Lawalenna Samang

Experimental Study of Moving Truck Emissions on Inter-City National Road: A Case Study of Malino Main Road

The research aimed to determine exhaust emission and speed of the truck when moving. Measurements were made using a mobile emission analyzer that absorbed emission from truck exhaust. Data collection was done by putting mobile emission analyzer on the right side of the vehicle which absorbs 5 emissions of approximately 5 minutes. The relationship of exhaust emission and speed uses the polynomial model of the average value of exhaust emission and speed. The reliability of mobile emission analyzer uses the multiplier factor to solve the data difference between mobile emission analyzer and Bosowa equipment. The results of research indicate emission of CO2, NOx, Smoke, CO, and HC forming driving cycle pattern. This pattern shows the pattern follows parabola tendency. Emission on damaged road is higher than good road although the emission values are not much different. However, the value of emission of Smoke is relatively equal in both road conditions.

Experimental Study of Clay Stabilization with Quick Lime Activated by Gum Rosin and Iron Oxide

This study is intended to increase the bearing capacity of expansive clay as subgrade of highway. Compressive strength of compacted original soil is 0.27 kg/cm, and laboratory CBR value (unsoaked) is 8.9%, therefore carried out stabilization with quicklime, activated by gum rosin and iron oxide. Design mix composition resulting proportions on weigh, 100 quick lime : 10 gum rosin : 8 iron oxide which is then named KA for stabilizers. Samples are made with variation KA 5%, 10%, 15%, and 20% of the dry weight of the soil, and then tested with UCS, CBR, and Hydraulic Compressibility. Test results show that soil + 20% KA at 28 days curing, the UCS value is 117.78 kg/cm. On 7 days curing, soil + 5% quicklime obtained CBR value is 14.82%, and soil + 5% KA obtained CBR value is 45.06% (increased by 300%). Hydraulic compressibility test result show that the soil sample is impermeable. The activation of gum rosin and iron oxide improve the performance of lime on soil stability significantly, so that the expansive clay achieve technical specification as subgrade of highway.

Numerical Modelling of Reinforced Stone Columns and Bamboo Mattress for Supporting Causeway Embankment on Soft Soil Bed

This paper presents numerical model of reinforcement of causeway embankment over soft soil deposit using bamboo grid mattress and stone columns. A series of experimental tests were undertaken to obtain several mechanical parameters of stone columns, and mechanical characteristics of bamboo grid. The soft soil is silty clay in deep layer in which its index and engineering properties derived from oedometer tests. FEM model of a causeway embankment over bamboo grid mattress overlying deep soft soil reinforced by a group of granular columns encased with geotextile, was developed. To validate the FEM model, full scale experimental of similar model was conducted. It was found that FEM model is well agreement with the experimental model. The result explains the stress-strain behavior in bamboo grid mattress and stone columns, interacted with the soft soil as response to increasing embankment height. Bamboo grid mattress enhances the bearing capacity of the soft soil in supporting embankment leading to the decrease of settlements, while stone columns affect the acceleration of consolidation of the soft soil. The results would be beneficial for application of local natural materials such as bamboo for soft soil reinforcement as bamboo is widely available in developing Asian countries.

WEATHERING STAGE CONTROL OF TUFF AND ITS INFLUENCE TO THE MALINO–MANIPI LANDSLIDE SUSCEPTIBILITY, SOUTH SULAWESI INDONESIA

In 2013 there has been 34 incidents of landslides which cut the roads linking between Gowa and Sinjai off. The purpose of this study was to determine the effect on the stage of weathering of landslide in the study area. Methods used in this study are field survey, petrographic analysis, XRD analysis and shear strength testing of rock. Field survey results indicates that the area is dominated by tuffs that are partly volcanic breccia and lava. Petrographic analysis, showing the dominant composition of tuff with volcanic glass, bitownite, pyroxene and opaque minerals, and XRD analysis results indicate weathering tuffs that have experienced high and completely weathered contain smectite and halloysite clay types, and insitu shear strength test results indicate a strong shift to the lower tuff with high stage of weathering. Keywords: Susceptability to landslides, the stage of weathering, halloysite and smectite, shear strength, roads of Malino–Manipi

Statistical Analysis of Dynamic Bearing Capacity of Driven Pile

This paper presents the use of statistical-probabilistic method in determining pile bearing capacities over a number of driven piles. Four dynamic formulas were employed to estimate pile bearing capacity including modified ENR, Hiley, Navy – McKay and Danish. We investigated the final setting data of 47 concrete piles with 600 mm diameter in the construction projects of New Naval Engineering Building Hasanuddin University. Based on the data, pile bearing capacity were computed and then analyzed statistically. Goodness of fit with Kolmogorov-Smirnov and Shapiro-Wilk were used to fit the probability distribution function (PDF) of the pile bearing capacity data to the PDF model. It was found that the pile bearing capacity estimated using ENR is more uniform with 506 tons average pile capacity and 6.4% COV, while that with Hiley and Danish are less various with 252 tons and 346 tons average pile capacity, and 14.7% and 16.6% COV respectively. Navy-McKay was found to have 465.8 tons average pile capacity with higher variability of 44.08%. A 90% Probability of pile bearing capacity estimated by ENR is 535 tons, or 1.17 times the upper bound, and 1.4 times the lower bound of pile capacity measured by pile driving analyzer (PDA). In comparison, 90% probability estimated by Danish is 420 tons or 0.93 times and 0.92 of the upper and lower bound of pile capacity measured by PDA, respectively. The Navy-McKay seeems to be overestimated whereas Hiley is underestimated.

APPLICATION OF CEMENT STABILIZATION SEDIMENT DREDGED AS SUBGRADE ROAD OF RIGID PAVEMENT

On march 26, in 2004, some areas of mount Bawakaraeng landslide, carrying an expected avalance of material about 230 million cubic meters of sediment in the upstream, due to the effect on the future ruins of multi-purpose reservoir located Bili-Bili +30km downstream from caldera. There are around 75 million cubic meters of fine sediment that had accumulated in the bottom of reservoirs and nearly reaches the intake. Therefore, the effort is needed in order to maintain the stability of sediment dredging reservoir function. The purpose of this study is examine the behavior of sediment dredging Bili-bili dam with cement stabilization for rigid pavement and give solutions to optimize the bili-bili dam function in a way to dredge the sediments around the intake dam, but the impact on the accumulation of material (material dumping) and damage the environment. While the other parties would need the land for road construction is increasing, but the soil is limited and expensive. By looking at the problem, this study tries to make an assessment of sediment dredging to be used as a soil base (subgrade). The improvement of the sediment was conducted with a number of tests such as physical tests, chemical, and minerals to determine the characteristics of actual dredging sediment continued with stabilization of the soil sample, namely mixing with cement binder percentage and curing time, and then conducted laboratory tests to look at mechanical index. Results of laboratory tests were then conducted the test model with rigid pavement loading, to find a large decline in sediment material from the subgrade, cement stabilization of loading, the result of the analysis in the form of graphs the relationship between the moduls of subgrade reaction (k) with some of the CBR as a model validation data.