Analisa Perbaikan Sub-Grade Runway Lapangan Terbang dengan Metode Vertical Drain (Studi Kasus Bandara Tempuling di Tembilahan, Propinsi Riau)

Abstract

Soil stabilization for the runway sub-grade in Tampuling Airport, Tembilahan, Riau province is required as the existing soil is in the grouped of peat or soft soil. The compressibility rate of this soil is very height, with the depth of the soft soil of more than 30 meters from its surface. Based on “the worst case scenario” without any soil stabilization treatment, it was estimated that the soil consolidation rate would be 1.7 metre within 20 years period of settlement. In order to speed up consolidation process, the vertical drain method was applied. Design of pre loading technique as well as the calculation of distance between vertical drains is then demonstrated in this paper. It was estimated that the depth of vertical drain would be 18 metres, with the distance between vertical drains is 1.2 metres each; height of pre loading is 4.5 metres. With these design parameters, it was expected that the settlement process would be accelerated by 40 folds (235 months to become 6 months period).

Keywords: Vertical Drain, Pre-Loading, Settlement, Consolidation, Sub-Grade.

ABSTRAK

Perbaikan sub-grade untuk menopang perkerasan lentur runway bandara Tampuling di Tembilahan, Propinsi Riau perlu dilakukan karena sub-grade nya terdiri atas lapisan tanah gambut dan tanah lunak. Tanah ini mempunyai kriteria sebagai tanah dengan tingkat kompresibilitas tinggi mencapai kedalaman 30 m. Berdasarkan skenario terburuk, setelmen konsolidasi tanpa ada perbaikan tanah (sub-grade) akan terjadi sebesar 1,7 meter dalam 20 tahun (235 bulan). Upaya untuk mempercepat konsolidasi dilakukan dengan memasang drainase vertikal (vertical drain). Perencanaan tinggi pre-loading, dan spasi drainase vertikal berikut kedalamannya mempengaruhi proses kecepatan konsolidasi dianalisa. Hasil perencanaan yang diusulkan adalah sebagai berikut; (i) kedalaman drainase vertikal = 18 m;(ii) spasi antar drainase = 1,2 m; dan (iii) tinggi preloading = 4,5 m. Setelmen yang direncanakan dapat dipercepat sebesar 40 kali dari semula 235 bulan menjadi sekitar 6 bulan.

Kata Kunci : Drainase Vertikal, Preloading,  Setelmen, Konsolidasi, Tanah Dasar/Sub-grade

Permalink: http://ejournal.undip.ac.id/index.php/mkts/article/view/3697

[How to cite: Sandhyavitri, A., Wibisono, G., Juniati, S. dan Rioputra, M.D. (2008), Analisa Perbaikan Sub-Grade Runway Lapangan Terbang dengan Metode Vertical Drain (Studi Kasus Bandara Tempuling  di Tembilahan, Propinsi Riau), Jurnal Media Komunikasi Teknik Sipil, Tahun 16, Nomor 3, pp. 231-242]