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Journal : U Karst

Development Study of T-Z Curve Generated from Kentledge System and Bidirectional Test Nisa Utami Rachmayanti; Paulus Pramono Rahardjo
U Karst Vol 5, No 1 (2021): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3869.756 KB) | DOI: 10.30737/ukarst.v5i1.1090

Abstract

Pile loading tests to check the bearing capacity to support large loads. We can also use it to measure its deflection under lateral load.  There  are  two  tests:  the  axial  static  pile  load  test (Kentledge)  and  the  two-directional  static  pile  load  test (Bidirectional).  T-Z  curve  as  the  result  analysis  based  on  the instrumented  pile  test  data  describes  the  load  distribution  and mobilized skin friction along with the pile. Numbers of Vibrating Wire  Strain  Gauge  (VWSG)  mounted  in  several  depths  of  the bored  pile  and  two  tell-tale  on  top  and  toe  of  the  pile  used  as primary  data  in  this  research.  This  research  to  determine  the different  distribution  of  mobilized  skin  friction.  The  pile  from two different pile load test methods from the calculated t-z curve as  the  study  developed  from  both  methods  of  pile  test.  The research results that the kentledge system has bigger mobilized skin friction than in bidirectional test.
Performance Analysis Of “Toga” Foundation With Cap On Thick Soft Soil Based On Laboratory Models And Finite Element Analysis Melissa Kurnia; Paulus Pramono Rahardjo
U Karst Vol 4, No 2 (2020): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v4i2.1072

Abstract

Various alternative foundations are offered depending on soil conditions from the results of soil investigations. In difficult soil types such as thick, soft soil layers, pile foundation is generally used to avoid the excess settlements, but deep foundations for small buildings are not the right solution when viewed from a cost perspective. One of the more economical foundations is to use the” toga” foundation, with a plate on top and a caisson underneath where the caisson can be inserted into the soil with an open end. Through this study, the carrying capacity of the” toga” foundation will be analyzed. Then the foundation will be made on a laboratory scale and tested with axial load. The load and deformation relationship were analyzed using PLAXIS 3D analysis. It can be concluded the performance of the ”toga” foundation on thick, soft soil can be used for two-floored buildings
Load Transfer On Bored Pile Foundation Instrumented With Fiber Optic And Concrete Quality Analysis Kevin Martandi Setianto; Cecilia Lauw Giok Swan; Paulus Pramono Rahardjo
U Karst Vol 5, No 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3933.927 KB) | DOI: 10.30737/ukarst.v5i2.1584

Abstract

The problem in the construction method of the bored pile is the contamination of mud or the other contaminant that can cause the modulus of elasticity of concrete to decrease. This research determines the modulus of concrete on a bored pile foundation instrumented with fiber-optic (FO) with a manual calculation based on strain data during loading test, validated with the results of research in the laboratory and numerical analysis. Fiber optic was used to measure the strain along with the pile during the loading test. The bored pile foundation is divided into 12 segments with the same strain characteristics, and then the modulus value is calculated. The result is the modulus value of each segment is different, and the value of the modulus changes along with the increase in strain; the modulus will decrease as the strain increases. This differs from the theory that the modulus has a fixed value approximated by empirical equations. Made a cylindrical concrete sample on both sides, which installed a FO to record the strain during the loading test. The result is true that the modulus is not constant but decreases as the strain increases. It is shown in the result of analysis to fiber-optic measurement data. Created a model in Plaxis2D for validation, and the results are not much different from the manual calculation.
Investigation of Twin Tunnel Deformation with Umbrella Grouting Protection & NATM Tunneling using 3D Finite Element: Case Study Cisumdawu Tunnel Wellyanto Wijaya; Paulus Pramono Rahardjo; Aswin Lim
U Karst Vol 5, No 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5437.709 KB) | DOI: 10.30737/ukarst.v5i2.1977

Abstract

Cisumdawu Tunnel is a twin tunnel 472 m long located in Sumedang. Twin tunnel construction can cause additional ground settlement and tunnel deformation. The tunnel construction method used is the New Austrian Tunneling Method (NATM) and umbrella grouting protection system. The principle of NATM is to maximize surrounding soil capacity to support its weight and balance the stresses around the tunnel. Investigation of tunnel deformation is important to know tunnel structure behavior and avoid possible failure. This research aims to know tunnel deformation and the effect of twin tunnel construction on the deformation and ground settlement. The data used such as tunnel geometry, monitoring data, pressuremeter test, and the drilling test. The 3D analysis will be performed for a single tunnel and twin tunnel using Midas GTS-NX, and monitoring data will be used for verification analysis. The 3D FEM help to model the soil condition and construction stage according to the actual condition. The analysis results show the maximum tunnel deformation that occurs from the beginning of the tunnel construction is 12.64cm. If the deformation starts to be calculated following the monitoring reading time, after the excavation at the monitoring point, the maximum deformation of the analysis results is 3.3&4.4cm, where the monitoring shows maximum deformation of 3.3&4.3cm. Through the results, it can be said that the analysis using 3D FEM with pressuremeter test parameter represents actual conditions. Twin tunnel construction side-by-side increases ground settlement and lateral tunnel deformation significantly. Hence, it shows that tunnel analysis using 3D FEM recommends for future investigation of tunnel deformation.
Investigation of Pile Behavior Toward Abutment Construction using PLAXIS 3D: Case Study on Lembak Bridge Clinton Girsang; Paulus Pramono Rahardjo; Aswin Lim
U Karst Vol 5, No 1 (2021): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3697.565 KB) | DOI: 10.30737/ukarst.v5i1.1012

Abstract

Soil  as  a  subgrade  foundation  under  embankment  construction often  creates  problems  in  terms  of  stability  and  settlement. Therefore, it needs improvement by using preloading embankment. This article presents the investigation of pile behavior towards two scenarios  of  abutment  construction  using  Plaxis  3D,  a  three- dimensional  finite  element  program.  The  use  of  two  scenarios  of analysis was Method A. The abutment construction phase conduct without using a preloading embankment, and Method B, where a preloading  embankment  constructs  before  the  abutment construction.  The  case  study  location  at  the  Lembak  bridge. Compare  the  analysis  results  with  the  measured  data.  Results showed that Method A and Method B's pile deflection yielded four times  and  one  point  six  times  larger  than  the  measure  data, respectively.  Hence,  it  indicates  that  Method  B  recommends  for future construction of bridge abutment.
Repair Performance Landslide and Slope Using Bore pile and Ground Anchor on Cipali Toll Road Km 103 Akhmudiyanto Akhmudiyanto; Paulus Pramono Rahardjo; Rinda Karlinasari
U Karst Vol 5, No 2 (2021): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4274.89 KB) | DOI: 10.30737/ukarst.v5i2.1583

Abstract

One of the causes of on-road collapse slopes is traffic load. Slope failure by road loads usually occurs due to several factors such as soil type, rainfall, land use. This study aims to determine landslide and slope repair performance using bore pile and ground anchor on Cipali Toll Road KM 103. The research method used in this study is the Finite element method. In this research, data collection, modeling parameter determination, slope stability analysis, slope reinforcement analysis, and reinforcement design were carried out with variations in bore pile and ground anchor dimensions. The software program used is a finite element program in the form of PLAXIS to analyze slope stability and estimate the slope failure area. The result of the study is that the R-Value inter is 0.25 with a 1.0341 safety factor. Best repair performance obtained from the addition of reinforcement with ground anchor 2 layer on bore pile 2 with a distance of 2 meters increased the safety factor to 1,913; Borepile capacity calculation with the calculation of normal force and moment iteration, the largest occurs in the DPT (Retaining Wall) stage with a normal load of -37.9 and a moment force of -471.15 which is still able to be borne by bore pile 1. The result of this study is expected to be benchmark and repair material to improve slope stability at km 103 Tol Cipali
Study of Anisotropy Characteristics of Bogor Volcanic Soil Yusi Sulastri; Paulus Pramono Rahardjo
U Karst Vol 5, No 1 (2021): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2700.687 KB) | DOI: 10.30737/ukarst.v5i1.1137

Abstract

Anisotropy in soil results from the deposition process which describes the characteristics of the soil grains or is caused by stress or from the consequences of stresses caused during deposition and subsequent erosion. All soils behave in general anisotropy and some exhibit undrained shear strength. This study conducted 2 tests, namely the first field testing with original soil samples in the form of CPTu and dilatometer. The CPTu test's objective is to determine the vertical soil parameters, while the dilatometer is to determine the horizontal soil parameters. This study indicates that the indication of anisotropy in all shear strength tests is evident in the results of the CPTu test and the Dilatometer test. TX - UU and consolidation show that the horizontal shear strength (Suh) is greater than the vertical slope shear strength (Suv). In this case, the ratio obtained for shear strength is Suh = 1.3 Suv. And from the results of the consolidation test in the laboratory, it was found that the horizontal compression index parameter  (Cc horizontal) was greater than the vertical (Cc vertical) and the horizontal coefficient of consolidation (Ch) is greater than the vertical coefficient of consolidation (Cv).
Evaluating Liquefaction Phenomenon Of Silty Sand Using Piezocone Penetration Test (CPTu) Albert Johan; Paulus Pramono Rahardjo; Budijanto Widjaja
U Karst Vol 6, No 1 (2022): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3773.405 KB) | DOI: 10.30737/ukarst.v6i1.2118

Abstract

Most investigations into liquefaction have focused on clean sandy soils, with time, evidence has grown that liquefaction is often associated with silty sand material. Sibalaya Village, which suffered the greatest damage from the Palu-Donggala earthquake, is dominated by silty sand material. Related to this issue, an experimental study is conducted in the laboratory to understand the behavior of excess pore pressure and the strength of the saturated silty sand under dynamic loading. The experimental study uses several sets of testing apparatus such as a shake table, chamber, and CPTu. The shake table provides a dynamic load for the soil sample. The chamber allows the field environment to be duplicated in the laboratory. The CPTu measures excess pore pressure and strength of the soil sample. The test results show that liquefaction can occur in silty sand material. However, the fine-grain particles cannot generate the overall pore water pressure in which the pore water pressure ratio can only reach 93% of the initial effective vertical stress. Liquefaction also generates increased pore water pressure and a decrease in soil strength. The increase of dynamic load will result in a shorter liquefaction starting time, and fine content strongly influences the pore water pressure behavior, especially on the rate of pore water pressure dissipation after liquefaction occurs. Therefore, based on this research, it is known that silty sand material can experience liquefaction and can have a longer liquefaction period due to its lower permeability.
Investigation of Pile Behavior Toward Abutment Construction using PLAXIS 3D: Case Study on Lembak Bridge Clinton Girsang; Paulus Pramono Rahardjo; Aswin Lim
U Karst Vol. 5 No. 1 (2021): APRIL
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v5i1.1012

Abstract

Soil  as  a  subgrade  foundation  under  embankment  construction often  creates  problems  in  terms  of  stability  and  settlement. Therefore, it needs improvement by using preloading embankment. This article presents the investigation of pile behavior towards two scenarios  of  abutment  construction  using  Plaxis  3D,  a  three- dimensional  finite  element  program.  The  use  of  two  scenarios  of analysis was Method A. The abutment construction phase conduct without using a preloading embankment, and Method B, where a preloading  embankment  constructs  before  the  abutment construction.  The  case  study  location  at  the  Lembak  bridge. Compare  the  analysis  results  with  the  measured  data.  Results showed that Method A and Method B's pile deflection yielded four times  and  one  point  six  times  larger  than  the  measure  data, respectively.  Hence,  it  indicates  that  Method  B  recommends  for future construction of bridge abutment.
Performance Analysis Of “Toga” Foundation With Cap On Thick Soft Soil Based On Laboratory Models And Finite Element Analysis Melissa Kurnia; Paulus Pramono Rahardjo
U Karst Vol. 4 No. 2 (2020): NOVEMBER
Publisher : Kadiri University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30737/ukarst.v4i2.1072

Abstract

Various alternative foundations are offered depending on soil conditions from the results of soil investigations. In difficult soil types such as thick, soft soil layers, pile foundation is generally used to avoid the excess settlements, but deep foundations for small buildings are not the right solution when viewed from a cost perspective. One of the more economical foundations is to use the” toga” foundation, with a plate on top and a caisson underneath where the caisson can be inserted into the soil with an open end. Through this study, the carrying capacity of the” toga” foundation will be analyzed. Then the foundation will be made on a laboratory scale and tested with axial load. The load and deformation relationship were analyzed using PLAXIS 3D analysis. It can be concluded the performance of the ”toga” foundation on thick, soft soil can be used for two-floored buildings