Pengaruh Biopolimer Pada Stabilitas Lereng Swelling soil

Many studies have begun to develop the concept of cracked soil. The results of research related to cracked soil are able to answer the irregularities that occur, such as the difference in the results of the stability analysis which is considered safe with the conventional bishop method, while the conditions in the field are landslides. Swelling soil is soil that is susceptible to changes in water content. This type of soil is very prone to cracking. To build infrastructure on the swelling soil type, an improvement must be made, one of which is by mixing the swelling soil with biopolymer. The results of this biopolymer mixing are then modeled in the New Slope Stability Analysis Program (NSSAP) 1.0 which refers to the concept of cracked soil. From the analysis, it was found that the slope safety factor before improvement with biopolymer was 0.305 and the safety factor after improvement with biopolymer was 2.006. From the results of this study, it can be seen that the role of biopolymers in stabilizing swelling soil is quite large, which is around 558%.

Experimental and Numerical Analysis of Soil Cracking Characteristics under Evaporation

There are numerous cracks on soil surface in nature. These cracks are mainly formed by the continuous water loss and shrinkage of soil under evaporation. Cracks have an important effect on the properties of soil. The analysis of soil moisture movement and cracking characteristics under evaporation is of great significance to the engineering construction in the cracked soil area. In this work, an experimental study was conducted to investigate the development of soil cracks. Crack geometrical parameters were acquired at various developmental stages. According to this, the crack evolution characteristic was described qualitatively. The law of soil water movement was analyzed through the numerical simulation of evaporation effect on cracked soil. The relationship between soil moisture content and crack width was revealed, and the dynamic prediction of crack development under evaporation was realized. The results show that the development and evaporation process of soil cracks can be divided into three distinct stages, and the longer the stable evaporation time, the greater the development of cracks.

Risk factors for triatominae infestation in a municipality of Colombia

Background: Identifying risk factors for Triatominae infestation is essential for the development of vector control interventions. Methods: To determine the intra- and peridomiciliary risk factors associated with triatomine infestation, a cross-sectional analytical study was carried out with random cluster sampling in two stages, which included the identification of risk factors by survey and direct observation, as well as the search and capture of triatomines. The detection of trypanosomes in triatomines was carried out by observing the rectal content and then by conventional polymerase chain reaction (PCR). Results: In 21 of the 207 houses inspected, 13 specimens of R. colombiensis and 19 specimens of P. geniculatus were found. Entomological indices included: dispersion 36%, infestation 10%, infection 65%, colonization 4.7%, density 15%, and concentration 152%. An association was found between the presence of Triatominae and the existence of branches and fissures in the floors, as well as with the presence of accumulated objects and with knowledge about Chagas disease. The risk of having triatomines in urban homes is 5.7 times higher than the risk in rural areas [confidence interval (CI) 0.508–67.567]; 6.6 times in houses with cracked soil (CI 0.555–81.994), 6 times in houses located near caneys (CI 0.820–44.781), and 6.16 times with accumulated objects (CI 1.542–39.238). Conclusion: Chagas disease is a complex problem that requires control based on the vector’s elimination or surveillance, which implies identifying species and their distribution, generating alerts, knowledge, and awareness in the population. It is necessary to intensify surveillance activities for the event, especially in changing aspects of Chagas diseases’ transmission dynamics, such as urbanization and the type of housing associated with the vector’s presence.

ENHANCING FURROW IRRIGATION PERFORMANCE AND WATER PRODUCTIVITY THROUGH BETTER DESIGN AND WATER MANAGEMENT IN A CRACKED SOIL

Furrow irrigation is widely used because of its low cost and energy requirement, but less efficient compared with the pressurized irrigation systems. Management of water resources in Vertisols is more problematic compared to other soil groups. This soil is representing a vast crop production resource and account for a considerable portion of the region under study. The preferential flow has a profound effect on the performance furrow irrigation in cracked soils. Accordingly, itis of vital importance to select the most appropriate management practices to improve the performance of surface irrigation in these soils. Accordingly, a series of field experiments were conducted over a cracked soil at a research farm located in the outskirt of Sulaimani city during the summer seasons of 2017 and 2018 with furrow lengths in the range of 30 to 70 m. The main objectives were to improve the performance of furrow irrigation and water use efficiency of eggplant by changing furrow shape and length by application different irrigation techniques. The results indicated that irrigation efficiency tended to increase by reducing furrow length, by decreasing available water depletion and by changing the furrow shape. Overall, the applied irrigation treatments can be ranked according to the degree of their effectiveness in term of irrigation performance, eggplant fruit yield and water use efficiency as follows: Surge flow > Fixed furrow irrigation > Alternate furrow irrigation > Cutback > continuous flow.

Kajian Teknis Penanganan Longsoran Sta. 2+850 - 3+050 pada Pembangunan Jalan Tol Balikpapan Samarinda Menggunakan Bored Pile Metode Plaxis

Construction of the Balikpapan - Samarinda toll road through hilly areas and valley or basin areas. At Sta. 2 + 850 to Sta. 3 + 050 passing through the area it is necessary to reach the finished class required a high level of landfill. Embankment on the Balikpapan - Samarinda toll road construction project has been carried out, but the results are less than perfect so that there is currently damage to the area. Damage that occurred in the form of sinkhole, cracked soil and landslides in the original soil layer / base deep enough to cause the structure of the box culvert that stands on it damaged (box culvert broken and shifted). To improve and to ensure the stability of the structure in the future (box culvert and high landfill), it is necessary to do geotechnical engineering in the form of slope reinforcement technology using reinforcement material (borepile) that is plugged into the ground until it passes through the skid. Technical review of landslides handling at Sta. 2 + 850 to Sta. 3 + 050 using existing soil parameters and modeling using the plaxis program version 8.20. The result of the calculation of landslide handling before the alternative treatment is obtained the total displacement is 0.109 m and SF = 1.139, this shows that the pile of work in the field is still quite critical in terms of design. When reinforced with borepile (either single or double borepile) placed on the berm section obtained a safe number of SF = 1.779 (single) and SF = 1.796 (double), this shows that the number of bored piles is insignificant and the reinforcement is very effective or useful if placed in the berm section. Based on the safe figures obtained, the landslide handling solution uses doubel borepile.