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"Cement column reinforcement is a method of soil reinforcement used in the field to increase soil's shear strength and decrease soil's compressibility. A set of laboratory studies of the effect of cement column reinforcement on shear strength in an undrained condition was conducted on kaolinite clay by using a triaxial apparatus to simulate real conditions. For triaxial testing, the soil samples were made using an extruder. Afterward, to make the composite samples, the soil sample cores were bored to create holes 5 mm in diameter and 50 mm long, and the holes were filled with cement slurry. The soil samples' cement column reinforcements were cured for seven, 14, and 21 days. Then, the soil and composite samples were saturated, consolidated, and applied to the loading. In this test, applying shear force to the soil sample and composite samples was carried out until the maximum stress and a strain of 12% were reached. The results from this test indicated that the cohesion parameter and angle of the internal friction of composite samples are higher and lower, respectively, than the unreinforced soil samples in theconsolidated, undrained triaxial test. It was found that a cement column reinforcement system can improve soil shear strength."

"Mudflow is a type of mass movement with high velocity. It is comprised mainly of silt and clay-sized particles. Mudflow movement behavior involves undrained shear strength and viscosity as part of a resistance force that withstands shear stress as a driving force. Many methods have been developed to determine the value of viscosity. This study used Vallejo and Scovazzo’s modification method to determine the viscosity value, and assumed that mudflow material behaves as a Bingham plastic material. A flume channel was used in this study to measure the displacement and time required for mud to flow in order to obtain the mudflow transportation velocity. The measurement was conducted for four different slope angles and water contents. To compare the samples, Kaolin soil was used for the pilot project and Parakan Muncang soil was used as the natural landslide material in order to obtain the viscosity value throughout this study. This study aims to evaluate the capability of Vallejo and Scovazzo’s method to determine the viscosity value. We found that Vallejo and Scovazzo’s method cannot be used in a single slope angle. This approach requires that the sliding plane angle be adjusted for varying shear stress magnitudes, and that, consequently, different strain rates for each shear stress are obtained. The correlation curve between the shear stress and the strain rate, which corresponds to the Bingham plastic material curve, needs to be governed. The viscosity value was obtained by calculating the gradient of the linear tangent line. Furthermore, Vallejo and Scovazzo’s method is recommended only for tests at a low strain rate level, as a high strain level would cause difficulties in recording string displacement and mud transportation time. However, testing mud at a low strain rate level will obtain a higher value of mud viscosity that is not representative of mudflow viscosity."

"Beton merupakan material getas dan lemah terhadap tarik dibandingkan baja. Salah satu solusi untuk mengatasi kelemahan beton adalah penambahan serat plastic jenis polypropylene dalam bentuk kemasan air minum pada material beton. Berangkat dari keberhasilan fiber reinforced concrete, maka dilakukan penelitian mengenai pengaruh penambahan cacahan limbah gelas plastik PP dalam meningkatkan kinerja beton. Tujuan penelitian ini adalah untuk mempelajari efektifitas penggunaan cacahan limbah plastik PP terhadap peningkatan kuat tekan dan kuat geser beton dengan fc? = 25 MPa, di samping itu untuk mengurangi penumpukan limbah gelas plastik minuman yang terus meningkat setiap tahun.Kadar cacahan polypropylene yang ditambahkan pada beton normal adalah 0,00 kg/m3 (0,00 %); 0,90 kg/m3 (0,10 %); 1,80 kg/m3 (0,20 %); 2,70 kg/m3 (0,30 %); 4,50 kg/m3 (0,50 %); 6,30 kg/m3 (0,70 %); 9,0 kg/m3 (1,00 %); 18,0 kg/m3 (2,00 %); 27,0 kg/m3 (3,00 %) untuk pengujian kuat tekan dengan umur benda uji 7 hari dan 28 hari, serta 0,00 kg/m3 (0,00 %); 0,90 kg/m3 (0,10 %); 1,80 kg/m3 (0,20 %); 2,70 kg/m3 (0,30 %); 4,50 kg/m3 (0,50 %); 6,30 kg/m3 (0,70 %); 9,0 kg/m3 (1,00 %) untuk pengujian kuat geser dengan umur benda uji 28 hari.Percobaan pembebanan yang dilakukan meliputi pembebanan untuk uji tekan beton, uji geser beton dan uji modulus elastisitas beton. Benda uji percobaan uji tekan dan uji modulus elastisitas beton adalah silinder dengan diameter 15 cm dan tinggi 30 cm. Benda uji percobaan uji geser beton adalah balok double ? L dengan ukuran ( 5 , 7 30 20 × × ) cm⊃³;.Penelitian dilaksanakan di Laboratorium Struktur dan Material Departemen Sipil Fakultas Teknik, Universitas Indonesia. Metode yang digunakan dalam penelitian ini adalah metode eksperimental. Hasil pengujian akan dibahas dengan analisa kuantitatif, analisa kualitatif dan analisa biaya. Metode pengujian untuk material dasar dan beton mengacu pada ASTM Standard, sedangkan untuk metode rancang campur beton berdasarkan U.S. Bureau of Reclamation.Dari hasil penelitian beton, dapat disimpulkan dengan bertambahnya kadar cacahan, cenderung adanya penurunan slump pada penambahan kadar cacahan lebih besar dari 0,30%. Dari hasil pengujian, pada penambahan kadar cacahan polypropylene 1,00% terjadi peningkatan kuat tekan 7 hari sebesar 5,000%. Sedangkan tidak ada peningkatan kuat tekan yang signifikan pada kuat tekan 28 hari. Pada penambahan kadar 0,50% peningkatan kuat geser 28 hari sebesar 42,647%.

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Concrete as construction material is known brittle material and has weak tensile strength, compared to steel material. Therefore, need an alternative solution to improve characteristics of the concrete. One of the alternative solution is by adding fiber polypropylene plastic waste on normal concrete.Based on the successful of fiber reinforced concrete, this research is done by adding crushed polypropylene plastic waste to improve characteristics of the concrete material. The object of this research is to learn the effect of usage polypropylene plastic waste in compressive and shear strength with fc? = 25 MPa, besides to decrease urban waste problem.The proportion of crushed polypropylene added to normal concrete are 0,00 kg/m3 (0,00 %); 0,90 kg/m3 (0,10 %); 1,80 kg/m3 (0,20 %); 2,70 kg/m3 (0,30 %); 4,50 kg/m3 (0,50 %); 6,30 kg/m3 (0,70 %); 9,0 kg/m3 (1,00 %); 18,0 kg/m3 (2,00 %); 27,0 kg/m3 (3,00 %) for compressive strength test on 7 days and 28 days, also 0,00 kg/m3 (0,00 %); 0,90 kg/m3 (0,10 %); 1,80 kg/m3 (0,20 %); 2,70 kg/m3 (0,30 %); 4,50 kg/m3 (0,50 %); 6,30 kg/m3 (0,70 %); 9,0 kg/m3 (1,00 %) for shear strength test on 28 days.The tests consist of compressive test, shear test and modulus of elasticity test. The specimen for compressive and modulus of elasticity test is cylinder with 15 cm diameter and 30 cm height. The specimen for shear test is double ? L beam with sizing ( 5 , 7 30 20 × × ) cm³.The research is done at Structure and Material Laboratory Civil Engineering Department, University of Indonesia. This research used experimental method. The result of experiment will analyze by quantitative analysis, qualitative analysis and cost analysis. Standard test method for raw material and concrete is based on ASTM Standard. Mix design method is based on U.S. Bureau of Reclamation. The result for slump test remain stable by adding crushed polypropylene plastic waste until 0,30%. After proportion of crushed polypropylene is higher than 0,30% added on normal concrete, slump value will decrease.From the compressive test on 7 days, there is 5,00% of compressive strength improvement by adding 1,00% of crushed polypropylene plastic waste on normal concrete. From the compressive test on 28 days, there is no significant result of compressive strength improvement. From the shear test on 28 days, there is 42,65% of shear strength improvement by adding 0,50% of crushed polypropylene plastic waste on normal concrete"

"Kuat geser tanah gambut merupakan salah satu faktor yang perlu diperhatikan dalam perancangan pondasi atau subgrade pembangunan jalan khususnya di daerah yang banyak mengandung tanah gambut. Metode yang digunakan adalah pengambilan sampel tanah gambut Desa Tampan Riau yang dipadatkan dengan 3 (tiga) kondisi persiapan sampel yaitu kondisi undisturbed, pembasahan, dan pembasahan pengeringan sebelum pengujian triaksial consolidated undrained. Efek dari pemadatan, pembasahan, dan pengeringan diamati dari grafik hubungan tegangan deviator-tegangan efektif; perubahan tekanan air pori-regangan; dan tegangan deviator-regangan kemudian hasilnya dibandingkan pada tiap-tiap kondisi dan kadar air pemadatan.

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The shear strength is one of factor that important to know in foundation engineering or road construction subgrade especially in organic soil area. This method of research used gambut soil from Tampan Village in Riau that compacted and there are 3 (three) conditions preparation of it, there are undisturbed sample, wetting process, and wetting drying process before triaxial consolidated undrained test. The effect of compaction, wetting, and drying will be shown in the graphics relation between deviatory stress-effective stress; pore water stress-strain; and deviatory stress-strain, finally the data results for each different conditions and water contents compaction will be compared."

"Pengujian kuat geser tanah merupakan masalah yang berhubungan dengan stabilitas massa tanah. Menentukan kuat geser tanah kaolin (mineral tanah lempung) di laboratorium, terlebih dahulu dilakukan pengujian untuk menentukan Indek Properties tanah sebelum dilakukan pengujian kuat geser terhadap sample tanah. Alat yang digunakan pada pengujian ini adalah alat uji geser sudu laboratorium (vane shear test laboratory).Pengujian kuat geser digunakan untuk analisa daya dukung tanah dan stabilitas lereng dengan tujuan pengujian, untuk menentukan nilai parameter-parameter kekuatan geser dari hasil uji geser sudu (vane shear test) laboratorium dan membandingkan hasil pengujian kuat geser tanah lempung antara metode pengujian kuat geser sudu (vane shear test) dengan metode pengujian triaksial.

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Measuring of shear strength of soils to constitute problem that is engaged soiled mass stability. Determining shear strength of kaolin (clays soiled mineral) at laboratory, earlier been done tests to determine Indek Properties of kaolin before done by measuring of shear strength to soiled sample. Tool that is utilized on this test is vane shear laboratory.

Measuring of shear strength of soils to be utilized to analyse soiled advocate energy, to determine parameter of shear strength with measuring vane shear laboratory and compares the measurements of shear strength of clay among vane shear test laboratory with triaksial UU tests."

"Permasalahan yang timbul akibat pembebanan pada lapisan tanah lunak adalah kompresibilitas yang tinggi dan kekuatan geser rendah. Untuk mengatasinya dapat dilakukan perbaikan tanah antara lain metode preloading. Preloading adalah pemberian beban awal pada lapisan tanah sebelum beban konstruksi bekerja di atasnya. Besar preloading yang diberikan pada percobaan ini adalah pc + ?p, dengan ?p sebesar 50 kPa. Untuk mengetahui nilai kompresibilitas akibat preloading dilakukan dengan uji konsolidasi menggunakan alat oedometer. Adapun prosesnya adalah mula-mula tanah diuji dibebani secara bertahap hingga mencapai beban preloading. Setelah tanah terkompresi, beban preloading kemudian dikurangi sampai nol. Kemudian tanah diuji, dibebani kembali seperti proses konsolidasi biasa sampai beban maksimum. Sedangkan untuk mengetahui kekuatan gesernya dilakukan dengan uji triaksial terkonsolidasi terdrainasi, besarnya beban preloading pada uji triaksial terkondolidasi terdrainasi prinsipnya sama dengan uji tanpa preloading, perbedaannya hanya pada tahap konsolidasi, dimana tegangan sel yang diberikan pada tahap ini sebesar beban preloading, dan setelah dikonsolidasi tegangan sel diturunkan sesuai keadaan awalnya dan didiamkan selama 24 jam sebelum dikompresi. Hasil dari uji yang dilakukan menunjukkan bahwa kompresibilitas tanah setelah di preloading akan menjadi lebih kecil. Penurunan nilai kompresibilitas tanah untuk beban lebih kecil dari beban preloading menunjukkan bahwa nilai Cc yang berubah menjadi Cr. Sehingga penurunan konsolidasi setelah pemberian beban preloading akan jauh lebih kecil. Berdasarkan hasil uji triaksial konsolidasi terdrainasi, pengaruh preloading menunjukkan adanya peningkatan parameter kekuatan geser tanah yaitu pada nilai kohesi dan sudut geser terdrainasi (cd dan _d)

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High compressibily and low shear strength are two problems that caused by giving load to I soft soil clay. One of the soil improvement methods to solve those problems is preloading method. Preloading means giving early load to soil layer before construction load work. Preloading load gives on this experiment is pc + ?p, with ?p given 50 kPa. consolidation test using oedometer is done to find compressibility value caused by preloading. First process I begin by giving gradually load until it reach preloading load. Then preloading load is being ' reduced to zero value. After that sample being loaded again the same as common consolidation process till maximum load. To find the shear strength of preloading is done by consolidation drained triaxial test, with same preloading load given in consolidation test. Actually, preloading ! test on consolidation drained test have the same princip like without preloading, with the difference on consolidated step, where the given cell pressure on this stage equal to preloading load, and after being consolidated, cell pressure is being reduced till its early condition, then keep it still for 24 hours before being compressed. Final result value from the test shows that soil compressibility after preloading would ; become much smaller. Degradation value soil compressibility for smaller load than preloading i load shows that Cc value turns to Cr value. According to triaxial consolidation drained test, the preloading caused the value of strength shear parameters increase, that parameter are cohesion and shear strength shear (cd and _d)."

"Indonesia mempunyai iklim dan kondisi tanah yang dapat dikatakan mendukung adanya wilayah yang digolongkan mempunyai tanah sulit. Tanah sulit disini diartikan sebagai tanah sangat lunak organik atau gambut dan tanah lunak yang berpotensi mengembang tinggi ( tanah ekspansif ). Makin mendesaknya kebutuhan akan lahan untuk permukiman di kota, mahalnya lahan dengan tanah stabil, dan berkembangnya wilayah permukiman di daerah terutama wilayah transmigran, membuat pemanfaatan wilayah ini tidak dapat dihindarkan.Permasalahan yang timbul akibat pembebanan pada lapisan tanah lunak adalah kompresibilitas yang tinggi dan kekuatan geser yang rendah. Untuk mengetahui kekuatan geser dari tanah lempung lunak tersebut maka perlu dilakukan beberapa pengujian, dalam karya tulis ini uji yang dilakukan adalah uji geser sudu (Vane Shear Test) yang dilakukan di lapangan dan uji triaksial dengan dalam kondisi Unconsolidated Undrained yang dilakukan di laboratorium. Uji geser sudu (Vane Shear Test) dimaksudkan untuk menentukan kekuatan lempung jenuh sempurna dalam keadaan tidak terdrainasi, sedangkan uji triaksial dilakukan dengan tujuan untuk mengetahui sudut geser tanah dan nilai kohesi suatu tanah.

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Indonesia has ground condition and climate which can be told to support region existence that is classified has difficult ground. Difficult ground is interpreted as very organic soft clay or peat and soft clay which have the high potency to expand (expansive clay). More and more insist on the farm requiremenl for settlement in town, its costly land with stable ground, and settlement regional expansion in area especially the transmigrant region, making this regional explosion cannot be obviated.

Problem which is arising out because of the effect of encumbering at] soft clay are high compressibility and low shear strength. To know shear strength from the soft clay, it requires to be conducted by some examination, in this final assignment the test which was taken were Vane Shear Test that was conducted in field and Triaxial Test under Unconsolidated Undrained condition that was conducted in the laboratorium. Vane Shear Test was intended to determine unsaturated clay strength in undrained condition, while triaxial test was conducted as a mean to know sheat angle and cohesion of the clay."

"Penggunaan cerucuk merupakan salah satu metode perbaikan tanah yang banyak diaplikasikan terutama pada lapisan tanah lunak untuk membantu meningkatkan kekuatan geser serta mengurangi penurunan tanah yang terjadi. Untuk mengetahui pengaruh dari penggunaan cerucuk terhadap kekuatan geser tanah, dilakukan pengujian dalam skala laboratorium pada tanah kaolin dengan uji triaksial terkonsolidasi takterdrainasi. Untuk pemodelan tanah lunaknya, digunakan slurry kaolin yang di-preloading dengan tekanan 100 kPa. Sedangkan untuk cerucuknya, dimodelkan dengan batang kayu berdiameter 2 mm dan variasi panjang 25 mm dan 50 mm. Hasil pengujian menunjukkan bahwa penggunaan cerucuk di satu sisi meningkatkan kohesi tanah, namun di sisi lain menurunkan sudut gesernya. Peningkatan kohesi tersebut sebanding dengan panjang dan jumlah cerucuk yang digunakan. Demikian pula dengan penurunan sudut gesernya.

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Installation of the timber pile is one of reinforcement method applied mainly in the soft soil layer to help improve the shear strength and reduce the settlement. The laboratorium test was performed to investigate the effect of timber pile installation to shear strength of kaolin clay under consolidated undrained triaxial test. Kaolinite clay using to modelled soft soil layer. For modeling soft soil, kaolin slurry used in-preloading with 100 kPa pressure. As for timber pile modelled with the wooden stick with 2 mm of diameter and 25 mm of length for the first variation and 50 mm of length for the second variation. The test result show that timber pile reinforcement contribute to increase the cohesion parameter but in the other hand it decrease the friction angle. Increased cohesion is comparable to the length and number of timber pile used. Similarly, the decrease in friction angle."

"Study of loading rate effect on behavior of clay under one-way undrained cyclic loading was conducted by using triaxial automated system apparatus under stress controlled and undrained condition. The rests were carried out on Depok clay samples which compacted rising Standard Proctor at loading rate of 0, 05 and 0,5 %/min. and with a confining pressure (o3) of 50 kPa on sample. The samples were saturated until the coefficient B higher than 0.97. The test results indicated that the larger of delta-strain occured or higher loading rate."