Wong Foek Tjong

APLIKASI STATISTIK EKSTRIM DAN SIMULASI MONTE CARLO DALAM PENENTUAN BEBAN RENCANA PADA STRUKTUR DENGAN UMUR GUNA TERTENTU

This paper presents the results of an experimental evaluation between predicted and practice concrete strength. The scope of the evaluation is the optimisation of the cement content for different concrete grades as a result of bringing the target mean value of tests cubes closer to the required characteristic strength value by reducing the standard deviation.

STUDI EFEKTIFITAS PENGGUNAAN TUNED MASS DAMPER PADA STRUKTUR GEDUNG DALAM MEREDUKSI RESPONS DINAMIK AKIBAT BEBAN SEISMIK

The using of Roller Compacted Concrete (RCC) is one of many alternatives that can be used to decrease dam construction cost. Many Roller Compacted Concrete (RCC) composition has been developed to achieve maximum compressive strength. Due to the economical consideration and the possibility of the execution, drop hammer system has been used for this research. Compression test is done after the age of the sample reaches seven, 28, 60, and 90 days. The result shows that 60/40 composition of gravel/sand has higher average compressive strength on all age of sample. The highest compressive strength the achieve is 17.78 MPa for 90 days sample.The slake-durability test is regarded as a simple test for assessing weathering of rocks. This simple test has been accepted as a standard test by the Rock Mechanics Society. However, mechanisms into slaking processes have not been fully understood yet as many factors involved in the processes. The current research explored mechanisms performed by the test by conducting a series of slakedurability tests for four types of soft rocks taken from Coober Pedy, South Australia. Results show that the slake-durability index (Id2) of weathered soft rocks was influenced by the degree of weathering. Distinctly weathered rocks had lower indeces compared to partly weathered rocks. Shapes also influenced the Id2 of these soft rocks. Different shapes displayed different mechanisms in the slaking processes. Samples that had irregular shapes tended to have a lower Id2 compared to samples that had rounded shapes. Thus, the slake-durability test might have simple procedures, but it could have complicated mechanisms in slaking processes that contribute to the result of the test.A method commonly used to stabilize expansive soils is mixing the soil with foreign materials. The main obstacle raised from soil stabilization in the field is the difficulty in mixing process. This paper presents the strength distribution in soft soil due to the addition of single columns of quicklime and carbide wasteproduct from gas industry that contains Calcium Oxide (CaO) up to 60%. The results show that the addition of columns filled with carbide waste product and quicklime increase the shear strength of surrounding soil. The spreading of the strength tends to follow a unique pattern, that the increase of soil shear strength at a certain normalized-distance, S (in column diameter D) from the column axis is constant. A significant increase of strength occurs in the area closer to the column, and it decreases with the distance from the column.

APLIKASI KONSEP BERBASIS PERPINDAHAN PADA PERENCANAAN PILAR BETON BERTULANG UNTUK STRUKTUR JEMBATAN

In recent years, meshless methods have been developed as alternative numerical approaches in efforts to eliminate known drawbacks of the Finite Element Method (FEM). The main objective in developing meshless methods was to eliminate, or at least reduce, the difficulty of meshing and remeshing of complex structural elements. The nature of various approximation functions employed by meshless methods allows the definition of problem domains by simply adding or deleting nodes where desired. Nodal connectivity to form an element as in FEM method is not needed, only nodal coordinates and their domain of influence (DOI) are necessary to descretize the problem domain. Meshless methods may also reduce other problems associated with the FEM, such as solution degradation due to locking and severe element distortion [1].