cover
Contact Name
Agata Iwan Candra
Contact Email
iwan_candra@unik-kediri.ac.id
Phone
+62811308010
Journal Mail Official
ukarst@unik-kediri.ac.id
Editorial Address
Jl. Selomangleng no. 1
Location
Kota kediri,
Jawa timur
INDONESIA
U Karst
Published by Universitas Kadiri
ISSN : 25794620     EISSN : 25810855     DOI : http://dx.doi.org/10.30737/ukarst
Core Subject : Engineering,
U KaRsT is a journal of the civil engineering research the University of Kadiri published twice a year in April and November. First published in April 2017. U KaRsT already has both ISSN printed and online, for ISSN (Print) is 2579-4620, and ISSN (Online) is 2581-0855.
Arjuna Subject : -
Articles 243 Documents
Improving User Comfort Classroom at the Kalimantan Institute of Technology with Maintenance Factors Oryza L Sari; Bobby Zafnat Fanneah Elwore; Basyaruddin Basyaruddin
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.1615

Abstract

In building construction, the implementation of maintenance activities plays an important role in the quality of the building. By carrying out these activities regularly, it’s hoped to minimize and prevent damage to buildings and make users feel comfortable. Kalimantan Institute of Technology must have comfortable study spaces. This study aims to determine the effect of the class maintenance factor on the user's comfort level. The analysis brought by determining what factors are influencing, these factors influence, and the most dominant factors affecting the most. Primary data was obtained by distributing questionnaires to respondents, secondary data inactive students, and lecturers at the Kalimantan Institute of Technology, and supporting research data in ministerial regulations, books, research journals, and others. The data analysis process uses IBM SPSS as an auxiliary program with multiple linear regression analysis methods. Based on the research and data processing conducted, it’s concluded that 8 factors influence the maintenance, namely the maintenance of user comfort by 80.8% and the variable maintenance of the room walls. The room wall maintenance variable is the most dominant factor influencing the comfort of classroom users. Knowing these factors can implement optimal implementation to support the comfort of class users at the Kalimantan Institute of Technologists.
Reduce Flood Losses Of Kali Tanggul Using Spatial Based Technical Approaches Prabowo Prabowo; Gusfan Halik; Entin Hidayah; Taqiudin Haq
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.1678

Abstract

Flood disasters frequently occurred in Jember Regency, East Java. It is usually caused by the overflow of the Tanggul River in the rainy season, especially in the downstream area. Flood control could be done by building dams, embankments, shortcuts, and other technical flood protections. Meanwhile, mitigation efforts such as developing thematic maps of flood inundation need to be done to minimize losses caused by the flood. This study aims to design a flood mitigation strategy technically. The flood control structure was proposed by designing a shortcut in Kali Tanggul. Its performance was analyzed to reduce flood inundation in the Tanggul watershed. The flood inundation modeling was carried out using spatial analysis using ArcGIS 10.1 and hydraulic analysis using HECRAS 5.0.3. Flood inundation results were compared with the Tanggul watershed flood map developed by UPT PUSDA Lumajang. Based on modeling results, flood control using shortcuts is considered an effective strategy for flood mitigation. It was indicated by the reduction of flood inundation distributions, flood inundation height, and flood-affected areas. The results show that the flood height decrease 0.47 up to 0.56 m
Investigation of Twin Tunnel Deformation with Umbrella Grouting Protection & NATM Tunneling using 3D Finite Element: Case Study Cisumdawu Tunnel Wellyanto Wijaya; Paulus Pramono Rahardjo; Aswin Lim
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.1977

Abstract

Cisumdawu Tunnel is a twin tunnel 472 m long located in Sumedang. Twin tunnel construction can cause additional ground settlement and tunnel deformation. The tunnel construction method used is the New Austrian Tunneling Method (NATM) and umbrella grouting protection system. The principle of NATM is to maximize surrounding soil capacity to support its weight and balance the stresses around the tunnel. Investigation of tunnel deformation is important to know tunnel structure behavior and avoid possible failure. This research aims to know tunnel deformation and the effect of twin tunnel construction on the deformation and ground settlement. The data used such as tunnel geometry, monitoring data, pressuremeter test, and the drilling test. The 3D analysis will be performed for a single tunnel and twin tunnel using Midas GTS-NX, and monitoring data will be used for verification analysis. The 3D FEM help to model the soil condition and construction stage according to the actual condition. The analysis results show the maximum tunnel deformation that occurs from the beginning of the tunnel construction is 12.64cm. If the deformation starts to be calculated following the monitoring reading time, after the excavation at the monitoring point, the maximum deformation of the analysis results is 3.3&4.4cm, where the monitoring shows maximum deformation of 3.3&4.3cm. Through the results, it can be said that the analysis using 3D FEM with pressuremeter test parameter represents actual conditions. Twin tunnel construction side-by-side increases ground settlement and lateral tunnel deformation significantly. Hence, it shows that tunnel analysis using 3D FEM recommends for future investigation of tunnel deformation.
Optimizing Flexural Strength of Concrete Fc’ 14,5 MPa Using Acetylene Welding Carbide Waste Bobby Damara; Sugeng Dwi Hartantyo
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.1998

Abstract

Replacing the main material using unused materials such as hazardous waste can be utilized in concrete innovation. One of the hazardous wastes that can utilize the waste generated from the acetylene welding process. The waste has hardening properties when exposed to water. Its properties are almost the same as cement can replace or add part of the cement mixture. Conducted this research was to determine the effect of using carbide waste from the acetylene welding process on the flexural strength of concrete. The experimental method is carried out by making test objects in the laboratory. The proportions of waste added were 7%, 10%, and 12% by weight of cement. The test object used is in the form of a beam with dimensions of 60 cm x 15 cm x 15 cm. The planned initial quality is concrete F'c 14.5 MPa (K175). The flexural strength test was carried out at the age of 27 days of concrete. From the results of the research carried out, it is found that the use of carbide waste from the acetylene welding process has not been able to improve the quality of concrete significantly. The highest flexural strength was obtained from waste at 7%, with a flexural strength value of 9.692 Mpa. So from these results, it can be used as a reference in the utilization of carbide waste from the acetylene welding process.
Reducing the Risk of Flood Disasters in Lamongan Regency Using the Geographic Information System (GIS) Salwa Nabilah; Nur Azizah Affandy; N. Anwar; M. A. Maulana; N. Nurwatik
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.2079

Abstract

Flood disasters cause negative impacts, such as damage to facilities to the onset of fatalities. Reducing the risk of flooding needs to be done to reduce the impact caused by this disaster. Lamongan Regency is one of the regencies in East Java affected by floods every year in most of its areas. This study aims to reduce the risk caused by flooding by using GIS (Geographic Information System). Mitigation is done by determining areas with a high potential risk of being affected by flooding. The study used spatial analysis functions in ArcGIS. Supporting variables used rainfall, land cover, slope, soil texture, and watershed area, and it becomes important in determining flood-prone areas. From the results, the largest soil classification is the Kpl soil type. Litosol Gray Grumosol, The wide distribution of rainfall from 1500-1750 mm has the widest distribution is 66,67 ha. The slope of 0-8% has the widest distribution of 92,257 ha, making Lamongan a very vulnerable high flood area. Laren District is the District with the greatest flood potential, and Irrigated Field is the dominant land cover type affected by the flood. With the flood disaster map generated from this research, local governments can seek prevention in areas with high flood potential. They can carry out socialization based on disaster mitigation, especially for districts with potential flooding.
Evaluating Liquefaction Phenomenon Of Silty Sand Using Piezocone Penetration Test (CPTu) Albert Johan; Paulus Pramono Rahardjo; Budijanto Widjaja
U Karst Vol. 6 No. 1 (2022): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i1.2118

Abstract

Most investigations into liquefaction have focused on clean sandy soils, with time, evidence has grown that liquefaction is often associated with silty sand material. Sibalaya Village, which suffered the greatest damage from the Palu-Donggala earthquake, is dominated by silty sand material. Related to this issue, an experimental study is conducted in the laboratory to understand the behavior of excess pore pressure and the strength of the saturated silty sand under dynamic loading. The experimental study uses several sets of testing apparatus such as a shake table, chamber, and CPTu. The shake table provides a dynamic load for the soil sample. The chamber allows the field environment to be duplicated in the laboratory. The CPTu measures excess pore pressure and strength of the soil sample. The test results show that liquefaction can occur in silty sand material. However, the fine-grain particles cannot generate the overall pore water pressure in which the pore water pressure ratio can only reach 93% of the initial effective vertical stress. Liquefaction also generates increased pore water pressure and a decrease in soil strength. The increase of dynamic load will result in a shorter liquefaction starting time, and fine content strongly influences the pore water pressure behavior, especially on the rate of pore water pressure dissipation after liquefaction occurs. Therefore, based on this research, it is known that silty sand material can experience liquefaction and can have a longer liquefaction period due to its lower permeability.
Identifying The Impact Of The COVID-19 Pandemic On The Indonesian Construction Sector Using The Exploratory Factor Analysis (EFA) Cecep Kamiludin; Andreas F.V Roy
U Karst Vol. 6 No. 1 (2022): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i1.2147

Abstract

The COVID-19 pandemic has impacted Indonesia's construction sector. The growth of the construction sector severely declined due to the COVID-19 pandemic. However, the study of the impacts of the COVID-19 pandemic on the construction sector in Indonesia is still limited. The present study is aimed to examine the negative and positive impacts (opportunities) of the COVID-19 pandemic on the Indonesian construction sector. The study employed a quantitative approach with 128 contractors and consultants from 34 provinces in Indonesia. Through the factor analysis (EFA) and USG analysis approach, six negative and positive impacts of the COVID-19 pandemic and their priorities can be identified. The six negative impact factors are Workforce issues and Cost Overruns, Financial Performance Degradation, Project completion delays and schedule disruptions, Supply chain disruptions, Legal and contract issues, and  Difficulties in implementing health protocols and adjusting to the standard operating procedure. Meanwhile, the three positive impacts are Increasing awareness of the importance of occupational safety and health and collaboration among stakeholders, Improving the use of technology in the construction sector, and Optimizing existing procedures and systems. The study shows that the pandemic has impacted both the workforce and business entities' business Indonesian construction sector. These findings are expected to be useful in formulating strategic formulation for handling and mitigating the impact of pandemics.
Bearing Capacity Modification Of Clay In The Kedungsigit Village Using Zeolite Krisdiyanto Nugroho; Agata Iwan Candra; Yosef Cahyo Setianto Poernomo
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.2190

Abstract

Clay is a type of soil with a high level of water content. These properties make clay soils have a low low bearing capacity which can have an impact on the buildings above them, such as cracked walls, raised foundations, bumpy roads and so on. The soil in Kedungsigit Village, Karangan District, Trenggalek Regency is clay and needs to be repaired to build a strong building. This study aims to modify the value of the bearing capacity of clay.  Modifications were made by adding Zeolite with a percentage of 0%, 5%, 10%, 15%, and 20%.  Zeolite is used because it contains mineral kristal alumina silikat which have the ability to bind grains between aggregates.  Observations were made on  the characteristics of clay including testing of volume weight, shear strength, and bearing capacity  using the Terzaghi method. The results showed the optimum value for the addition of 15. In testing the bearing capacity of the soil using the tread foundation, the value of 32,470 t/m2 was obtained for the addition of 15% zeolite and 21,376 t/m2 for the original soil.   From these results it is known that the use of zeolite can increase the value of the bearing capacity of the soil. So that these modifications can be used as an effort to improve soil in Kedungsigit village.
Easy Way To Determine The Feasibility Of Coarse Aggregate On All Pavement Layers Using The Los Angeles Tatonas TA-700 Machine Mahardi Kamalika Khusna Ali; Agata Iwan Candra; Elsa Rizqi Purwanti; Rikha Wirda Izzati; Kavindo Yugiswara Hutama; Mohammad Roziq; Herlangga Duta Pramudya
U Karst Vol. 5 No. 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i2.2200

Abstract

The use of coarse aggregate with poor quality can cause bumpy roads, cracked roads, potholes, and others. Coarse aggregate wear is an indicator of the aggregate resistance index against friction with other objects. Any aggregate to be used in a pavement mix must meet the wear requirements. Low wear causes the aggregate to be easily crushed when exposed to friction and has an impact on a low level of stability. The purpose of this research is to determine the feasibility of coarse aggregate in Kedak Village, Kediri. One of the feasibility of coarse aggregate is reviewed based on wear with abrasion testing. This research was conducted by using an abrasion test using the Los Angeles TA-700 machine and SNI 2417:2008 as a reference. The specimens were taken at random and met the criteria for passing the number 3/4 sieve and stuck on the 2500 gram sieve number 1/2 and the aggregate that passed the 1/2 sieve was stuck on the 3/8 sieve as much as 2500 grams. The results obtained stated that the average wear of the abrasion test was 26.6%. Based on these results, the aggregate can be said to be feasible because it does not exceed 40% in accordance with the provisions of the 2018 Binamarga General Specifications. So that coarse aggregate from Kedak Village, Kediri can be used for all mixtures of road pavement layers.
Waste Concrete as a Substitute for Coarse Aggregate Materials for Compressive Strength of Concrete Fc' 20,75 MPa Bobby Damara; Sugeng Dwi Hartantyo
U Karst Vol. 6 No. 1 (2022): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v6i1.2338

Abstract

Concrete from construction waste resulting from the construction of new infrastructure replacing old infrastructure can significantly impact the environment. Therefore, there is a need for the proper management of concrete waste. One of the uses of concrete waste is to use it as a coarse aggregate material in the manufacture of Concrete. Using waste concrete is obtaining a material that almost resembles coarse aggregate. This study aimed to determine the optimum content of Concrete with the addition of waste concrete as a substitute for coarse aggregate. This research refers to the standards of SNI and ASTM. The research was conducted by testing the waste concrete to determine whether it is suitable for coarse aggregate material. After that, the compressive strength was tested by curing for 28 days. This research was conducted with 3 samples with 0%, 50%, and 100% of the planned use of concrete waste with concrete compressive strength of Fc' 20,75 MPa. The results showed that the average compressive strength of the 50% concrete waste was 20.59 MPa, and the 100% concrete waste was 13.83 MPa. From these results, it can be seen that the most optimum content of substituted aggregate is a mixture variation of 50%, so the results of this study can be used as a reference in the utilization of recycled concrete waste as a raw material or a substitute for the composition of the concrete mixture.