophysical methods in geotechnical investigation previously was limited to targeting and dimensioning sub-surface features due to lack of resolution. However, rapid developments of geophysical methods result in the application of these methods in providing geotechnical design parameters. Multichannel analysis of surface waves (MASW) and seismic refraction were among the geophysical methods capable of obtaining stiffness parameters including the maximum shear modulus (Gmax) and maximum elastic modulus (Emax). The study revealed the efficiency of these methods to measure the small strain stiffness of peat soil with high accuracy as the results obtained were found to be similar to those obtained by previous researchers. Overall, the Gmax and Emax values of peat soil obtained range from 0.49 to 1.72 MPa and 1.46 to 5.15 MPa respectively. The Gmax and Emax values obtained shows significant increase with depth governed primarily by the effective stress. Other parameters such as degree of decomposition and peat thickness also shows potential influence on the Gmax and Emax values obtained.

Shale is significantly weaker and less durable than other types of rock and is easy to break when it is exposed to continuous wetting and drying activities. As a construction material, the durability strength index of weathered shale in Ayer Hitam, Johor, Malaysia is poorly investigated and not well understood. The purpose of this study is to investigate the effect of mechanical weathering on the durability strength index of Ayer Hitam weathered shale under several different conditions. Three hundred sixty samples of weathered shale which are classified as weathering grade II to IV were tested within the fifth cycles of the slake durability test under three different conditions namely: Natural weathering, dry, and saturated sample. The results showed that the weathered shale with the highest moisture content of 27.78% and the lowest strength index with 1% after the fifth cycle at week 8 was the weathering grade IV under saturated condition. It was also found that the reduction in the durability strength index was more than 90% with increased moisture content and weathering grades. In conclusion, the durability strength index of shale depends upon the number of cycles or weathering grade, duration of water immersion as well as moisture content.

Peat soil classified as high organic content with diverse range of fibers, distinctive intrinsic properties with low shear strength. The behaviour of peat soils under dynamic loading conditions has been studied. Therefore, a series laboratory of cyclic triaxial test on peat soil carried out to determine the effect of cyclic loading to the peat soil behavior after subjecting to cyclic loading is presented. In this study, the frequencies applied for the dynamic testing on the peat soil samples were focused and simulated on traffic vehicle loading frequencies, earthquakes and machine operations. Peat soil sample used from Parit Nipat, Malaysia (PNpt) with natural moisture content, m = 603% and liquid limit of wl = 231%. A series of undrained cyclic triaxial test were performed on undisturbed peat soil sample under isotropically consolidated specimens. In addition, the strain of amplitude applied is 0.1% to investigate the effectiveness of large strain amplitude response by allowing the generation of cyclic pore pressure and developed stress-strain cycle during cyclic loading. Correspondingly, the undrained Young’s modulus of the undrained shear strength subjected to cyclic loading in this study in the range of 60 to 70 for hemic peat soil. The specimen loaded into specific frequency causes in reduction of Young’s modulus related to stiffness and more pronounced in softening behaviour. The hysteresis-loops profile with regard to E parameters from 1st cycle to 100th cycles of Young’s modulus, E (MPa) for PNpt degrades precisely to an applied effective stress, 0.4 MPa (25 kPa) and 0.4 MPa (50 kPa). Cyclic loading frequencies resulted in decreases of the Young’s Modulus of peat soil that related to stiffness and more pronounced in softening behaviour. The result indicates that a reduction effect in the stress-strain cycle occurs in a peat soil from the initial stage of cyclic loading towards the end of 100th cycles due to the repeated loading application.

The pre-construction works include the geotechnical investigation which comprises the surface and subsurface exploration. Sub-surface exploration often causes several difficulties such as high cost, time consuming, localized investigation and intrusive. Furthermore, investigation on soft soil such as peat often raises several additional problems such as high risk of sample disturbance, difficult access for heavy equipment and inconsistent data due to the heterogeneity of peat. The advancement of geophysical method such as Electrical Resistivity Tomography (ERT) allows the determination of soil profile in time-efficient manner, economic, larger volume of investigation and non-intrusive. This study focused on the determination of soil profile, particularly peat layer using ERT method with complement from peat sampler data. The study was conducted at Parit Nipah, Johor. The results revealed a high accuracy profile delineated by the ERT method with only less than 8% percentage of error as compared to peat sampler profile. The comparison between Schlumberger and Wenner array showed that; the Schlumberger showed superior depth of penetration, with almost 3 times deeper penetration relative to Wenner. The Schlumberger array is also able to delineate lateral variation within the peat layer. Finally, the resistivity value of peat obtained ranged from 100.8 to 139.5 ohm.m with both arrays having consistent results.

Soil stabilization is a well-known methods for the treatment problematic soils. Its advantages over soil replacement include low cost and fast implementation. The alkaline activation of soft soils is a new technique that has been proposed recently to stabilize soft soils. However, its strengthening mechanism and the final product in terms of stiffness and brittleness resemble those observed in cemented soils. In other words, the residual strength which emerges when approaching failure is very low, and this results in immediate damage to building structures. These shortcomings need to be overcome, particularly in places where seismic loading can be expected. In the case of cemented columns under heavy embankments, horizontal displacement is likely to occur under seismic loading. This will result in the failure of stabilized material due to frail bending moments, making greater residual strengths more important than higher peak strengths. To address this problem, a fix fly ash content of 40% and polypropylene fibers in the range of 0.5%, 0.75%, 1%, and 1.25% were considered. Compressive, flexural and indirect tensile strength test results revealed the feasibility of polypropylene fibers to improve post-peak behavior, thus allowing for higher residual strength after failure.

Peat is considered problematic soil due to its large void ratio, high compressibility and low shear strength. Various ground improvement methods have been developed in recent years to improve peat’s strength properties. Polyurethane grouting is one of the ground improvement methods that is gaining recognition as effective and fast way to stabilize soil. Polyurethane is a lightweight material produced by mixing polyol and isocyanate chemicals. Upon mixing, a polyurethane foam is created which expands up to a few times of its original volume. In this study, the strength characteristics of polyurethane with different mix ratios of polyol to isocyanate were evaluated to determine the optimum ratio suitable to be used to stabilize peat. Polyol to isocyanate ratio of 1:1, 1:1.5, 1:1.2, 1:2.5 and 1:3 were tested in this this research. The propagation, microstructure and density of polyurethane were investigated. Compressive strength of polyurethane determined using Unconfined Compression Strength test. Polyurethane created with higher ratio of isocyanate bears higher density and compressive strength compared to the polyurethane with lesser quantity of isocyanate. The cell structure of the polyurethane also is smaller with thicker cell walls. However, the curing time consumed by the polyurethane with high ratio of isocyanate is 8 times greater than the normal polyurethane. Thus, polyurethane ratio with fast curing time and high compressive strength was chosen as the optimum mix ratio to be used to stabilize peat.

The application of the MASW method on engineering investigation required optimization of the field configuration to ensure high quality dispersion image for reasonable shear wave velocity profile estimation. The limited investigation with respect to peat soil condition has motivated the study to determine the optimum field configuration for peat soil. The challenging characteristics of peat soil including high void ratio, compressibility, water content and low shear strength further complicates the determination of optimum field configurations. The study focused on the determination of optimum field configurations for active MASW method which includes the receiver spacing, source offset, sensor frequency and sampling interval. The results obtained shows that, the optimum receiver spacing to obtain high signal to noise ratio dispersion image was 1 meter. Smaller receiver spacing causes domination of higher modes and wide bandwidth, while longer receiver spacing causes significant drop in signal to noise ratio governed by rapid energy dissipation with distance. For the source offset, the distance of half the total spread length (X1 = L/2) provides the best resolution and minimised near-field and far-field effect. While, 4.5 Hz sensor frequency and sampling interval between 100 to 250 s provides sufficient low frequencies for deeper depth investigation and denser data. Overall, the influence of receiver spacing, source offset and sensor frequency on the dispersion image resolution was significant.

The post-cyclic yield shear strength and initial stiffness of a peat soil after subjecting to cyclic loading is a major topic in this study. Due to the effects of cyclic loading, post-cyclic shear strength decreases lower than its initial strength. A series laboratory static and cyclic triaxial test followed by post-cyclic monotonic tests carried out to determine the yielding parameters. Tests were carried out on the undisturbed samples taken from Parit Nipah, Johor and Lumadan, Sabah within west and east Malaysia peat soils. Postcyclic loading test conducted with effective stress 100 kPa with frequency 1.0Hz. The initial stiffness is the initial tangential modulus with yield shear strength was half of the deviator stress in which two tangential lines intersect. The post cyclic yield shear strength of undisturbed peat soil is considerably lower compared to static at the axial strain of only 1.4% and 1.5%. The Parit Nipah and Lumadan peat are classified as Hemic

Subgrade soil is the important material as the foundation for supporting the pavement layers and the repeated load of vehicle traffic. To characterize the stiffness and strength behavior of subgrade due to traffic loading in structural pavement design can be determined by resilient modulus and unconfined compressive strength test. In this study, laboratory test of resilient modulus and unconfined compressive strength used to investigate (1) the effect of moisture content of the changes of stiffness and strength characteristics, (2) the correlation between the resilient modulus and elasticity modulus. The soil sample prepared at five type of compacted soils, at the dry side (OMC-20%OMC and OMC-10%OMC), OMC and at the wet side (OMC+10%OMC and OMC+20%OMC) . The result shows the moisture content has a significant effect on cohesive soil, the resilient modulus, modulus elasticity and stress value increase with the increase of moisture content until reaching the optimum moisture content (OMC) and then decrease with the increase of moisture content on the wet side of OMC point. By comparing both resilient modulus and unconfined compressive strength result from ANOVA statistics analysis can be concluded that there is no difference in stiffness between resilient modulus and modulus elasticity methods.

Peat is considered as a very challenging soil when constructing any structure. It’s known with high compressibility, high moisture content, low shear strength and long term settlement when subjected to load. These characteristics always posed constant problem for sustainable construction on peat. This study aims to investigate the settlement behaviour of peat fortified with concrete slab under embankment loading through full scale testing at Parit Nipah, Johor, Malaysia. The peat is categorized as hemic with moisture content greater than 500%. A concrete raft sized 3.6 m x 3.6 m with thickness of 150 mm was built on the site. The 3.6 m x 3.6 m slab was subjected to non-uniform loading. Results indicated that the installation of slab on peat able to reduce the settlement of peat under embankment loading. The study shows potential to mitigate or reduce long term post construction settlement on peaty ground.

The study investigates the influence of source weight, type of source plate and number of stacking on the resolution of the dispersion image obtained from the active Multichannel Analysis of Surface Waves (MASW) method at peat soil condition. Fundamental-mode dispersion curve determination is governed by the optimum configuration of the active MASW method. Optimum configuration will ensure reliable inverted shear wave velocity profile. The heterogeneity and problematic characteristics of peat soil provide challenges on the MASW survey. Based on the field tests conducted, the effect of the source weight was significant. Heavier source weight relatively increases the dispersion image resolution especially at lower frequencies but sacrificing the resolution at higher frequencies. Therefore, heavier source weight (i.e. 7 kg sledgehammer) was recommended for deeper depth of investigation with little concern on the shallow depth. The use of rubber plate also contributed to the increases of energy accumulation at lower frequencies. Increasing number of stacking increases the overall energy band as the stacking allows significant suppression of the ambient noise. 5 to 10 stacks were recommended for peat soil condition. Finally, overall comparison between the dispersion images obtained at both locations shows that thicker peat soil layer results in lower resolution and low signal-to-noise ratio dispersion image.

Active MASW method is a promising method to determine the stiffness characteristics of the subsurface strata. The accumulation energy to obtain high-resolution dispersion image depends largely on the energy generated from the active source. From the results obtained, the influence of different source energy, source plate and number of stacking on the dispersion image resolution were significant. Heavier source weight (e.g.7 kg sledgehammer) produced highamplitude energy band and provides even lower frequencies. However, if lighter source weight (e.g. small steel hammer) was used, it needs to be coupled with rubber plate to increase the low frequency content, thus generate deeper depth of investigation. Finally, the use of rubber plate and stacking increased the resolution of the dispersion image especially at lower frequencies by significantly suppressing the ambient noise.

In this paper the potential of introducing alkali activated fly ash to a clayey soil as stabilizing agent was investigated. As alkaline activator Potassium hydroxide of 12 M was introduced to the soil fly ash mixtures. Unconfined compressive strength tests were carried out. Four different fly ash/solid ratios were proposed to be 10 %, 20 %, 30 % and 40 % at two curing regimes of 7 & 28 days. The greatest unconfined compressive strength was of 40 % mixture recorded at 3.68 Mpa after 28 days. Microstructural analyses including SEM, EDS and FTIR were conducted to detect and confirm gel formation. Alkaline activation of clayey soil using KOH solution as an activator proved to be a feasible alternative for soft soil stabilization.

In recent years, geologist and soil scientist have increasingly sought out organic soil, including peat in tropical regions to study their characteristics and agricultural potential for new development area. However, few studies had been made to analyse the consequences of cyclic loading onto peat. The aim of this study is to determine and analyse the behaviour of dynamic parameters on different locations of peat using cyclic triaxial test. Sample preparations and testing methods on analysing the dynamic parameters are briefly explained. Results on Index Properties test and Cyclic Triaxial test are presented for all peat locations. It has been concluded that the behaviour of damping ratio, D and dynamic shear modulus, G in PNpt, POpt and SBpt are influenced by its morphology characteristics which controls the basic physical and chemical properties of peat. The structural elements that contained in peat samples such as fibres are could also be the major causes pertaining to the Malaysia’s peat dynamic parameters behaviour.

Peat soils occur in many countries and formed naturally through the decomposition of plant and animal matter. These soils are known as a very problematic soft soil due to its low bearing capacity and high compressibility. These two main factors may be based on the characteristics of the soil itself. This study is focused on its physical properties and shrinkage measurement. It is also to investigate the shrinkage measurement that obtained from the diameter at four dimensional points and bar linear shrinkage method for both location peat sample. There are varies method that can be used in order to obtain a full description of the shrinkage behavior of peat. The sample was taken from two different locations which are Parit Nipah and Pontian. Linear shrinkage method is used to determine the soil shrinkage from linear measurements on a bar mould with disturbed soil that passing 0.425mm sieve. However, this method was modified by using undisturbed sample to compare the result with bar linear shrinkage method and the measurement was obtained by the reduction of its diameter at four points of the sample. Linear shrinkage values obtained from Parit Nipah and Pontian by following British Standard method are 34.77% and 33.09% respectively while modified linear method gives the value of 35.25% for Parit Nipah and 32.85% for Pontian. Modified method shows that peat soil from both locations shrinks in irregular shape due to Point C of Parit Nipah and Pontian peat sample has the smallest diameter compared to other points within 24 hours oven-dried. It also shows that Parit Nipah peat soil has a higher percentage of linear shrinkage for both method instead of Pontian peat soil. The linear shrinkage values that obtained from bar linear shrinkage and modified linear shrinkage gives smaller different values which is nearly same for both method.

This paper shows the stress-strain behavior of peat from the perspective of geotechnical engineering based on laboratory test. Stress happens when a load applied to a certain specimen and deformed the specimen while strain is the response from applied stress on a specimen. Peat is known as an ultimate soft soil in engineering terms because it has low shear strength and compressibility. This research is concerned about the stress-strain behavior of hemic peat. The undisturbed samples were collected at Parit Sulong and Parit Nipah, Batu Pahat, Johore, Malaysia. Normal stresses are 12.5kPa, 25kPa, 50kPa and 100kPa. The shear rate to determine the stress-strain on peat is 0.1mm/min. It is a drained condition test. Both results from each method that obtained were compared based on the relationships of stress-strain. Parit Sulong has higher stress-strain than Parit Nipah. If shear stress increased, shear strain also increased. The result shows that, direct simple shear test of stress-strain that tested on hemic is more relevant than a direct shear box because DSS shear the entire specimen of peat while DSB only shear at the center of the specimen. Geotechnical engineers can use the direct simple shear method to understand efficiently about the stress-strain behaviour of peat.

This paper compares some geotechnical properties of Kaolin, Laterite and Peat. Laterite was collected from Bukit Banang while Peat sample was collected from Parit Nipah, both locations were in Batu Pahat, Johor. Meanwhile, kaolin that was used in this research was manufactured kaolin. These soil samples were subjected to routine laboratory analysis and resulting data were analyzed statistically using a correlation analysis. A laboratory testing program consists of “Basic properties test” to obtain general information on the materials (e.g Natural moisture content, Atterberg Limit, Specific gravity, grain size analysis, chemical composition and pH) and “Geotechnical properties tests” to measure specific properties that characterize soil behaviour for design and constructability assessments (e.g Standard Proctor Test, Unconfined Compressive Strength and CBR).The results showed that the Natural/initial moisture content for laterite, peat and kaolin is 22.54%, 480.61% and 0.22% respectively. Meanwhile Specific gravity for each soil was in the range 1.50-2.79.It was also found that the pH of all soil is acidic which lay in the range of 3.76-5.95.The UCS for the optimally compacted sample of laterite is 445.77 kPa, kaolin is 199.23 kPa and for peat is 58.70 kPa. This paper summarizes the result of analysis performed on all tests conducted. Based on the results, the geotechnical property of the soil is a highly dependent with the type of soil and therefore, determining the soil characterization and the soil strength should be considered during the planning phase of any earthwork construction operation.

Peat soils are challenging soils which are a problem for many geotechnical engineers especially in the design of shallow foundations and road constructions. The engineering properties of peat are dependent on the nature of its physical properties. Micro structural studies done on the soil shows that it consists of fibres which cause the soil to be highly compressible resulting in excessive settlement when they are subjected to moderate load increments or vibrations produce by traffic. In this paper, dynamic testing was done to approximately simulate traffic loading characteristics on peat taken from Parit Nipah and Pontian, Johor using a cyclic triaxial testing with 1Hz loading frequency. The results were compared with soil that has a stiffer particulate nature such as sand. The comparison showed that the dynamic loading parameters of dynamic shear modulus and damping ratio of peat was dependent on the fiber content and was very much lower than that of well graded and uniform sands. This can be an important indication to understand the key parameter behaviour of peat that must be taken into account when designing and managing infrastructures on peat soils.

Soil velocity profile often used as subsurface characterization by using geophysical technic. Seismic refraction is one of geophysical technique to determine primary wave (p-wave) velocity of soil profile. In this paper, seismic refraction technique has been performed on two different types of soft soil (peat soil and RECESS clay) for comparison of its p-wave velocity soil profile. From p-wave velocity soil profile comparison, its show the peat soil has soil velocity range from 211 m/s – 534 m/s at depth of 0 – 4 m while the soft clay show soil velocity range from 248 m/s – 1842 m/s at depth of 0 – 5.5 m. The profiles of peat soils and RECESS clay have been verified using peat samplers and existing borehole data. Both of velocity soil profiles, indicated that peat soil have lower velocity compare with soft clay due to its unique and soft soil characteristics. The difference of p-wave velocity soil profile between peat soil and soft clay are clearly showed both soils have different soil p-wave velocity with different soils characteristics.

Strength and deformation parameters of compacted soil are known to be related to soil type and moisture. However, little attention has been directed towards understanding the influence of compaction energy on soil type and moisture. This study considers the effect of different compaction energy on certain geotechnical properties of Kaolin and Laterite soil. This paper describes a laboratory study conducted to evaluate the relationship between soil type, soil moisture content with different compaction energy and strength characteristic. Specimens were compacted with impact energy at levels of 596 kg/m3(Standard Proctor) and 2682 kJ/m3 (Modified Proctor) over a wide range of moisture contents to determine dry unit weight, and Unconfined Compression Strength Test (UCS). Result shows that compaction energy is an important factor in determining soil strength that should be considered during the planning phase of any earthwork construction operation.

In this study, a laboratory investigation was conducted to examine the performance of TerraZyme on different soil types. Laterite and kaolin were treated with 2% and 5% TerraZyme to determine changes in the soils’ geotechnical properties. The obtained results were analysed and investigated in terms of compaction, Unconfined Compressive Strength (UCS) and California Bearing Ratio (CBR). The changes in geotechnical properties of the stabilised and unstabilised soils were monitored after curing periods of 0, 7, 15, 21 and 30 days. Changes in compaction properties, UCS and CBR were observed. It was found that laterite with 5% TerraZyme gave a higher maximum dry density (MDD) and decreased the optimum moisture content (OMC). For kaolin, a different TerraZyme percentage did not show any effect on both MDD and OMC. For strength properties, it was found that 2% TerraZyme showed the greatest change in UCS over a 30-day curing period. The CBR value of stabilised kaolin with 2% TerraZyme gave a higher CBR value than the kaolin treated with 5% TerraZyme. It was also found that laterite treated with TerraZyme gave a higher CBR value. Lastly, it can be concluded that TerraZyme is not suitable for stabilising kaolin; TerraZyme requires a cohesive soil to achieve a better performance.

Biochar (a by-product of biomass pyrolysis) is developed as a renewable, low-cost, and promising carbon-based electrode for electrochemical remediation of Cr, Mn and Fe in polluted river water. The biochar - electrode were prepared with two types of tailored sieved size medium (2.0 mm) and fine (150 µm). The effect of the different sieved size on the electrochemical reactor was set at 60V of voltage supply, 6 cm inter-electrode distance within 105 minutes electrolysis operational time. The results indicated that the highest removal efficiency for Cr was achieved at 95% after 105 minutes followed by Mn at 99.9% in 65 minutes and Fe at 92.76% in 105 minutes. Interestingly, the electrode with larger sieved size showed the highest removal efficiency for all three elements. These results emphasize the importance of tailoring the porous structure of the biochar electrode material as a function of the specific size of adsorbate ions to improve the electrochemical water treatment performance for polluted river water.

Soft soil is well known to have low bearing capacity, high water content, high differential settlement, long term settlement and not able to sustain external loads without having large deformation. A study was conducted to measure the settlement at two bridge approaches on soft soil area in Batu Pahat, Johor. The settlements not only cause uncomfort to road users but may be dangerous to road users as drivers tend to reduce speed drastically while approaching the bridges. This paper specifies and presents the settlement values of bridge approaches as well as identifies the critical areas. The result of this study indicates that the settlement value is higher in the area approaching the bridge and more critical than the settlement in the area leaving the bridge. In addition to these results, a description of the measurement technique, field data collection and procedures are presented.

Soft soil always deal with high compressibility, high water content, low shear strength and low permeability. All these challenges lead to soil failure such as excessive settlement, failure of sub structure which is lead to superstructure damage and many others failure. Hence, soil stabilization is one of the option in ground improvement technique by adding other stabilization agent either natural basis or chemical basis. This paper critically reviewed about advantages and disadvantages of chemical stabilizer namely traditional and non traditional. Also closely reviewed on polymer and lignosulfonate as soil stabilization agent in various type of soil. Reviewed and analysing of some references revealed that using non traditional stabilizer have more advantages than traditional stabilizer in term of engineering properties as well as chemical composition. Polymer and lignosulfonate also have their on specialties in order to corporate with various type of soil.

This paper discusses the resilient behaviour of various materials of high rigidity, high elasticity and of particulate materials. The resilient behaviour is measured by the resilient modulus (Mr) test which is the mechanical response of soils to a dynamic cyclic load which simulates traffic loading conditions and it is an important parameter in the design of both flexible and rigid pavements. The materials used are of a concrete cylinder, a rubber sample and particulate materials which are sands of different particle size and shape classification. The design resilient modulus follows a constitutive model and it is used to compare the resilient behaviour of each material. The constitutive model shows that the design resilient modulus is affected by the particulate characteristics and how it can be related to a stiff and flexible material.

Building construction on soft soils including on peat has many challenges and difficulties. The failed and deteriorated buildings have a big impact on the community. The IConCEES International Workshop 2015 which was conducted on October 2015 convened as a joint venture between Universiti Tun Hussein Onn Malaysia (UTHM) and the University College of Technology Sarawak (UCTS). The aim was to invite regional experts from academia and the industry to formally present and discuss the various construction problems encountered when working with peat. The discussions were divided into two divisions; infrastructure and building construction. This paper discusses the outcomes of the workshop and focuses on the factors and relevant challenges when constructing buildings on peat. The experts have discussed regulatory and construction issues including: drainage issues, site investigation practices, monitoring and construction guidelines. A few suggestions were outlined as a remedy to these problems and to better assist the peat practitioner at work.

Challenging, problematic and non-uniform ground conditions are a night mare to geotechnical engineers tasked with the design and construction of buildings and transport infrastructure. These often suffer undesirable structural settlements. Designing within the current understanding of geotechnics; settlement in peat and organic soils need to be recognised to include the known “primary and secondary consolidation characteristics” and the lesser known “tertiary consolidation phase”. These eventually contribute cumulatively to the consequential uneven and hazardous “bumpy road” surfaces. Undulating flexible road pavements result primarily from the transference of the heavy self-weight of the embankment fill to yielding and non-uniform subgrade. The adoption of conventional design/repair methods such as pile, vertical drain, soil replacement and soil stabilisation are expensive and inappropriate in very soft ground conditions. These then lead to unjustifiably high and repetitive maintenance costs. There being no one quick fix solution for all; pragmatic research must necessarily identify the best/progressively improved practical and sustainable solution. A viable solution is to develop criteria and explore the concept of a “masonry arch bridge structure/lintel-column structure” and adopting sustainable materials through pragmatic searching for appropriate recyclable waste materials. This will lead to the basis for a sustainable, innovative, strong, stiff, permeable composite mat structure that can be used on soft and/or yielding ground conditions. Conceptual lightweight fill technology including the popularly used expanded polystyrene (EPS) and the innovative composite mats recently being developed by the research team are outlined.

A good subgrade for road pavement is required to support the traffic load that passes through. The characteristics of the subgrade is determined by the stress-strain behaviour that is expressed as a resilient modulus. The performance of the pavement is affected by characteristics of the subgrade. Characteristics of clay soil generally have a low of bearing capacity, especially to support the load induced by the wheel load of vehicles. Clay soil is very sensitive to changes of temperature and moisture content. The changes of moisture content cause the changes on the subgrade‚s resilient modulus value. This paper studies the resilient modulus of the subgrade of clay soil by laboratory testing. To investigate the effect of moisture content, this testing is done on a dry side, OMC condition and wet side. The result shows the difference of the resilient modulus characteristic and deformation that is influenced by the moisture content.

Soils at many sites do not always have enough strength to bear the structures constructed over them and some of the soil may need to be stabilized in order to improve their geotechnical properties. In this paper, routine laboratory tests were critically carried out to investigate the efficacy of lignin in improving the strength behaviour of the soils. Two different soil samples (laterite and kaolin) were studied and mixed with different proportions of lignin (2% and 5% of dry weight of soil), respectively. Unconfined Compressive Strength (UCS) characteristics evaluated in this study were done on samples at their maximum dry density and optimum moisture content (obtained from compaction tests). The UCS tests on all the specimens were carried out after 0, 7, 15, 21 and 30 days of controlled curing. The research results showed that the addition of lignin into kaolin reduced its maximum dry density while giving progressively higher optimum moisture content. Contrarily, with the laterite soil, both maximum dry density and optimum moisture content simultaneously increased when lignin was added into the soils. The UCS results showed that the the stabilized laterite with 2% lignin continued to gain strength significantly at a fairly steady rate after 7 days. Unfortunately, lignin did not show a significant effect in kaolin.

Peat soils occur in many countries and naturally formed by the decomposition of plant matter. It will give rise to an extreme of challenging ground conditions and peat soils also are known as a very problematic soft soil. For peat soil condition, shrinkage effect is one of the factors that can affect the strength and moisture content of soils. The aim of the study is to evaluate the shrinkage measurement of peat soils with modified techniques to compare with the British Standard method. Peat samples were collected from Parit Nipah (PPN) and Pontian (PP). Linear shrinkage of undisturbed peat soil is observed every hour until there are no volume changes. Linear measurement for modified method that using undisturbed sample is extremely different and higher than British standard method which is using reconstituted soil sample that had been sieve passing 425 μm. Sieve process will disrupt the composition of actual peat soil because it will remove any decomposed plants. The shrinkage measurements during the drying process influenced the volume of peat soils as the volume decreases when the soil is shrunk.

Stress can produce a deformation because real material is not rigid, the deformation will measure the strain. Stress-strain is important in determining peat behaviour. Peat cannot support too much load on it because of peat have very low strength, high compressibility and long-term settlement. The objective of this study is to determine the behaviour of stress-strain characteristic using different test. The undisturbed samples were collected at Parit Nipah, Batu Pahat, Johore, Malaysia. The tests are direct simple shear and direct shear box. These methods cover the determination of the stress-strain relationship of peat and to investigate the behaviour of peat. Normal stresses are 12.5, 25, 50 and 100 kPa with 0.1 mm/min rate of shear. This study is to know the stress-strain between direct simple shear test and direct shear test based on peat specimens of hemic. The test results will contribute and establish the drained shear characteristic of testing peat. It shows that direct simple shear test stress-strain is increasing clearly than direct shear test. Besides that, direct simple shear is suitable to use on peat soil rather than direct shear box. This research can help the geotechnical engineers and can be used in the development of foundation and as well as constructions.

Peat soils impose special problems in Geotechnical Engineering design as well as Civil Engineering and constructions. Most of researchers conducted investigations on the dynamic loading of soft soils such as sand and clay, but only a few had discovered the behaviour of peat in terms of static and dynamic loadings. Hence, this paper presents the behaviour of peat soil located in Pontian, Johor as well as to obtain the dynamic parameters of peat soil such as shear modulus and damping ratio by using different frequencies. The index properties test, static test and cyclic test have been performed to determine the characteristics and also the parameters required by using stress-controlled cyclic triaxial test of 1 and 2 Hz loading frequencies. All tests were conducted in RECESS, UTHM. The findings explained that Pontian peat behaves differently during the frequencies of 1 and 2 Hz. The shear modulus behaviour on the Pontian peat increase as the loading frequency and effective stresses increased. The results show that the maximum shear modulus of Pontian peat was 1.19 MPa for the frequency of 1 Hz and 1.4 MPa for 2 Hz. Both at effective stress of 100 kPa. Meanwhile, damping ratios show a reduction in the increasing of effective stress and loading frequency applied. The maximum damping ratio in 1 Hz frequency was noted at 44 % and the maximum value for 2 Hz was 35 %. Both at effective stress of 13 kPa. For further research, the cyclic loading can be conducted with different frequencies to show clearly the behaviour of peat in terms of dynamic loading and the cause of frequency influences should also be stated as it would affect the results pattern.

This paper was briefed about difficulty in seismic refraction during data acquisition on peat soils. Seismic refraction is commonly used for subsurface characterization. This method can determine the subsoil profile by differentiate its soil velocity. Peat is known with high compressibility and more 75 % of organic content that give challenges is seismic refraction. Challenges of seismic refraction such as attenuation of seismic wave, poor signal to noise ratio (S/N) and seismic source energy explained in this paper. This problem is common for geophysicist but technical purposes for engineering community is good to have better data acquisition. The purpose of this paper is to shown proper data acquisition for seismic refraction on peat soil. The raw data of seismic wave taken from seismograph for takeout spacing of 1, 3 and 5 m are shown in results and discussion for comparison of seismic data quality.

In any context, operation and management of transportation systems are key issues which may affect both life quality and economic development. In large urban agglomerations, an efficient public transportation system may help abate the negative externalities of private car use such as congestion, air and noise pollution, accident and fuel consumption, without excessively penalizing user travel times or zone accessibility. Thus, this study is conducted to appraise the Malaysian rural rail transit operation and management system, which are considered important as there are many issues and solution in integration of the services that need to be tackled more conscientiously. The purpose of this paper is to describe some of the most important issues on integration of services and rail transit system in Malaysian and how to solve or reduce these problems and conflicts. In this paper, it consists of the historical development of rail transit construction in Malaysia. This paper also attempts to identify the important issues related to rail transit services and integration in Malaysian rural rail operation and management system. Comparison is also conducted with other countries such as UK, France, and Japan. Finally, a critical analysis is presented in this paper by looking at the possible application for future Malaysian rail transit operation system and management, especially focusing on enhancing the quality of Malaysian rural rail transit. In conclusion, this paper is expected to successfully review and appraise the existing Malaysian rural rail transit operation and management system pertaining to issues & solution in integration. It is also hoped that reformation or transformation of present service delivery quality of the rail transit operation and management will enable Malaysia to succeed in transforming Malaysian transportation system to greater heights.

The dynamic behaviour of soil affected the mechanical properties of soil such as shear wave velocity, shear modulus, damping ratio and poisson's ratio [1] which is becoming important aspect need to be considered for structures influences by dynamic movement. This study is to determine the dynamic behaviour of Penor peat such as shear wave velocity using MASW and estimation its shear modulus. Peat soils are very problematic soils since it's have high compressibility, low shear strength, high moisture content and low bearing capacity which is very not suitable materials to construct any foundation structures. Shear wave velocity ranges between 32.94 - 95.89 m/s and shear modulus are ranging between 0.93 - 8.01 MPa. The differences of both dynamic properties are due to the changes of peat density and affected by the fibre content, organic content, degree of degradation and moisture content.

Construction of infrastructures on peat land is a very challenging task due to its properties of low shear strength, high compressibility and high water content. This paper summarizes various solutions which could be adopted for the construction of infrastructure on peat, as reviewed by the experts and panels during IConCEES International Workshop 2015. Engineers could (a) avoid peat, such as to transfer the load to the hard layers through end bearing piles or to replace the peat with the other soils, or (b) construct on peat with special precautions, such as by reducing the weight of the construction materials and dewatering the peat to improve the engineering properties. This paper serves to generate new ideas and give insights of the problems commonly encountered by the industry. Some of the proposed solutions might never be tested on peat. This would rely on the researchers to take up the challenge to further investigate and address the technical issues outlined in this paper.

The engineering structures are mostly constructed directly in contact with the ground and the response between the soil and the structure is termed as soil-engineering structure interaction. Peat is considered as unsuitable soil for supporting foundations in its natural state due to the high moisture content (>100%), high compressibility (0.9 - 1.5) and low shear strength (5-20 kPa) values. Peat also contains high organic matter (>75%), large deformation, high compressibility and high magnitude and rates of creep. Settlement is a common phenomenon in peat soil. The objectives of this study are to investigate and to analyse the deformation behaviour of the peat soil based on physical modelling and to critically compare it with sand. A model size of 200 cm x 50 cm x 90 cm was used with instrumentation (Displacement Transducers) to investigate and observed the deformation. The two different materials that were used are peat (remoulded hemic) and sand. Based on the results, deformation in sand corresponds to general bearing capacity failure and deformation in peat shows punching shear failure.