ANALISIS KINERJA TIANG DENGAN VARIASI KEMIRINGAN DI DERMAGA “SJ” BANDAR LAMPUNG

The design of the jetty cannot be separated from the use of piles as a foundation that supports the upper structure. The pile configuration affects the strength and stability of the structure. It may consist of only vertical piles or a combination of vertical and batter piles. This study analyzes and compares 10 types of pile configurations intending to determine the best pile configuration among the types analyzed. Type 1 is a pile configuration that is in accordance with the field planning of “SJ” jetty which consists of only vertical piles and type 2 to type 10 is a pile configuration that consists of a combination of vertical and batter piles with a slope ranging from 1H:12V to 1H:4V. The best configuration is determined based on the strength (capacity ratio), stiffness (deflection that occurs), and the axial bearing capacity of the pile. The process of modeling and analyzing the pile configurations are done using Midas Gen. The results showed that pile configuration type 8 with a combination of vertical and batter piles with a slope of 1H:6V is the best configuration with the smallest deflection and the axial forces of the vertical and batter piles are almost equal.ABSTRAKDesain dermaga tidak dapat dipisahkan dari penggunaan tiang sebagai fondasi yang menyangga struktur bagian atas. Konfigurasi tiang berpengaruh pada kekuatan dan stabilitas dari struktur dermaga. Konfigurasi tiang dapat terdiri dari tegak seluruhnya maupun kombinasi antara tiang tegak dan miring. Penelitian ini menganalisis dan membandingkan 10 tipe konfigurasi tiang dengan tujuan mendapatkan konfigurasi tiang terbaik di antara tipe-tipe yang dianalisis. Tipe 1 adalah konfigurasi tiang yang sesuai dengan perencanaan dermaga “SJ” berupa tiang tegak seluruhnya dan tipe 2 hingga tipe 10 adalah konfigurasi kombinasi tiang tegak dan miring dengan kemiringan 1H:12V hingga 1H:4V. Konfigurasi tiang terbaik ditentukan berdasarkan kekuatan (capacity ratio), kekakuan (defleksi yang terjadi), dan daya dukung aksial tiang. Model dan proses analisis dari seluruh konfigurasi tiang menggunakan program Midas Gen. Hasil analisis menunjukkan bahwa konfigurasi tiang tipe 8 dengan kombinasi tiang tegak dan miring dengan kemiringan 1H:6V adalah konfigurasi terbaik dengan defleksi terkecil serta gaya aksial tiang tegak dan miring yang hampir sama.

A study on the vertical bearing capacity according to the inclination angle of single batter piles and the relative density of sand under vertical loads

This study analyzed the increase in the compressive bearing capacity of single-sloped piles according to the relative density and inclination angle when the batter piles are subjected to a vertical load in non-adhesive sand. An experiment was conducted with inclination angles of 0, 10, 20, 30, and 40, and the relative density of sandy soil was divided into 31% (loose), 53% (medium), and 72% (dense) and compared with the results of the earlier research. As a result of the experiment, when the relative density of the ground was medium and dense, the bearing capacity was greater than that of the vertical pile (0°) at all angles. The tendency noted was that the bearing capacity of the pile increased from vertical to 20° and gradually decreased after 20°. The same tendency was also exhibited by loose sandy soil, but with less bearing capacity than the vertical pile (0°) except for 20°.

Experimental Study on Deformation and Load Transfer Mechanisms of Symmetrical Batter Piles under Vertical Loading

Under the action of vertical loading, batter piles rarely appear individually, as they undergo horizontal and vertical displacements at the same time and produce a sizeable additional bending moment. However, previous studies have mainly focused on a single batter pile, which is inconsistent with engineering practices. Although single pile tests can easily reveal its working behavior, they also ignore two important factors, namely, the internal force redistribution caused by the deformation limitation of the mirror-like pile, and the interaction between the symmetrical piles and “clamped” soil (the soil between two symmetrical piles). Therefore, this paper took symmetrical batter piles as the test object to explore the influence of the two factors on the load transfer mechanism. Moreover, the deformation mode, distribution of inertial forces, and group effect of symmetrical batter piles were also discussed. The results showed that the “clamping effect” caused by the pile deformation had a significant impact on the load transfer. Under vertical loading, the flexible symmetrical floating batter piles were the only deformation mode. Under the constraint of the cap and mirror-like batter piles, the symmetrical conformation partially compensated for the disadvantage of the additional bending moment.

ANALISIS DEFORMASI LATERAL GRUP PONDASI TIANG DENGAN PERKUATAN MENGGUNAKAN TIANG MIRING (BATTER PILES) PADA JEMBATAN DERMAGA

ABSTRACT: Lateral deformation of group piles foundation is one of the parameters that must be considered properly, excessive lateral deformation can cause damage to the structure. In bridge structures, cases of excessive lateral deformation often occur which potentially affect the reliability of the bridge and cause damage to the structure. When the lateral deformation that occurs in the foundation group exceeds the safety limit, it needs additional reinforcement designed to provide additional lateral resistance, so that the deformation that occurs can be reduced and the strength of the structure also increases. Reinforcement using inclined piles (batter piles) can be used in increasing the lateral resistance of the group piles foundation. The use of batter piles mechanically distributes the horizontal load to the vertical direction of the foundation, so that the lateral load that carried by the foundation is distributed into vertical and horizontal components, to reduce the lateral deformation that occurs. In this study, the lateral deformation analysis was carried out on the group piles foundation on the jetty bridge which experienced a large deformation, then a reinforcement design was designed using batter piles to increase lateral resistance. The analysis was performed using PLAXIS 2D and GROUP software. From the analysis, it was found that reinforcement using batter piles can reduce the lateral deformation that occurs and increase the stability of the bridge..Keywords: batter piles, lateral deformation, lateral resistance