Pelatihan Pengujian In-Situ Tanah bagi laboran Muda Mekanika Tanah

In-situ test adalah salah satu metode pengujian geomekanika yang pelaksanaannya dilakukan langsung di lapangan, tanpa pengambilan percontoh untuk laboratorium. Rendahnya minat laboran dalam mendalami bidang mekanika tanah khususnya pengujian tanah baik di lapangan maupun di laboratorium. Hal ini di sebabkan oleh para laboran menganggab bahwa pengembangan keahlian dalam menggunakan peralatan pengujian dan pengolahan data mekanika tanah cukup sulit dan mahal. HIMATESI merupakan sebuah himpunan mahasiswa yang beranggotakan para peneliti muda, laboran muda atau mahasiswa tingkat akhir yang sedang melakukan penelitian dan pengujian mekanika tanah. Mitra menyadari perlu peningkatan pemahaman tentang pengujian In-Situ tanah. Namun disisi lain menjadi ketakutan tersendiri bagi mitra tentang penyelsaiaan permasalahan yang timbul dalam pengujian In-Situ tanah pada saat pelaksanaan dilapangan. Perguruan tinggi menjawab persoalan mitra dengan memberikan pengetahuan tentang pengujian In-Situ tanah dan pelatihan penggunaan peralatan pengujian In-Situ tanah serta trik-trik menhadapi permasalahan dalam pengujian In-Situ tanah pengujian In-Situ tanah secara gratis. Kegiatan Pengabdian masyarakat dalam bentuk pelatihan pengujian In-Situ Tanah bagi laboran mekanika tanah yang diadakan bertujuan untuk memberikan bekal informasi tentang tentang pengenalan dan penggunaan alat pengujian In-Situ seperti Dynamic Cone Penetrometer, alat Handbore dan alat Sandcone. Hasil pelatihan ini mampu meningkatkan pengetahuan peserta terhadap penggunaan alat pengujian In-situ tanah dan trik-trik dalam mengatasi permasalahan dilapangan terhadap penggunaan alat Insitu sehingga diharapkan para peserta dapat mengimplementasikan ilmu yang di dapat dalam pelaksanaan dilapangan nantinya.

Evaluation of soil replacement and cement grout injection in soil settlement

This paper discusses the process of original soil stabilization in Trans Sumatra Bakauheni-Terbanggi Besar Toll Road Project Package 2 Sidomulyo-Kotabaru. The soil replacement process was conducted at approximately 24 kilometres along the toll’s main road. The original soil bearing capacity analysis stage was by performing a Dynamic Cone Penetrometer (DCP) and Sondir test to analyze the deep of hard soil. A soil replacement was carried out to replace the original soil with soil that has appropriate specification. the piling up process was conducted in stages, which has Sandstone in such of the layer. The research done about the landfill sample was retaken and collected at 68 points. The stockpile soil samples collection was then followed by the analysis which was conducted in the laboratory to find the soil bearing capacity. There are 4 types of bearing capacity parameters analyzed, namely specific gravity, water content, aggregate analysis (Sieve Analysis), and consistency limit (Atterberg Limit). Referring to it, then there was the classification of soil types according to AASHTO M145 & Casagrande Soil Classification System. A point that has settlement after soil replacement is STA 52+000. So, there need to add soil stabilization, that is cement grout injection. Researchers analyzed the soil settlement by interpretation method. Results showed that soil replacement and cement grout injection could decrease a soil settlement by about 15.07 cm to become 0.93 cm.

Evaluasi Variabilitas Kinerja Struktur Perkerasan Jalan Berbasis Pengujian Seismik

Evaluasi perkerasan jalan diperlukan untuk memeriksa kerusakan awal yang terjadi pada perkerasan. Penilaian perkerasan dilakukan untuk memprediksi kualitas material perkerasan secara fungsional dan struktural. Penelitian ini bertujuan untuk menilai dan mengevaluasi perkerasan jalan secara struktural menggunakan pengukuran seismik Spectral Analysis of Surface Waves (SASW). Metode SASW menguji sifat material perkerasan sebagai teknik evaluasi struktural. Metode SASW merupakan metode seismik non-destruktif yang menghasilkan, mengukur, dan memproses gelombang Rayleigh yang terdispersi. Selanjutnya, proses inversi dengan teknik optimasi digunakan untuk menganalisis data dispersi gelombang Rayleigh guna menghasilkan profil kekakuan setempat, dalam parameter kecepatan gelombang geser dan modulus elastisitas. Parameter kekakuan dari metode ini yang dihasilkan pada tingkat regangan mikroskopis yaitu kurang dari 0,001%, di mana pada tingkat ini, bahan tanah berperilaku elastis linier. Hasil dari uji SASW selanjutnya dibandingkan dengan uji Marshall dan nilai uji Dynamic Cone Penetrometer (DCP). Pengamatan visual juga dilakukan untuk menentukan penilaian fungsional untuk mengukur seberapa besar kerusakan permukaan jalan. Hasil penelitian menunjukkan bahwa metode SASW dapat secara efektif mengukur kecepatan gelombang geser dan variabilitas modulus elastisitas pada setiap lapisan perkerasan. Studi ini merekomendasikan pengujian seismik untuk memeriksa variabilitas kinerja struktural perkerasan jalan terpasang.

Comparison of California Bearing Ratio (CBR) Value Based on Cone Penetration Test (CPT) and Dynamic Cone Penetrometer (DCP)

In civil engineering, land is important because as a place for building infrastructure to be built, so that the building infrastructure on it is stable, adequate carrying capacity is needed. The amount of soil bearing capacity can be determined in several ways, including the California Bearing Ratio (CBR) Field Test, Cone Penetration Test (CPT) and Dynamic Cone Penetrometer (DCP). The CBR and DCP tests are often used to determine the level of surface soil density on road structures, while CPT is usually used to determine the hard soil layer on the building structure. However, in certain situations Sondir and DCP data are often used to predict the CBR value, because the test is quite practical and efficient compared to the CBR test. CBR testing requires heavy equipment which in most small-scale projects is not available. In this study, we compared the CBR value based on the data obtained from the Sondir and DCP tests. Data collection was carried out in Surakarta and its surroundings. Based on the test results, the CBR value generated from the DCP test tends to be smaller than that from the CPT test with a ratio of 0.62: 1. This study resulted in the relationship between CBR values from the results of the CPT and DCP tests shown in the following equation: CBR (DCP) % = 0.2552 CBR(CPT) + 2.6306 and CBR (DCP) % = 0.617 CBR(CPT).

Organosilane and Lignosulfonate Stabilization of Roads Unbound: Performance during a Two-Year Time Span

The construction of the new Norwegian E39 highway comprises the excavation of extended tunnelling systems, which lead to a tremendous amount of blasted rocks. Among others, a sustainable cost-benefit application of these resources is represented by their local use as construction material in the unbound layers of the roads. Two types of nontraditional additives are investigated to improve the mechanical properties of aggregates; this is particularly useful for those rocks that do not fulfil the design requirements in their natural status. This work focuses on the field application of two innovative stabilizing technologies based on organosilane and lignosulfonate. The performance of these additive agents is characterized by considering three typical road base layer sections built on purpose according to real practice and added with water (no treatment), organosilane, and lignosulfonate. The test sections are subjected to climatic actions only as neither traffic nor surface courses are applied. With the investigation covering two years, the layers’ stiffness, deformation, and resistance to penetration are evaluated by employing a light-weight deflectometer and dynamic cone penetrometer. Both organosilane and lignosulfonate significantly enhance the mechanical properties of the treated base layers.