Papers by Keyword: Settlement

Abstract: Foundation engineering has large challenges with weak and loose soil, especially sandy soil, which has low shear strength and high compressibility. as known used pile raft to reduced excessive settlement, differential settlement, and to increase bearing capacity of the soil to carrying the loads from super structure. The benefit of use combined (raft piles) to improved load distribution and, increase bearing capacity and enhance stability. It is depending upon many influencing factors the load distribution mechanisms, the pile number, the space between piles and on the pile position. Geopolymers are inorganic formed by the reaction of aluminosilicate materials with alkaline activator. To produce geopolymers, two essential conditions must be fulfilled: the presence of source material abundant in Silicon (Si) and Aluminium (Al), and the addition of an alkali activator, such as sodium/potassium hydroxide..it has several advantage than other traditional soil stabilization method, which increased the soil's load-bearing capacity, enhance the soil properties. This study aims to review the studies of previous researchers and their practical and theoretical findings regarding the use of geopolymers as stabilising agents and pile raft to improve the soil's resistance properties.

Abstract: In a laboratory setting under consolidation conditions, this study investigated the performance of saturated silty sand improved by stone columns. The studies were carried out with area replacement ratios of 0.03, 0.06, and 0.11, and relative soil densities of 40% and 90%. The properties of the stone column were analyzed by measuring settlement and stress distribution on the soil and column. The performance improvements are mainly due to the stiffness and high bearing capacity of silty sand under dry conditions. However, when in contact with water, there is a high risk of failure because the soil becomes saturated or partially saturated. The soil transitions from a solid to a liquid state, resulting in a loss of strength and stiffness under applied vertical pressure. The test results displayed that the settlement reduction ratio of the stone column ranged from 1.12 to 2.18. The stress concentration ratio ranged from 5.04 to 6.78, and column efficacy ranged from 0.126 to 0.459. Thus, the stone column significantly improved the silty sand by decreasing settlement, increasing stress on the column-supported embankment, and reducing stress on the soil.

Abstract: Land disputes that often occur in Indonesia are disputes over land rights. Disputes over land rights occur in many places throughout Indonesia, both in remote villages and urban areas. Most of the problems that arise are related to land cases in the plantation sector. The case of land disputes in the plantation sector was caused by a sharp socio-economic gap between plantation entrepreneurs and residents living around the plantation area. One of the land rights disputes occurred between PT Selatan Agro Makmur Lestari (PT SAML) and residents of Tirta Mulya Village, Air Sugihan District, Ogan Komering Ilir Regency, South Sumatra Province. The research method used in this research is the descriptive qualitative method. Data collection techniques are by means of interviews, observation, and documentation. The findings in this study were that in 2017, Komnas HAM RI successfully mediated mediation. Still, the results of the agreement failed to be implemented. Hence, in 2020 the residents of Tirta Mulya Village made another complaint to the Regional Land Office of South Sumatra Province because they rejected the results of the agreement signed by representatives of residents who did not give the power to represent the residents of Tirta Mulya Village. The recommendation of this research is to create an effective mediation model such as good communication, fairness in making agreements, integrity and good will from all parties.

Abstract: Comparative results of settlements of soil-cement soil bases of multi-story residential buildings determined by the methods of linear soil mechanics, finite element modeling in a planar (2D) and spatial (3D) setting using an elastic-plastic soil model, as well as long-term (over ten years) data of geodetic observations of natural objects are given. The object of this work was to evaluate the reliability of various methods of predicting the settlements of soil-cement soil bases of buildings on strip foundations in the presence of weak soils within the compressible soil thickness and reinforcement of the massif to a depth smaller than the width of the foundations. It was established that in the presence of layers of weak soils within the compressible soil thickness under strip foundations and reinforcement of the massif to a depth less than their width the actual settlements of such soil base exceeds the values allowed by the norms. The scientific novelty of the work is it was determined in the first time that under these conditions the methods of linear soil mechanics underestimate the calculated settlements by more than two times compared to their actual values. On the other hand, the high reliability of the use of mathematical modeling methods using the elastic-plastic soil model has been proven.

Abstract: This study employs 2D finite element modeling using Plaxis to investigate the behavior of the railway embankment constructed on the active Ganges-Bramhaputra floodplain. The parametric study considers three different train speeds, 100, 120, and 170 km/hr, and two different soil profiles along different chainages, chainage 82 km+183 m (Ch1) and 84 km+102 m (Ch2) of Padma Bridge Rail Link. Pseudo-static trainloads have been applied and the settlement of the ballast bottom (BB) and embankment bottom (EB) have been determined and compared along with the factor of safety (FS). From the obtained results, the maximum settlement of EB in Ch1 ranged between 27.45 cm to 29.2 cm which is lower by 9.2 cm from Ch2 on average. For BB, greater settlements have been observed as they varied between 33.25 cm to 36.20 cm for Ch1 and 42.80 cm to 45.31 cm for Ch2. Thus in both cases, Ch2 shows greater settlements. Also in both chainages, the settlements exceed the allowable range. As the train speed increases from 100 to 170 km/hr, the increase in the settlement is noticeable for the ballast bottom but not for the embankment bottom. Considering the FS, the embankments are assessed to be safe in all considered cases with an FS> 1.2, without any significant effect of train speeds.

Abstract: Currently there are different techniques of soil improvement. One of them is the gravel columns that is one of the most popular and profitable techniques for soil improvement. This method of breeding increases the physical and mechanical properties of the soils. However, it has limitations, because part of the aggregates in non-specific areas can generate settlement that affects the structure. In this study, it reduces the settlement of the gravel column by making a change in a certain percentage in its structure by a concrete that is not reinforced. Different heights of the concrete are visualized, in addition to having different variants such as columns that are next to the base, as well as the columns that are on the sandy ground. The research was carried out with the simple compression machine with the concept of unit cell. The yield of the hybrid columns (gravel and concrete) had a better yield which was 20% compared to the traditional gravel columns.

Abstract: Flexible pavement failure has been a major problem encountered in various countries. Some common distress which had been listed are cracking and rutting. The causes of this distress are due to moisture, weak sub-grades and poor construction quality. High amount of distress in the pavement however is likely to cause dis-comfort for the passengers, higher accident rate and heavy traffic. Study suggested that, flexible pavement failure can be reduce, through maintenance of the wearing course of the pavement, improving the base, sub-base layer or the sub-grade soil underneath of the pavement. However, high production or material cost, high construction cost, excessive settlement, or weak inter-molecular bonds in the flexible pavement are some of the common problem encountered with the current improvement techniques. This significance difference of this review paper compare to other is that, in this review paper it focuses on the flexible pavement failure, the different types of improvement method currently applied. Consequently, it further recommend flexible pavement improvement method through by reducing the sub-base layer thickness and inclusion of light weight material in the sub-base layer so that, the settlement of the pavement is reduced.

Abstract: Improving the reliability and durability of sidewalks, footways, car parks and areas for various purposes, made of concrete paving blocks (CPBs), is an important task of construction. In order to improve the quality characteristics, new pavements consisting of concrete paving blocks with a ribbed underside surface are proposed. Hypotheses about the advantages of the developed structural solutions of pavements relative to traditional pavements of blocks with a flat underside surface were formulated. To confirm the hypotheses, studies of one of the developed pavement variants of in laboratory conditions were performed. The article describes the plan and methodology for implementation two series of experiments. In the first series of the experiment, a section of a traditional pavement of concrete blocks with a flat underside surface was investigated, in the second, a section from a pavement of concrete paving blocks with a ribbed underside surface consisting of three prismatic elements. Qualitative characteristics of the pavement are determined by various indexes. As a result of laboratory tests, the dynamics of settlement of experimental CPBs under the influence of vertically applied load was studied, and density index of a sand structural layer located under the tested CPBs was also obtained. The settlement indexes of the tested CPBs were investigated for three days. A comparative analysis of the experimental results confirmed the hypothesis about the advantages of pavements of concrete paving blocks with a ribbed underside surface. For the further implementation of the developed pavement variant in the construction industry, additional research is required. Further research directions of pavements of concrete paving blocks with a modified geometric shape of the underside surface are determined.

Abstract: Stone columns have been used widely to improve the engineering properties of the weak soil. Most of the previous works considered a circular section for the stone columns. In the present study, finite element analysis has been carried out to investigate the effect of stone columns shape and length on the settlement and bearing capacity of soft soil. Accordingly, three types of cross sectional shape for stone columns have been selected which they are circular, rectangular, and square sections with equivalent area. Various length of columns are adopted with diameter of 0.75m that achieved length to diameter or equivalent diameter ratios (L/d=2, 4, 6, 8, and 10) of columns spacing (S/d=3). The results show that the stone columns has tangible effects on the settlement of the soil while has minor effects on the bearing capacity. The settlement of the treated soil with stone columns have L/d=2, reduces by 18.0, 17.3, and 19.3% for circular, rectangular , and square sections respectively. With increasing length of the columns to L/d=10, further reductions in the settlement obtained of (27.1, 28.1, and 27.0%). Bearing capacity of the soil increased slightly with length of the stone columns. Almost all cross sectional shapes of the columns give bearing capacity about same. The increased in the bearing capacity of the treated soil with stone columns have L/d=2, not exceeded 10% for all sectional types. The average increments in bearing capacity when L/d=10 are 12 and 15% at settlement 50 and 100mm respectively. Insignificant changes in bearing capacity upon increasing length of columns from L/d=2 to 10 of maximum 5%. The plastic zone recedes with the increasing length of the stone columns. Finally, from the results obtained, it can be concluded that the stone columns shape has negligible effects on the settlement and bearing capacity of the soil.

Abstract: Gypseous considered as problematic soils also gypseous soils are distributed all over the world, as well as in large areas of Iraq, including Al- Najaf city. Gypseous soils are characterized by high strength in dry conditions, but they collapse due to water infiltration process under constant head conditions. In this research, a field study investigates gypseous soils and the effect of soaked state on the bearing capacity and settlement of the gypseous soils are investigated. A site with a high percentage of gypsum (about 25%) was selected to perform plate load tests. The test was carried out in a natural and soaked state on the gypseous soils by plate load test with time-dependent. The results show the ultimate bearing capacity of gypseous soil from plate load test are decrease under the soaking condition and maximum settlement increase. The angle of internal friction (ø) of gypseous soil we obtained from the direct shear test is 47.62⁰ for natural soil. The ultimate bearing capacity of gypseous soil was calculated from the Terzaqhi’s equation and the high difference between field tests and theoretical results.