The GPS Data Campaign for the Slip Surface Estimation Ciloto Landslide Zone, West Java, Indonesia

Transcription

1 The GPS Data Campaign for the Slip Surface Estimation Ciloto Landslide Zone, West Java, Indonesia { Vera SADARVIANA, Hasanuddin Zainal ABIDIN, Djoko SANTOSO, Joenil KAHAR and Achmad Ruchlihadiana TISNASENDJAJA (Indonesia) Landslide prone area of Ciloto Ciloto zone consist of breccia rock, clay soil, silt soil Debris material

2 Mass Movement Indication in Ciloto Zone Morphology at Ciloto Area Unit I : Gunung Lemo Area Unit II : Pondok Cikoneng Area, Gunung Mas, Gunung Gedogan, and Gunung Joglok Unit III : Puncak, Jember Area Unit IV : Sindanglaya Area Unit V : Cempaka Slope Area, Tugu (Sugalang, 1989)

3 Methodology Geometric Method Static model : Status vector of horizontal and vertical displacement Kinematic model : Status vector of horizontal and vertical displacement Velocity and acceleration of material displacement A A B Y 1 Scarp 1 Y1 Y 3 Y3 B YPL : Slope Surface Equation Di : Distance between monitoring points and estimation point on slip surface X1 D1 X D YPL = U1 X + UX + U3 3 D3 X3 X Geometric Slip Surface position Ideal Physical Slip Surface Position

4 GPS Survey Monitoring Points Measurement by Geodetic Method Data Processing Kinematic Model Geometric Method Result : Geodesy Monitoring Points Coordinate Static Model Coordinates, Velocity and Acceleration of Geodesy Monitoring Points Slope Surface Profile Maximum-Minimum Function Velocity Trend Line Displacement vector Characteristic Approximation by Polynomial Function Geodetic Slip surface Estimation Landslide Type S : Sample location P : Piezometer location A-B- C-D : Cross section B.1, B. : Drilling point : debris slide : slope cutting : slumping : crack : river : fish pond, building : street : plantation, agricultural field

5 GPS SURVEY (00-005) GPS Survey Strategy GPS Measurement Campaign Measurement Method Differential Static Equipment Type Dual Frequency, Geodetic type Epoch 3 : 10 Mei 003 Data Type P and C/A code Carrier phase Epoch 4 : Mei 004 Epoch 1 : 11- January 00 Epoch : April 00 Epoch 5 : July 005 Duration 4-6 hour Epoch Interval 30 Elevation Mask 15 0 GPS Receiver type Receiver Unit Ashtech Z-XII3 3 Trimble 4000SSi 7 Leica SR9500 Leica SR50

6 Receiver 1,,, n Database : Antenna Height, Station Coordinate, Meteorology data GPS Data GPS Data Processing Conversion to RINEX Ephemerides correction Orbit computation Ionosphere analysis Observation data files Message data files Station coordinate Variance--Covariance matrix Variance Navigation data files Orbital Message Information Fiducially Points External Observation Single Point Solution Correction : Ionosphere, Troposphere, Earth Rotation, Relativistic, Cycle Slips Network Solution Statistical -Residual Residual -Error Error Ellipse Session Solution Estimation Parameter Process Ambiguity Update Cycle Slips correction Kinematic Model Equations (Yalcinkaya dan Bayrak, Bayrak, 004) : 1 E =E + (t i t i 1 )V Ej + (t i t i 1 ) a Ej 1 N (j i ) = N (j i 1) + (t i t i 1 )V Nj + (t i t i 1 ) a Nj 1 (i ) ( i 1) h j = h j + (t i t i 1 )Vhj + (t i t i 1 ) a hj (i ) j ( i 1) j Calculation of vector status prediction (scalar, velocity and acceleration) by Kalman Filtering Method

7 Kalman Filtering _ Y i,1 E N h V I 3, 3 E = V N = 0 3,3 0 3, 3 Vh a E a N a h i,1 E N h (t i t i 1 ) I 3,3 (t i t i 1 ) I 3,3 VE I 3, 3 I 3,3 (t i t i 1 ) V N Vh 0 3, 3 I 3, 3 a E a N a h (i 1),1 QYi,Yi = Ti,(i 1) QY (i 1),Y (i 1)TiT,(i 1) Lˆi,1 = Li,1 + v Li,1 = Ai,i Yˆi,1 v Li,1 = Ai,i Yˆi,1 Li,1 Result-1 Status vector of horizontal and vertical displacement Quantification of material displacement Comparation of displacement characteristic of landslide zone common with single sliding head, depletion zone (in middle), accumulation zone (foottoe) to find movement mechanism single/succesive/multiple/retrogressive sliding Comparation between horizontal and vertical (negative-positive) displacement of monitored point terain profile to find minor scarp position, subsidence & bulging translational/rotational slide

8 Kinematic M. : Cumulative Horizontal Displacement Kinematic M. : Cumulative Vertical Displacement Epoch 1- Epoch -3 Epoch 3-4 Epoch 4-5 Top of Landslide zone Middle of Landslide zone Toe of Landslide zone Result- Kinematic Model Velocity and acceleration of material displacement High horizontal velocity in depletion zone High vertical velocity in head (vertical -) and accumulation zone (positive +)

9 Illustration of Horizontal Displacement Geometric Height (m) Vertical profile Top of Landslide Zone Middle of Landslide Zone Toe of Landslide zone Horizontal Distance (m)

10 Velocity Displacement (Horizontal) Epoch 1- Epoch 3-4 Horizontal Displacement Epoch -3 Epoch 4-5 Horizontal Velocity Velocity Displacement (Vertical) Epoch 1- Epoch 3-4 Vertical Displacement Epoch -3 Epoch 4-5 Vertical Velocity

11 Vertical displacement (m)and velocity (m/month) Relation of Displacement and Velocity h+ h Horizontal displacement (m)and velocity (m/month) Displacement (Polynomial) Velocity (Polynomial) Discussion Vector Status of Position and Velocity Evacuation area Position of instability point (subsidence and bulging) Position of stability point (breakline) New Minor Scarp Retrogressive indication New scarp caused new external factor

12 New Minor Scarp Cross Section Line 4 3 1

13 Cross Section Line 1st Vertical surface Profile Velocity Trend Line (VTL) per point Approx. Surface from kinematic model Approx. Surface from Polynomial Function Slip Surface from intersection of VTL Cross Section Line nd Vertical surface Profile Approx. Surface from kinematic model Approx. Surface from Polynomial Function Velocity Trend Line (VTL) per point Slip Surface from intersection of VTL

14 Cross Section Line 3rd Vertical surface Profile Velocity Trend Line (VTL) per point Approx. Surface from kinematic model Approx. Surface from Polynomial Function Slip Surface from intersection of VTL Cross Section Line 4th Vertical surface Profile Approx. Surface from kinematic model Approx. Surface from Polynomial Function Velocity Trend Line (VTL) per point Slip Surface from intersection of VTL

15 Conclusion Characteristic Displacement Velocity is very slow 5 x x 10-7 mm/second Environment effect (rainfall water infiltration stress strain : subsidence/bulging) to material displacement can defined magnitude and direction New minor scarp give information of instability area of landslide zone Landslide Type Multiple compound (rotational and translational) debris slide

16 Landslide Hazard Mitigation Technical Engineering can applied with information : Priority location to minimize water infiltration Location of vulnerable area Direction and magnitude of velocity of material displacement External factor which influence to landslide zone can be defined well, like as river, spring, busy road, farm land