PROSEDUR PENGUJIAN TANAH UNTUK BEBERAPA DAERAH DI JAWA BARAT
RINGRASAN PROCEDURES FOR TESTING OF WEST JAVA SOILS, Bemby Sunaryo, 1992, Program Magister Sistem dan Teknik Jalan Raya, Program Pasca Sarjana, Institut Teknologi Bandung. Tes klasifikasi (index test) terhadap beberapa tanah residu tropis di Jawa Barat telah dilakukan. Beberapa contoh tanah terganggu (disturbed samples) dari tiga lokasi (Purwakarta, Cikampek dan Bandung) diambil dan dilakukan percobaan laboratorium untuk mengetahui pengaruh pengeringan pada nilai kadar air, batasbatas Atterberg, analisa saringan dan hydrometer serta karakteristik pemadatan. Sebuah contoh tanah tambahan telah diambil dari Lembang untuk mengetahui pengaruh pengeringan pada nilai kadar air dan karakteristik pemadatan. Percobaan laboratorium dilaksanakan dengan menggunakan metoda standar dan modifikasi. Metoda British Standard (1975) dipakai untuk hampir semua percobaan dan dilakukan modifikasi untuk dapat membedakan karakteristik tanah-tanah tropis dengan tanah-tanah di daerah suhu sedang dimana prosedur tes standar telah dipakai sebagai acuan. Dari keseluruhan hasil percobaan laboratorium terbukti bahwa ada perbedaan yang cukup berarti antara hasil percobaan yang diperoleh dengan menggunakan prosedur standar dan modifikasi. Telah dilakukan juga pembandingan dengan hasil-hasil percobaan yang dilakukan pada sekitar tahun 1970. Pengaruh pengeringan pada tanah-tanah residu tropis adalah menurunkan liquid limit, plasticity index, persen lolos pada percobaan hydrometer, menurunkan kadar air optimum dan menaikkan berat jenis kering maksimum pada percobaan pemadatan. Pengujian karakteristik keteknikan melalui tes klasifikasi telah membuktikan bahwa pengaruh pengeringan pada tanah-tanah residu tropis dapat menimbulkan beberapa kesulitan dalam memperkirakan sifat-sifat teknik dari tanah tersebut.
SUMMARY PROCEDURES FOR TESTING OF WEST JAVA SOILS, Bemby Sunaryo, 1992, Program Magister Sistem dan Teknik Jalan Raya, Program Pasca Sarjana, Institut Teknologi Bandung. Index tests for some tropical soils in West Java have been carried out. Disturbed samples were obtained from three location (Purwakarta, Cikampek, and Bandung) and tested to find the effect of drying/wetting on moisture content, Atterberg limits, particle size distribution, and compaction characteristics. An additional sample was taken from Lembang and tested to find the effect of drying on moisture content and compaction characteristics. Laboratory tests were carried out using standard and modified procedures. The British Standard methods were applied to almost all of the laboratory testing, the modifications applied being those which distinguish the characteristics of tropical soils compared with conventional temperate soils for which standard testing procedures have been devised. From the comprehensive laboratory test programme it was found that there were some significant differences between results obtained using standard procedures compared with the modification applied. Comparison was also made with earlier work conducted in the 1970's. The effect of drying on tropical residual soils was found to decrease liquid limits, the plasticity index, and the percentage passing in the hydrometer test. Optimum moisture content in compaction testing was lowered with corresponding increase in maximum dry density. Engineering characteristics were examined using index test results and it was found that the effect of drying on tropical residual soils could make some difficulties in the prediction of likely engineering performance involving these soils.