Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Dengan semakin terbatasnya lahan untuk pembangunan fasilitas yang diperlukan manusia mengakibatkan tidak dapat dihindarinya pembangunan diatas tanah lempung lunak. Secara umum tanah lempung lunak adalah suatu jenis tanah kohesif yang mempunyai sifat yang sangat kurang menguntungkan dalam konstruksi teknik sipil yaitu kuat geser rendah dan kompresibilitasnya yang besar. Kuat geser yang rendah mengakibatkan terbatasnya beban (beban sementara ataupun beban tetap) yang dapat bekerja diatasnya sedangkan kompresibilitas yang besar mengakibatkan terjadinya penurunan setelah pembangunan selesai. Oleh karena itu terbatasnya lahan dan tidak dapat dihindarinya pembangunan diatas tanah lunak maka perlu diadakannya perbaikan pada tanah lunak. Banyak cara yang dilakukan untuk perbaikan tanah lunak agar dapat meningkatkan kekuatan geser dan memperkecil kompresibilitasnya. Salah satu caranya adalah dengan metode Preloading , seperti yang digunakan dalam panelitian ini pada tanah lempung lunak Meruya, Jakarta Barat. Preloading adalah pemberian beban awal terlebih dahulu sebelum pelaksanaan beban konstruksi agar tanah tersebut terkonsolidasi dahulu sehingga tanah telah termampatkan, setelah itu disingkirkan sewaktu konstruksi mulai dilaksanakan sehingga dengan prapembebanan ini dapat memperkecil penurunan sisa (residual settlement), mempercepat waktu penurunan dan dapat meningkatkan kekualan gesemya. Preloading yang dilaksanakan di dalam laboratorium terhadap tanah lempung lunak ini adalah dengan menggunakan alat uji Triaksial dengan kondisi Terkonsolidasi Terdrainasi yang dilakukan dengan cara memberikan beban konsolidasi sebesar 1,5 kali Pe (prakonsolidasi) kemudian setelah itu beban konsolidasi dilepas selama 1 hari dan dilanjutkan dengan melakukan kompresi sampai tanah mengalami keruntuhan. Hasil pengujian ini dianalisa dengan menggunakan Mohr Coulomb dan Stress Path lalu dibandingkan dengan data tes UU (kondisi sebelum preloading) sehingga dapat diketahui pengaruh preloading terhadap peningkatan kekuatan geser tanah.

Abstrak :
ABSTRAK
The purpose of this research is to study and compare the stabilities of soft clay embankments for flooding protection using soil compaction and soil lining techniques in construction. There are five types of soft clay embankments with three-meter height used in this research. The width at the top of the embankment is one meter and the vertical to horizontal ratio of slope of embankment on the water side equals 1:1. The soil compaction technique was used to construct the embankment types 1, 2 and 3 and the value of coefficient of permeability of clay in embankment to be 1x10-5 cm./sec was given. The vertical to horizontal ratio of slope of embankments on the dry side equal 1:1, 1:1.5 and 1:2, respectively. The soil lining was used to construct the embankment types 4 and 5 and the vertical to horizontal ratio of slope of embankments on the dry side equals 1:1, without compaction techniques. Lining material with 0.10 meter thickness was placed on the water side surface of the embankment. The coefficient of permeability of lining material used in embankment types 4 and 5 equals 1x10-5 cm/sec. and 1x10-6 cm./sec., respectively. The research process consisted of using parameters obtained from shear strength test and water flow test through soft clay embankment simulated in laboratory to analyze water flow and slope stability analysis of the embankment. In addition, the area and budget for construction of embankment, not including the soil compaction and soil lining cost, were used to select the suitable type of soft clay embankment. The results showed that the soft clay embankment type 5, using soil lining on the water side surface of the embankment, was the most suitable embankment. Also, the level of stability of the soft clay embankment type 5 had the highest value with the need to use area and budget for construction less than embankment types 1, 2 and 3.

Abstrak :
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.

---

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.

Abstrak :
The pavement of the nailed-slab system has been proposed as an alternative solution for addressing the rigid pavement problem in soft soils. This system is used for developing a rigid pavement. The simple method of using an equivalent modulus of subgrade reaction (k?) in nailed-slab system analysis was proposed by a previous researcher. This modulus consists of the modulus of subgrade reaction from a plate load test (k) and an additional modulus of subgrade reaction due to pile installing (Dk). The additional modulus of subgrade reaction has been proposed by some authors. The displacement factor was used in determining the additional modulus of subgrade reaction. This factor is difficult to define. In this research, the prototype test of a nailed slab with single-pile installation was conducted to learn the validation of the theory of the additional modulus of subgrade reaction on a full-scale dimension. The prototype was constructed on soft clay, and the connection between the pile and slab was perfect monolithically. This system was loaded by centric load. A new curve of the displacement factor is proposed. Calculated deflections based on this curve were compared to the observed deflection and resulted in good agreement with the observation. Hence, it can be used in preliminary design.

Abstrak :
The pavement of the nailed-slab system has been proposed as an alternative solution for addressing the rigid pavement problem in soft soils. This system is used for developing a rigid pavement. The simple method of using an equivalent modulus of subgrade reaction (k’) in nailed-slab system analysis was proposed by a previous researcher. This modulus consists of the modulus of subgrade reaction from a plate load test (k) and an additional modulus of subgrade reaction due to pile installing (k). The additional modulus of subgrade reaction has been proposed by some authors. The displacement factor was used in determining the additional modulus of subgrade reaction. This factor is difficult to define. In this research, the prototype test of a nailed slab with single-pile installation was conducted to learn the validation of the theory of the additional modulus of subgrade reaction on a full-scale dimension. The prototype was constructed on soft clay, and the connection between the pile and slab was perfect monolithically. This system was loaded by centric load. A new curve of the displacement factor is proposed. Calculated deflections based on this curve were compared to the observed deflection and resulted in good agreement with the observation. Hence, it can be used in preliminary design.