ANALISIS PENERAPAN SISTEM PENJADWALAN DENGAN METODE PERT PADA PROYEK KONSTRUKSI (STUDI KASUS: REHABILITASI DAN PENINGKATAN INFRASTRUKSI PASAR TRADISONAL KOTA MALANG)

PERT is a simplified software, to produce the expected project completion probability based on the duration or duration of a particular contract. In developing the PERT method a lot of research was carried out to perfect this method. The purpose of this study is to determine the overall duration of project completion, the magnitude of the project probability that can be completed in less than 170 days and more than 170 days, and the project completion time with the highest probability. Results of Analysis of Implementation of Scheduling System with PERT Method in Rehabilitation and Improvement of Traditional Market Infrastructure Projects in Malang City is the total duration of simulation results obtained 168 days faster than the 172 day plan. The probability of completing the 168 day project is 50%, while the probability of completing the 172 day project is 85.31%. The highest chance of the project being completed is 99.97%, with a duration of 181 days.

PENGARUH PENAMBAHAN SERBUK BATA MERAH TERHADAP NILAI CBR

Soil is a collection of minerals, organic matter and relatively loose sediments that are located above the bedrock. Based on the particle size, it is divided into four types, namely gravel, sand, silt and clay. The role of soil is very important in a construction because the soil functions as a support for the loads that are above it, so that the soil is expected to have a good bearing capacity. In this study, the soil taken is soft soil in Hambalang, Bogor where the soil conditions in the area are hard in the dry season and soft in the rainy season, so it is necessary to review the CBR (California Bearing Ratio) value. In this study, using waste from red brick as an additive to soft soil. CBR testing is appropriate (SNI 1744: 2012), with the CBR Laboratory test soaked and unsoaked. Along with the addition of% red brick powder, the CBR values of soaked and unsoaked (top and bottom) have increased, so that the addition of% content of red brick powder is 15% respectively got a value of 4.55% and 4.9% (soaked) and 17.94% and 19.70 (unsoaked). So, from this CBR test, it was found that the effect of adding red brick powder increases CBR tilapia soaked and unsoaked soft soil of Hambalang. Keywords: Soft Soil, Red Brick Powder,CBR soaked, CBR unsoaked

INFLUENCE OF INTERNAL LABOR FACTORS ON WORK ACCIDENTS OF XX TOLL ROAD CONSTRUCTION PROJECT

Abstrak The XX Toll Road Construction Project is a national project with high risk and high complexity, given the nature of the work that requires clearing new land on hills and valley areas which requires retaining wall works. During its implementation, work accident occurence can be caused by many factors, including labor factors. This study aims to determine the effect of internal labor factors on work accidents occurred at XX Toll Road Construction Project. The data required in the form of primary data obtained from questionnaires about occupational safety and health, and fitness measurements using the Balke method. The data analysis used Multiple Regression analysis with SPSS. The results showed that the internal factors of the workforce, namely the factors of work safety, occupational health, and workforce fitness simultaneously have strong and significant effect on the occurrence of work accidents in the project. Hence, these internal factors partially bring significant effect. Keywords: labor, safety, health, fitness, accidents

STUDI KELAYAKAN MATERIAL GUNUNG DAERAH ALIRAN SUNGAI ARAH MALANG-KOTA BATU DALAM PENGGUNAANNYA SEBAGAI SALAH SATU MATERIAL BETON

The use of the mountain seal used as a building block for concrete should be considered, based on current usage apart from being a light construction material for housing, mountain materials from these two places are used as the main aggregate material for building construction, water structures (dams), roads. and bridges located in the surrounding Malang-Kota Batu area To determine the size of the aggregate, the coarse aggregate is sieved using a vibrating sieve, while the fine aggregate is sieved by a hydraulic sieve. In the screening process, about 70% of the filtered must pass so that high efficiency and capacity can be achieved. The compressive strength test results obtained the average compressive strength value at 28 days of concrete for concrete with fine aggregate sand zone III and coarse aggregate (gravel) in the Batu City area is equivalent to 35.65 MPa. The results of the split tensile strength test showed that the average split strength value at the age of 28 days for concrete with fine aggregate sand zone III and coarse aggregate (gravel) in the Kota Batu area is equivalent to 2.51 MPa. The compressive strength value for normal concrete is 35.65 MPa, it should produce split tensile strength = 4.179 MPa according to the provisions of SNI T-15-1991-03 Article 3.2.5 (fr = 0.70√fc '). Even though the split tensile strength value obtained in the laboratory is only 2.51 MPa, this means that the quality of materials (sand and broken stone) from Batu City is not suitable for use as building materials. Because the number 2.51 MPa is relatively much smaller than the value of 4.179 MPa, it is only one of the factors outlined in the SNI T-15-1991-03 article 3.2.5. Keywords: Mountain Material, Concrete, Concrete Compressive Strength Test, Concrete Tensile Strength Test

PEMODELAN JEMBATAN RANGKA DENGAN KOMBINASI TIPE RANGKA DITINJAU DARI LENDUTAN DAN BERAT JEMBATAN

The frame bridge structure has several types of frames, each of which has advantages in accordance with its application. Several studies have shown that the comparison between one frame type and another has the advantage of different strengths. In this study an analysis will be carried out by modeling the modified bridge structure truss type and combined with other types to obtain a structure that has the best strengths. The method used in this study is to model the bridge structure with the help of SAP2000 v20 software. The analysis process in this modeling refers to SNI 1725: 2016 concerning load on bridges, BMS (Bridge Management System) in 1992, and several related regulations. The results of modeling analysis show that the K-truss frame is the best frame by looking at the aspect ratio of the bridge, namely the ratio between deflection and weight of each type. The combination of the K-truss frame type and the warren frame type is the best combination of frame types based on the best deflection and weight values. The deflection value for this type of frame combination is -0.416 mm and the ratio value is 6.017. Keywords: modeling, truss bridge, k-truss, combine

ANALISIS ALIRAN BALIK (BACKWATER) PADA AMBANG GERIGI

Gerigi weir is a modificated jigsaw weir which can hold water flow to gain higher water level. This water raising happens in upstream of the weir until certain length to reach normal depth. This research uses square open channel model with slope as an independent variable. In this research uses various slope from 1‰ to 5‰ for eight different discharges. The aim of this research is to find the impact of slope for backwater length using Direct Step Method. The result of this research is the longest back water happened in the 8th of experiment discharge (1399,984 cm3/sec) with the slope of 3‰, by 40.800,4952 cm from the weir. In addition, slope is not affect for the length of backwater. This is because from all analysis of experiments, the longest backwater happens in different slope for each discharge, namely between 1‰, 3‰, or 4‰ of slope. Keywords: back water, gerigi weir, slope

STABILITAS TIANG PANCANG AKIBAT LIKUIFAKSI PADA PROYEK GEDUNG SANGGALA JAKARTA

Liquefaction is an incident where the soil losses its shear strength due to increased porewater stress due to the incident of very fast cyclic loading in a short time. Liquefaction event due to earthquakes can cause structural failure of the building. In this case, the Sanggala Building Project in Jakarta exists at location of liquefaction potential susceptible area, and design analysis only uses the data of Cone Penetration Test (CPT). Stability analysis of pile due to liquefaction potential is aimed to determine the value of the factor of safety (FS) in the area, which is analyzed by comparing the value of Cyclic Stress Ratio (CSR) due to the earthquake and Cyclic Resistance Ratio (CRR) as the soil resistance to resist liquefaction potential. Based on the analysis and calculations performed, was obtained the value of FS > 1, which means actually the soil does not have the liquefaction potential. However, this study still takes into consideration the liquefaction potential as one of requirements of local regulation when the analysis of bearing capacity of pile foundation analyzed by the method of Schmertmann (1978) in a depth of 25 m and the results was indicated by 1660,27 kN for single pile and 12081,63 kN for the group piles. Furthermore, all these results from several stability calculations, the pile foundation system stable from liquefaction potential.

SIMULASI POLA OPERASI EMBUNG SERBAGUNA TAMBAKSARI KABUPATEN CILACAP DENGAN METODE STANDARD OPERATING RULE (SOR)

Human survival depends on water availability as water is a basic needs. As population increases, water becomes more limited. One of the ways to prevent draught is collecting water in retention basin. Tambaksari Multipurpose Retention Basin serves to provide basic water demand and irrigation water for the local community. Water availability and water demand should be equal, so a simulation of the operating patter of the retention basin is necessary to distribute water equally and determining the failure level of the retention basin in performing its task. In the present study, the retention basin operating pattern was simulated using Standard Operating Rule (SOR) method. The present study used secondary data, including population data, rainfall data, climatological data and technical data of the retention basin. The size of DAS Tambaksari is 0.41 km² while the size of the irrigated land is 12 Ha. The rainfall data was from 2008-2018 obtained from two rain stations, population data of Tambaksari Village was from 2008-2019, and the climatological data was from 2014-2019. The simulation result of the retention basin operating pattern using SOR method showed that the final collection wasn’t under minimum collection and failure happened in the operation of the retention basin for one year. . The optimal ability of the target release is 70.83% for the reliability of irrigation needs and the level of reliability for raw water needs of 58.33%. Population projection analysis to determine the population in 20 years showed that the future population of 4044 required 3.861 l/person/s of water. Irrigation demands for rice-rice-palawija planting pattern showed that irrigation intake was 11.89 l/s. Water balance determined the balance between inflow and outflow. The value for average water availability was 0.021 m³/s while total average water demand was 0.016 m³/s. therefore, the water availability in partial intake wasn’t able to meet the irrigation and basic water demands. Keywords: discharge, retention basin operation simulation, SOR

EVALUASI NON-PHYSICAL WASTE DENGAN LEAN CONSTRUCTION PADA PROYEK GEDUNG SANGGALA

The construction industry faces many challenges with problems related to construction waste as it takes up time and effort without adding value to clients. A concept in project management, namely lean construction, has the main focus of minimizing waste and providing added value to a construction project. The purpose of this study was to know the existence of non-physical waste, its causative factors, and how lean construction can be implemented to minimize non-physical waste in earthworks, foundations and basement 2 of the Sanggala Hotel and Office Building Project. The study was carried out by observation, document study, and questionnaires to identify non-physical waste. This study showed that the non-physical waste that most often occurs in related project was equipment breakdown frequently with a weight of 0.086. Meanwhile, the non-physical waste variable that has the greatest impact on causing time overrun on the project was delayed schedule with a weight of 0.080. Equipment breakdown frequently is influenced dominantly by the equipment shortage. Delayed schedule is influenced dominantly by licensing problems. In general, lean construction approaches such as Construction Meetings, Preventive And Predictive Maintenance, and Fail-Safe For Quality And Safety can be applied by contractors to minimize non-physical waste that was dominant in the project. Keywords: Lean Construction, Non-Physical Waste, Waste

KUAT TEKAN BETON CAMPURAN GGBFS DAN FLY ASH MENGGUNAKAN RETARDER

One of the world's construction needs is casting in large volumes that require concrete with low hydration heat, and one of the problems is that the concrete has a setting during the casting queue. Therefore, a research was conducted on adding retarder to concrete with a mixture of GGBFS and Fly Ash. The purpose of this research was to analyze the physical and mechanical properties of concrete, the effect of adding retarder and obtain optimal retarder levels. This research used an experimental methods to make concrete specimens of 75% cement mix: GGBFS 15%: Fly Ash 10% with a water cement ratio of 0.5 using mix design SNI-03-2834-2000. Variations of the retarder added to the concrete mixture were 0%, 0.2%, 0.4%, and 0.6% by weight of cement with the Naptha RD 31 type. Analysis of the effect of the retarder used statistical regression test methods on SPSS. The results of research obtained the longest setting time in this researchwas 1890 minutes at a variation of 0.6% with a slump of 168 mm. The compressive strength of the concrete increased by 12.07% - 52.36% by using a retarder added material. Based on the research results, it was obtained that the optimum level of use of retarder in mixed concrete GGBFS and Fly Ash was 0.2% because it has the best physical and mechanical properties. Keywords: Fly Ash, GGBFS, Compressive Strength, Retarder