ANALISIS STABILITAS DINDING PENAHAN TANAH DENGAN PERKUATAN BRONJONG PADA JALAN TOL ULUJAMI – PONDOK RANJI RAMP BINTARO VIADUCT

Pada Jalan Tol Ulujami – Pondok Ranji STA 03+150 terdapat sebuah jembatan yang opritnya mengalami penurunan yang menyebabkan ketidaknyamanan saat melintas di bahu jalannya. Penyebab penurunan tersebut diduga akibat adanya pergerakan struktur tanah bawah jalan sehingga menimbulkan terjadinya ketidakstabilan bangunan diatasnya. Tujuan studi adalah untuk mengetahui nilai faktor keamanan dinding penahan tanah dengan perkuatan bronjong terhadap kelongsoran, stabilitas geser, guling, dan daya dukung tanah, serta penurunan. Perhitungan tekanan tanah dinding ini menggunakan Teori Rankine. Untuk perhitungan stabilitas terhadap daya dukung tanah menggunakan persamaan Terzaghi. Perhitungan stabilitas dinding terhadap kelongsoran menggunakan metode Fellenius dan perangkat lunak Plaxis 8.6. Penurunan yang dihitung adalah penurunan konsolidasi primer dan sekunder. Hasil perhitungan stabilitas pada dinding penahan gravitasi didapatkan bahwa dimensi dinding tersebut tidak aman terhadap geser dan guling yaitu Fgl = 0,110 ≤ 1,5 dan Fgs = 0,205 ≤ 1,5. Serta penurunan yang terjadi sebesar 57,8 cm selama 62,704 tahun. Dari hasil perhitungan faktor keamanan stabilitas guling dan geser pada dinding penahan gravitasi tersebut, maka direncanakan perbesaran dimensi dinding agar aman terhadap geser dan guling. Didapati faktor keamanannya terhadap geser dan guling menjadi Fgs = 2,225 ≥ 1,5 dan Fgl = 1,740 ≥ 1,5.Kata kunci: dinding penahan tanah, bronjong, stabilitas dinding penahan tanah Bridge at STA 03+150 Ulujami – Pondok Ranji toll road has an approach settlement reduces its service and traffic may disturbed significantly. Settlement probably triggered by soil structure movement at the bottom of the road. The instability occurred and finally structure above damaged. The aim of the study was to calculate the safety factor of retaining wall strengthened with gabion against sliding, shear, overturning, and bearing capacity failure as well as its settlement. The calculation of safety factor against shear and overtuning conducted using Rankine Theory, while bearing capacity calculation done by uses Terzaghi. Calculations of sliding using Fellenius method and Plaxis 8.6 software. The writer also calculate settlement, both at primary and secondary consolidations. The results of stability calculation of gravity wall were as follows: safety factor against overtuning was 0,110 and shear 0,205 respectively, while settlement was 57,8 cm for 62,704 years. After the calculation mention above, in which all of the aspects calculated was not safe, the gravity wall then be redesigned as seen in the figure and the stability increase become 2,225 for shear 1,740 for overturning stability respectively. Using minimum allowable safety factor as 1,5 for all calculations, the gravity wall is now safe.Keywords: retaining walls, gabion, stability of retaining wall