To determine the slow shearing rate for consolidation drained shear box tests (original) (raw)
Related papers
2014
The reduction of shear strength parameters of the soil in the slopes as well as the reduction of suction as the soil become saturated during prolonged rainy seasons are the two main causes of slope failures in Malaysian residual soils. In this study, a total of 227 shear strength parameters were obtained from 29 slope failures in Penang Island and Baling. Both locations are located in Northern Malaysia. In addition, 35 shear strength parameters were also obtained from 10 stable slopes, also at the same locations. Disturbed soil samples were taken at a depth of 100mm from the existing ground surface. Field bulk density tests were carried out at all the location where soil samples were taken. The field bulk density results were later used to re-compact the soil for the consolidated drained shear box tests to be carried out in laboratory. The objective of the research is to determine the threshold values of the effective shear strength parameters of soil taken from both the slope failu...
2017
Slope failures always occur in Malaysia especially during the monsoon seasons between October and January every year causing fatalities and damages to properties. The main factors causing the slope failure to occur are reduction of the shear strength parameters and loss of negative suction due to saturation of the slope. The objective of this study is to determine the effective shear strength parameters of the soil taken at slope failure using consolidation drain (CD) shear box and also to determine the factor of safety using SLOPE/W software. The soil samples were tested under submerged condition. The minimum value of effective shear strength parameters obtained from the CD shear box tests were c' = 0 kN/m 2 and ø' = 47.3 0 while the maximum value of c' = 30.2 kN/m 2 and ø' = 35.6 0. The FOS varied from 0.377 to 0.749 with minimum value of factor of safety was 0.377. When using SLOPE/W software on a stable slope cross section having minimum value of effective shear strength parameters, the minimum value of factor of safety was less than 1 indicating that the slope had already failed.
EVALUATION OF SHEAR STRENGTH PARAMETERS USING SHEAR BOX TESTS FOR SLOPE FAILURES IN PENANG
On 11th December 1993, Highland Tower near Hulu Kelang, Selangor toppled due to slope failure causing 48 residents to be killed. It became the worst nightmare to all Malaysians especially to the residents of the un-failed nearby tower as well as in the engineering lines. Since then, many more slope failures have occurred in Malaysia yearly during the rainy seasons. Hence, slope failure has been ranked as the worst natural disasters in Malaysia. Therefore, the studies on slope failures are becomes more important. Slope failure, also referred to as mass wasting, is the down slope movement of rock debris and soil in response to gravitational stresses. There are many factors affecting slope failures such as weaknesses in the composition or structure of the rock or soil; variation in conditions such as change in rainfall, unorganized drainage or surface stability (removal of vegetation). Among these factors, rainfall, earthquake and human activities are important starter factors that are causing slope failures to occur. This study is to determine the soil shear strength under saturated condition along Teluk Bahang-Balik Pulau road Penang. Saturated shear box tests were conducted to determine the shear strength for soil samples taken from slope failure locations
ARPN journal of engineering and applied sciences, 2019
The residual sedimentary soil is one of the largest residual soils in peninsular Malaysia. Its vast presence enables engineering activities to use this type of residual soil in the construction sector such as in construction of retaining walls and roads. Nevertheless, this residual soil often brings in heterogeneities because it is structurally complex and extensively weathered in most places which it can cause a structure to fail. This can be solved by determining the value of the shear strength parameter of the soil in a particular area. In order to determine the effect of sample’s dimension on the effective shear strength parameters of the samples, consolidated drained (CD) triaxial test was conducted on two different diameters size of 38 mm and 50 mm. This study shown that is has a significant effect in different sizes of sample used. 22.5 kPa and 32 ̊ were recorded for effective cohesion value, c' and effective friction angle, Ø’ for 38 mm soil samples and for 50 mm soil sa...
Stage construction of embankment is often obstructed by low bearing capacity of soil because of that critical height of embankment is smaller than final height of embankment design. Height of embankment construction will always be greater than final height requirement because of the settlement of soil. Due to the problems mentioned above, it is conducted the installation of PVD for accelerate consolidation settlement to reach the final height of the embankment with stable condition. The shear strength will be increased if the settlement consolidation completed so that the soil bearing capacity will also be increased. This study aims to analyze how much shear strength increase if settlement consolidation completed. By case study in Teluk Lamong, Indonesia where the soil is normally consolidated will look how much increase shear strength that occurs by using the Mohr method coulombs, Ardana & Mochtar (1999) and changes in volume method. Expected outcomes of this research are obtain a) new shear strength value on various condition of stage construction of embankment, b) Provide the method that are suitable for looking for increasing shear strength.
International Journal of GEOMATE, 2019
Consolidated drained triaxial compression tests (CD) were conducted to determine the compression properties of remolded samples collected from hillslope in residual soil. The test results showed that the effective drained shear strength of residual soil was primarily affected by the degree of weathering according to depth, parent rock material, and clay contents and also influenced by initial moisture content. These samples were classified as silt soils of high to low plasticity. CD tests were performed on samples prepared under 100 and 200 kPa remolding pressure with three different confining pressures of about 50, 100 and 150 kPa. Predicted results showed that the soil strength increased with increasing samples' density for those who prepared with a higher remolding pressure. According to the soil composition, a clear decrease in soil cohesion was observed for samples collected at a deeper depth, while a further increase in the effective internal friction angle was observed for samples collected with a lower depth. However, this explains the significant influence of clay contents that can be represented as a relevant relation. Therefore, the results indicated that the studied residual soils have physical and geotechnical properties that are highly dependent on the clay and initial water contents. Then, the concept of long-term stability analysis of hillslope of Balai Cerap area (in UTM/ Malaysia) was presented in the form of factors of safety as discussed later in this study by employing Geo-Studio program (SLOPE/W application) with Limit Equilibrium Method.
Effect of Wetting on Collapsibility and Shear Strength of Tropical Residual Soils
Electronic Journal of Geotechnical …, 2008
Residual soils with extensive weathering of parent materials can yield collapsible soil deposits. In Malaysia, residual granite and sedimentary rock soils occur extensively, i.e. cover more than 80% of the country's land area. These types of soil have a high possibility to collapse when wetted. This paper described a study that had been carried out to examine the effect of wetting on the collapsibility and shear strength of the tropical residual soils. Odometer tests (single and double) and double shear box tests were carried out on selected soil samples. In addition Scanning Electron Microscopic (SEM) test and X-Ray Diffraction Analysis were also carried out. From the result obtained, both types of soils were found to collapse upon wetting (inundation). The finer granitic residual soil (MH) apparently showed a slightly higher collapse potential compared with the relatively coarser sedimentary residual soil (SM). The SEM analysis indicated that the soil structure became more compacted and voids between the structures became smaller upon collapse. The shear strength tests showed that the shear strength of both soil reduced significantly upon collapse, in particular the soil apparent cohesion, with the granitic residual soil showing more strength reduction compared with the sedimentary residual soil.
Effect of wetting on the collapsibility and shear strength of tropical residual soils
2008
Residual soils with extensive weathering of parent materials can yield collapsible soil deposits. In Malaysia, residual granite and sedimentary rock soils occur extensively, i.e. cover more than 80% of the country's land area. These types of soil have a high possibility to collapse when wetted. This paper described a study that had been carried out to examine the effect of wetting on the collapsibility and shear strength of the tropical residual soils. Odometer tests (single and double) and double shear box tests were carried out on selected soil samples. In addition Scanning Electron Microscopic (SEM) test and X-Ray Diffraction Analysis were also carried out. From the result obtained, both types of soils were found to collapse upon wetting (inundation). The finer granitic residual soil (MH) apparently showed a slightly higher collapse potential compared with the relatively coarser sedimentary residual soil (SM). The SEM analysis indicated that the soil structure became more compacted and voids between the structures became smaller upon collapse. The shear strength tests showed that the shear strength of both soil reduced significantly upon collapse, in particular the soil apparent cohesion, with the granitic residual soil showing more strength reduction compared with the sedimentary residual soil.
Numerous shallow slope failures took place in residual soils derived from sedimentary rock formation of Uttaradit province, Northern Thailand in 2005, due to prolonged and intense rainfall. Shear behaviour as well as water retention behaviour of this material has thus been investigated in details in order to investigate the slope failure mechanism. Fully saturated Consolidated-drained (Cd) as well as suction-monitored direct shear tests have been performed on undisturbed samples collected from depths of 0.3-1 m. A miniature tensiometer has been used for suction measurement during these tests. In addition, influence of number of drying/wetting cycles on saturated shear strength is investigated. The results from a simple infinite slope analysis suggest that the major slope destabilization mechanism is a combination of material degradation and pore water pressure increase.
2021
The shear strength of the soil is an important factor to know the internal resistance of soil against external loads causing shearing forces. Shear strength parameters are mandatory for the analysis of load bearing capacity of the soil, the stability of Geotechnical structures and in analysing stress and strain characteristics of soils. The undrained shear strength is one type of shear strength parameter. This parameter is conducted by undisturbed samples. But due to handling, transportation, release of overburden pressure and poor laboratory conditions, it is difficult to obtain accurate undisturbed samples. So, prediction of undrained shear strength parameters (cu) for cohesive soil with the help of compaction characteristics provides a good alternative to minimize this problem. Therefore, this study was conducted to develop the correlation between undrained shear strength values with soil compaction characteristics specifically located in Burayu town. The study was carried out us...