Formwork is a temporary concrete mold that holds the concrete from fresh concrete until the concrete reaches sufficient strength. Besides the strength and easy to implementation, the cost of formwork is important thing to consider. In this study, the cost of column, beam and floor slab formwork will be analyzed by comparing the  conventional formwork and system formwork on the 1st floor of the IAIN Bukittinggi Laboratory Development Project. This research begins by collecting the main data, namely shop drawings so that the volume and also cost of formwork can be calculated. For analysis conventional formwork using the unit price analysis based on the PUPR Ministerial Regulation 2018, but for price of materials and worker wages based on the Bukittinggi area in 2019. While for system formwork, the rental price based on formwork and scaffolding company, PT. Wijaksana Perkasa Beton. The result of this study indicated that for the 1st floor of the Laboratory Development Project of IAIN Bukittinggi, the cost of system formwork is more expensive than conventional formwork, i.e Rp 381,260,039.29 for system formwork compared to Rp 336,629,299.41 for conventional formwork. The results of this study also have not compared of the speed and ease of carrying out the work between the two types of formwork which will be investigated in the next stage.

Construction projects have a very high risk of work accidents. Work accidents will disrupt all project activities that can cause death and loss to the project. A work accident is an undesirable and unexpected incident which could result in loss of life and property. Based on Law No.1 of 1970 concerning work safety, work accident is an unexpected and undesirable event that disrupts the regulated process of an activity and can cause harm to both human victims and property. For this reason, it is necessary to have a construction safety management system using methods Hazard Identification Risk Determining Control (HIRADC). HIRADC will be implemented if there is support from management for occupational safety and health (OSH) in the form of policies, organizational structure and budget. From the studies conducted, the most common hazards are falling, punctured, scratched, tripped, bumped, inhaled dust, electric shock, exposed to concrete splashes with extreme risk of risk of injury, disability and even death. For this reason, there is a need for handling control in the form of mandating the use of PPE, administrative control such as making work instructions, SOP, must have SIO and SILO, installing signs, and doing engineering such as work methods, shopdrawing, providing regular training.

Soil stabilization by adding new materials is one of the alternatives to soil repair that can improve the properties of the soil, namely by mixing new materials and soil that is then compacted. Waste left over limestone hill mining,among others in the form of materials with various sizes of granules. This study aims to review the effect of the addition of limestone hill mining waste material on the density and value of the California Bearing Ratio (CBR)  of clay soil. Tests conducted only on a laboratory scale with variations in the increase in limestone hill  mining waste levels are  0%, 5%, 10%, and 15% to the total weight of the mixture. Laboratory CBR testing is performed under optimum water content conditions. The results showed that the stabilization of soft soils using limestone hill mining waste, can increase the density and value of soil CBR. The most optimal level of use of limestone hill mining waste and which provides the highest CBR value is for the addition of  5%of limestone hill mining waste with a CBR value of 26.5%.

Earthquakes that occur in buildings can lead to collision force with the next building if the initial gap between the two buildings is not sufficient for its free vibration responses. Collisions can cause amplification of the internal forces in the structural elements and the collision force on the contact zone is usually not considered in the initial design so that it can lead to damage and collapse of buildings. This study aime to determine the effect of Soil-Structure Interaction in the dilatation of two structures in soft soil with consideration of the collision to the next building. The structure is modeled as a structural system with multi degree of freedom (MDOF). The upper structure is considered linear elastic model and does not have damping as well as the lower structure (foundation). The collision can only occur on the floor level of the two buildings in which the contact zone is modeled as an elastic element. The rheological model for Soil-Structure Interaction are taken as a horizontal spring and a rotational spring. Structural dynamic equations was solved by using the Houbolt integration method. The resolution of numerical program was solved by the Matlab software. The results of study showed that soil-strucutre interaction increases the relative displacement under the condition of initial distance (gap) between the two buildings was reduced.