4.2 Project Works Activites
4.2.2 Bridge Work
Bored pile foundation is a type of deep foundation that has a shape like an elongated tube consisting of a mixture of concrete with reinforced iron with certain dimensions and diameters that is installed in the ground using the drilling or excavation method with the installation of iron installation and
Figure 4.1 Excavation Drawing Shop
35
35
concrete casting on the spot. The length of the bored pile foundation must arrive at a depth with the hardness level of the soil carrying capacity required for the basic foundation of building construction. Bore pile foundations have the same function as pile foundations or other deep foundations. The difference between the two is in the way the process is executed. The implementation of the bore pile foundation begins with making a hole in the ground by drilling the soil first then installing reinforcing iron into the hole followed by casting the drill pile with tremie.
The bearing capacity of the bored pile is obtained from the end bearing capacity which comes from the pile tip pressure and the friction bearing capacity which comes from the friction bearing capacity or the adhesion force between the bored pile and the surrounding soil.
Pile foundations, including bored piles, are usually used on soils that are stable and stiff so that it is possible to form stable holes. If the soil contains water after the soil is perforated with a drill, an iron pipe is needed to hold the walls of the hole and then the iron pipe is pulled up when the concrete is poured.
Whereas on hard soil or soft rock, the base of the pile can be made larger in order to increase the bearing resistance of the end pile.
4.2.2.2 Pile Cap
Pile Cap is the superstructure after Bored Pile and before column work.
Pile Cap serves to withstand the overturning force on the Pier and serves to spread the load from above into the Bored Pile foundation. Pile cap is a site
Figure 4.0.1 Bored Pile Sangu Banyu Construction
36
36
which is usually made of reinforced concrete beams which serves to unite a group of piles and spread the load from the structure above it. Because the role of the pile cap is very important, the method used and implementation in the field are decisive in making it happen. This implementation study aims to analyze the method of implementing pile cap construction, the use of tools and materials, as well as the quality control of reinforcing steel and concrete in pile cap construction. The implementation of pile cap construction is guided by the pile cap structure method, the fabrication method and the cast method that have been planned for the project. The implementation in the field consists of excavation work with excavators and workers, cutting pile heads, installing brick formwork, making work floors, reinforcement and casting. The results of field observations were analyzed by means of comparison with the theories and methods. The results of the analysis study on the implementation of the pile cap construction work are in accordance with the theory and the planned methods.
The use of tools and materials in the implementation of pile cap construction is in accordance with the schedule and needs.
The implementation of quality control of reinforcing steel and concrete is carried out in accordance with the required grooves and in accordance with the specified quality specifications. Pile caps are used to bind the already installed piles. The planning of pile cap dimensions can vary depending on the number of embedded piles. The function of the pile cap is to receive the load from the column which will then continue to be distributed to the piles. Pile cap is one of the important elements of a structure. This is because the pile cap has an important role in distributing the structural load to the piles to then be passed on to the soil. Pile caps are used as a foundation to bind the installed piles to the structure above them. The purpose of making a pile cap is so that the location of the column is really at the center of the foundation so that it does not cause eccentricity which can cause additional load on the foundation. In addition, like the column head, the pile cap also functions to withstand shear forces from the existing loading.
37
37
4.2.2.3 Box Culvert
Box culverts are reinforced concrete structures that are often used as culverts and underpasses in several parts of Indonesia. Most of the functions of box culverts are indeed for large-sized drainage channels, but currently box culverts are also often used as underpasses on toll roads with very large sizes.
Almost all box culvert structures have a rectangular cross-section with a hole in the middle. There are two types of box culverts that are often used, namely Precast and cast in situ. So that between the two types have different methods of carrying out the work. Precast box culverts are usually small in size and are used for culverts or drainage channels. Meanwhile, the box culvert cast in situ structure is usually large in size for vehicle underpasses.
Box Culvert is a building built under a road or bridge that is used as a connecting line such as a road, water channel (drainage), gas pipe, and so on.
Basically Box Culvert is a construction that resembles a square or rectangular
"pipe" made of reinforced concrete which has relatively low tensile strength and concrete ductility and is offset by iron reinforcement which has a higher tensile strength. This box culvert uses the cast in situ method. The following is the process of making Box Culvert:
1. Box Culvert Reinforcing
Figure 4.3 Pile Cap
38
38
2. Casting process the bottom of the box culvert 3. Casting process box culvert wall
4. Reinforcement of top and wingwall box culverts
Those are some of the execution of box culvert work in situ cast. Usually in the execution of work, concrete samples of cylinders or cubes will be taken for quality testing. This quality test is very important, especially for the box culvert cast in place method. As for box culvert precast, there are lab results from the batching plant.
Figure 4.2.2.3.1 Box Culvert STA 75 + 399 Figure 4.4 Box Culvert STA 75 + 399
39
39