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"Sebagai negara kepulauan tropis, Indonesia menjadi salah satu negara yang terkena dampak akibat perubahan iklim cukup signifikan. Peningkatan suhu dan intensitas curah hujan yang cukup besar, dapat menyebabkan terjadinya keruntuhan lereng. Secara umum, fenomena keruntuhan lereng pada jenis tanah residual, disebabkan oleh pengaruh dari kenaikan tekanan air pori. Adapun karakteristik utama pada jenis tanah residual ialah sifat heterogenitasnya, dengan pola distribusi ukuran butir yang cukup beragam dan tidak terbatas. Tanah residual sering dijumpai pada daerah tropis, khususnya dalam kondisi tak jenuh, dengan ketinggian muka air tanah yang relatif cukup rendah. Adanya proses infiltrasi pada saat musim penghujan, maka zona tak jenuh membentuk suatu cekungan air tanah, sehingga dapat mengurangi besaran dari hisapan tanah. Sifat hidraulik tanah menjadi faktor penentu dalam memahami setiap perilaku aliran air di bawah tanah, sangat dipengaruhi oleh distribusi ukuran butirnya. Semakin kecil ukuran butir yang terkandung pada suatu jenis tanah, maka semakin tinggi kemampuannya dalam melakukan penyerapan ataupun penyimpanan air di bawah tanah. Akan tetapi, sangat berbanding terbalik terhadap kemampuan pengaliran air di bawah tanah yang cukup rendah. Oleh karena itu, penelitian ini dilakukan dengan tujuan untuk mengetahui karakteristik dari sifat hidraulik tanah residual dan sampel RCA, akibat pengaruh distribusi ukuran butir yang berbeda. Pada penelitian ini, pengukuran hisapan tanah dilakukan secara aktual dengan menggunakan alat HSPS dan Tempe Cell, secara akhir akan menghasilkan kurva karakteristik air-tanah. Adapun kurva karakteristik air-tanah beserta hasil pengujian permeabilitas jenuh, digunakan pada estimasi terhadap fungsi permeabilitas tanah, sehingga sifat hidraulik tanah dapat diketahui secara pasti dan juga spesifik.

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As a tropical island country, Indonesia is one of the countries significantly affected by climate change. A large increase in temperature and rainfall intensity can cause slope collapse. In general, the phenomenon of slope failure in residual soil types is caused by the influence of increasing pore water pressure. The main characteristic of residual soil types is their heterogeneity, with diverse and unlimited grain size distribution patterns. Residual soil is often found in tropical areas, especially in unsaturated conditions, with relatively low groundwater levels. With the infiltration process during the rainy season, the unsaturated zone forms a perched water table, thereby reducing the amount of soil suction. Soil hydraulic properties are a determining factor in understanding the behavior of groundwater flow, which is strongly influenced by the grain size distribution. The smaller the grain size of a type of soil, the higher its ability to absorb or store groundwater. However, this is inversely proportional to the low ability of groundwater to flow. Therefore, this research was carried out with the aim of determining the characteristics of the hydraulic properties of residual soil and RCA samples, due to the influence of different grain size distributions. In this research, actual measurements of soil suction were carried out using HSPS and Tempe Cell, ultimately producing a soil – water characteristic curve. The soil – water characteristic curve and the results of the saturated permeability test are used to estimate the soil permeability function, so that the hydraulic properties of the soil can be known predictably and specifically."

"Interaksi tanah struktur telah diteliti selama lebih dari 40 tahun, tetapi masih banyak kontroversi dalam pengunaannya. SNI Gempa yang baru SNI-1726-2012 telah mengakomodir analisa interaksi tanah-struktur dengan memperhitungkan interaksi tanah-struktur gaya geser gempa boleh dikurangi sampai 30 . Studi ini meneliti pengaruh interaksi tanah-struktur pada bangunan dengan tinggi 8, 12, 16, 20 lantai dengan dua lapis basement untuk dilihat besarnya reduksi gaya geser dasar dan pengaruhnya pemodelan interaksi tanah-struktur pada ductility demand dari struktur.Hasil studi menunjukan bahwa pengurangan gaya geser efektif untuk bangunan rendah 8 lantai dengan pengurangan sekitar 10 dan berkurang seiring dengan bertambahnya ketinggian atau periode struktur, sedangkan untuk ductility demand cenderung berkurang dengan berkurangannya kekakuan tanah Vs lebih kecil.

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Soil structure interaction has been investigated more than 40 years, but there is still many controversy regarding the role of SSI in the seismic performance of structure founded in soft soil. Indonesian seismic design code SNI 1726 2012 has been accommodate soil structure interaction to account SSI effect, seismic base shear can be reduction to 30 .This study investivigate influence of soil ndash structure interaction on buildings with 8, 12, 16, 20 storey height with two layers basement. This study show building with short storey 8 storey building with reduction about 10 , the reduction decrease with increase the height of building or periode of fix structure. Meanwhile the ductility demand decrease with decrease the stiffness soil Smaller Vs "

"Kecamatan Mancak adalah kecamatan yang paling sering terjadi tanah longsor di Kabupaten Serang. Dengan tanah longsor bisa diprediksi melalui kelembapan tanah dan biasanya tanah longsor sering terjadi di tanah yang lembap, maka ada kemungkinan bahwa hal tersebut benar. Penelitian ini menggali persebaran spasial kelembapan tanah dengan tanah longsor di Kecamatan Mancak serta menguji keterkaitan antara kelembapan tanah dengan tanah longsor. Untuk mengeksplorasi persebaran spasial kelembapan tanah dan tanah longsor tersebut, sistem informasi geografis dapat digunakan untuk meng-overlay peta kelembapan tanah dengan peta tanah longsor dan menggunakan metode korelasi Pearson untuk mengeksplorasi korelasi antara kelembapan tanah dengan tanah longsor. Hasil dari overlay dan uji statistika adalah adanya hubungan berbanding terbalik antara kelembapan tanah dengan tanah longsor.

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Mancak Subdistrict has the most landslides among all other subdistricts in Serang Regency. As landslides are predicted via knowing the soil moisture and landslides likely to occur at moist soils, there are chances that that is actually correct. This research studies spatial distributions of soil moisture and spatial distribution of landslides in the subdistrict and also studies the linkage between soil moisture and landslides. The research uses geographical information system to overlay the maps of soil moisture and landslides and find correlations between both using Pearson’s correlation. The result is the reverse as landslides tends to occur at lower soil moisture."

"This book explains the hypoplastic modelling framework. It is divided into two parts, the first of which is devoted to principles of hypoplasticity. First, the basic features of soils mechanical behaviour are introduced, namely non-linearity and asymptotic properties. These features are then incorporated into simple one-dimensional hypoplastic equations for compression and shear. Subsequently, a hypoplastic equivalent of the Modified Cam-Clay model is developed in 2D space using stress and strain invariants to demonstrate key similarities and differences between elasto-plastic and hypoplastic formulations. Lastly, the mathematical structure of hypoplastic models is explained by tracing their historical development, from the early trial-and-error models to more recent approaches. In turn, Part II introduces specific hypoplastic models for soils. First, two reference models for sand and clay are defined. After summarising their mathematical formulations, calibration procedures are described and discussed. Subsequently, more advanced modelling approaches are covered: the intergranular strain concept incorporating the effects of small strain stiffness and cyclic loading, viscohypoplasticity for predicting rate effects, soil structure to represent structured and bonded materials and soil anisotropy. The book concludes with a description of partial saturation and thermal effects: topics that are increasingly important to the disciplines of energy and environmental geotechnics.Selecting a constitutive model and its parameters is often the most important and yet challenging part of any numerical analysis in geotechnical engineering. Hypoplasticity involves a specific class of soil constitutive models, which are described in detail here. The book offers an essential resource, both for model users who need a more advanced model for their geotechnical calculations and are mainly interested in parameter calibration procedures, and for model developers who are seeking a comprehensive understanding of the mathematical structure of hypoplasticity."