Geology Trip Full Report

1.0 INTRODUCTION The project of geology is to fulfill the mark requirement for geology project. The project task learning is to study and observe the geological structure and obtained the data of dip direction, dip angle and slope angle from the site visit. Structural geology is the study of the process that result in the formation on geologic structure and how these structure affect rocks. Structural geology deals with a variety of structural features that can range in size from microscopic to large enough to span the globe such as mid-oceanic ridges. The site visit is held at Ayer Hitam and Pulau Mawar. During the site visit at Ayer Hitam, student was asked to obtain the data of slope angle, dip direction and dip angle to analyze the geological structure that exist in that area. It also give exposure to student about real rocks and classification of rocks based on the texture and other crucial characteristic. Students also learn and obtain the knowledge on types of rock deformation and how to determine the deformation. The rebound hammer test also conducted. These data is important in order to identify type of failure that occur and factors that contribute to the failure and to study the degree of rocks hardness in these different places. In Pulau Mawar site visits shows that there is different types of rock between these two site location which will be discuss later. During at Pulau Mawar, the same task is held which is to get the data for dip angle, dip direction and slope angle. An analysis of geological failure will be done. The rebound hammer test also conducted. These data is important in order to identify type of failure that occur and factors that contribute to the failure.

2.0 OBJECTIVE a) To recognize, identified and observed distinguishing mineral/rocks and its feature in fields. b) To record and plot the structural geology data. c) To identify the major and minor discontinuities set, plot the great circle of discontinuities and analyze the failure modes. d) To identify which continuities that has some potential to fail in fields. e) To identify the rock slope stabilization technique in the field.

3.0 LITERATURE Mineral And Rock Minerals are formed in various ways and different conditions. Most of the minerals require thousands of year to develop and others need just a few years. There are few cases that need only a few hours to develop. The mineral formations takes places either in the molten rock or magma, near the Earth surface or deep in the Earth crust as a result of transforming. Minerals occur naturallyas inorganic solids. They have a specific internal structure that is their atoms are precisely arranged into a crystalline solid. They have a chemical compositiont hat varies within definite limits and can be expressed by chemical formula. They have definite set of physical properties (hardness, cleavage, crystal form etc) that result from their crystalline structure and composition. Rock is defined as a mixturesformed of aggregates of one or more minerals (aggregate of minerals). Rocks can be formed by many different processes such as: a) Igneous-Crystallization of a melts –magma (intrusive) and lava (extrusive) b) Sedimentary-Solidifying sediments like sand or clay c) Metamorphic-Re-crystallizing previously formed rocks in the solid state d) Hydrothermal-Some are formed by crystallization from hot aqueous fluids

Civil engineers have to deal with rockand soilsduring various stages in the process of construction, build a road, a tunnel,aslopeor a dam. From the stage of planning to the execution of a construction project, the engineer must have a basic appreciation of the engineering behavior of rocks and soils under various conditions. It becomes imperative for engineers to have some basic geological appreciation of rocks and soils in order to understand the engineering limits to which these materials can be subjected.

Weathering Weathering is a general term describing all changesthat result from the exposure of rock materials to the atmosphere. It is one of the most important geologic processes that leads to the disintegrationor decompositionof geologic deposits. Weathering occurs because most rocks are in equilibrium with higher temperatures and pressure deep within the Earth. Rocks which are deeply buriedlies in a different environment physicallyand chemicallythan those exposed on the earth's surfaceand therefore changes will take place to accommodate thesenew conditions. If they are exposed to the much lower temperaturesand pressuresat the surface, to the gases in the atmosphere, and to the elements in water, they become unstableand undergo various chemical changes and mechanical stresses. As a result, the solid bedrock breaks down into loose, decomposed products. Rock fragmentsproduced by weatheringare removed by erosionand the general term for both weatheringand erosionis known as denudation. There are two classificationof weathering processes which is;

a) Physical weathering b) Chemical weathering 1. Phisical Weathering Physical weathering is the mechanical breakdown of the rocks into smaller fragments without undergoing a change in chemical composition. Physical forces that contribute to this type of weathering are: a)Frost action b) Unloading c) Saline crystal growth d) Alternate heating and cooling e) Organic activities

2. Chemical Weathering Chemical weathering reactions produced minerals of increased volume. Decomposition produces a chemical breakdown of rocks, which may destroy the original mineral sand produce new ones while expansion will result in the physical disintegration or break up of rock. Common processes of chemical weathering reactions are: a) Oxidation b) Hydration c) Hydrolysis d) Dissolution Geological Structure Over the past thousand million years of Earth history the crust of the Earth has been mobile. As a consequence many of the rocks that we see now near of at the surface, no matter what their origin have been squashed, stretched or fractured; they have been deformed. Deformation arises because large parts of the Earth (lithospheric plate) have been moving relative to each other throughout geological time. The movement of these plates generate stresses that lead to both compression (collide) and tension (break apart or stretched). The rocks comprising the crust respond to such stresses by undergoing changes of shape (strain), therefore various geological structures are developed which provide a record of type of deformation. Compressional, tensional and shearing forces acting on rocks may cause them to form: a) Fold b) Fractures c) Joints

Fold Folds is a bend or flexure in layered rocks. It is the most common kind of deformation in layered rocks usually well collision of developed in great mountain systems due to the collisions of tectonic plates. Upward folds are anticlines or downward synclines. An anticline is an up arched or convex upward fold with the oldest rock layers in its core. A syncline is a down arched or concave upward fold in which the youngest rock layers are in its core. They may be gentle, moderate or strong. Folds may be rounded or angular.

Figure 2.3.1: Syncline and anticline showing the axial plane, axis and fold limbs Fracture Faults are fractures which have had displacement of the rocks along them. The adjacent rock masses slipped past one another in response to tension, compression or shearing stress. Fault plane is the plane of dislocation along which movements occur during faulting. Fault commonly create zones of broken ground-weaker and less stable than the adjacent rock. Sudden movements along faults may cause earthquakes. Categories of faults: (a) Normal fault (b) Reverse fault (c) Lateral fault (d) Oblique slip fault

a) Normal fault Occurs most frequently in rocks that have been subjected to horizontal tensional force. One side of the layer move downwards relative to the other.

Figure 2.3.2: Normal fault

b) Reverse Fault Occurs when the crusts are compressed and one side of the layer moved upwards relative to the other.

Figure 2.3.3: Reverse fault

c) Lateral Fault Involves the horizontal movement along the strike of the fault plane.

Figure 2.3.4: Lateral fault

c) Oblique Slip Fault Combination of dip – slip and strike – slip movements

Figure 2.3.5: Oblique fault

Joints

These are rock fractures with no movement along them and tend to break a rock mass into a network of blocks. They are formed by tectonic stressing and are developed in nearly all rocks. Dominant fractures within sedimentary rocks are usually the bedding planes. Many bedding planes are very thin bands or partings of shale or clay between units of stronger rocks. Massive rocks have less fractures, joints or structural weaknesses.

Figure 2.3.6: Jointing in a folded stratum

Rebound Hammer Rebound Hammer caan be conducted using Schmidt's hammer (L-type). Test is simple and fast and equipmentsis portable. Test can be undertakenon the surface of blockor core samplesand does not involve destruction of sample. Index value obtained is rebound number (R)which is a measure of the degree of hardness of rock surface. Value of Rcan be used to estimate the compressive strength of rock using the following equation:

Log10JCS = 0.00088(y)(R) + 1.01 (Franklin, 1989)

Where, JCS (MPa) is the compressive strength of rock surface; y (kN/m3) is unit weight of rock.

Figure 2.4.1: Example of testing rock using Rebound Hammer.

4.0 APPARATUS

Measurement tape Brunton compass

Marker pen Rebound hammer

5.0 METHODOLOGY

Procedure for Minerals and Rock Identification Before Trip a) Lecturer give explanation on geological history at this area at the class before went to trip. b) Lecturer explain about Minerals and rock from all spec During Trip a) By using observation method, find minerals and rock that had at there b) Snap photo of the related mineral and rock outcrop which present at site. After Trip a) Identify physical of mineral/rock surface such as: i) Physical properties of mineral ii) Structure iii) Grain/texture iv) Mineral composition v) Parent Rock vi) Color

Procedure For Identification Of Weathering Before Trip a) Lecturer will give explanation to identify types of weathering (physical and chemical weathering) present at site.. b) Lecturer will explain students to perform weathering profiling of the rock outcrop. During Trip a) By using observation method, find the rock that had weathering process b) Snap photo of the related weathering outcrop which present at site

After Trip a) Record and estimate types of weathering and weathering profile of the outcrop based on guidelines.

Geologic Agents Before Trip a) Lecturer will give explanation to identify the rock agent that occur in the world b) Lecturer will explain students the cause of geologic agent on the rock During Trip a) By using observation method, find the rock that had change because the geologic agent. b) Snap photo of the related weathering outcrop which present at site After Trip a) Estimate the geologic agent that occur at there and show in report the cause of geologic agent

Identifying The Geological Structure And Measurement Of Strike, Dip Direction, Dip Angle And Mode Of Failure Before Trip a) Lecturer will give explanation about strike, dip direction and dip angle. b) Lecturer will explain to student, how to get strike, dip direction and dip angle by using geology compass During Trip i) Dip angle

a) Takes the compass and put the down-side compass level with rock slope to find the slope angle or dip angle.

b) Make sure the value of the bearing dip angle is in the left side. Read the value that we achieve. The bearing that we achieve is the steepness of the slope. The concept of the dip angle is the radian or bearing from horizontal level to the gradient of the slope rock. ii) Dip Direction a) The dip direction is the maximum angle of inclination downward that a vein or bed makes with a horizontal plane. b) To determine the dip direction, take a small rock or materials then laythe materials to the surface or slope rock. See the direction than the material fall based on gravity. So, the direction is the dip direction. (We can use water and see the flow of water) c) Draw the dip direction that we achieve. d) With compass, level compass to the North direction and see the valueof the bearing dip direction. Every strike or dip direction, the value mustbe determine from North. e) The dip direction also can determined by formula;

Dip Direction (DD) = Strike + 90°

f) That is the procedure to determined or measure the dip direction.

iii) Strike a) Strike is he bearing of a horizontal line in the plane of a vein, bed, or fault with respect to the cardinal points of the compass. b) With the dip direction value, we can get the value of strike. c) To determined strike, we can use the formula. Value of strike is 90°anticlockwise from the value of dip direction. d) The formula is ; Strike (s) = Dip Direction - 90°

e) Same as Dip Direction, strike direction can be drawing on the rock andtake the compass to get the value or bearing of strike from North direction. After Trip a) By using all the data, find the mode of failure and factor of safety for the rock slope b) Show all the calculation on the report Rebound Hammer.

Figure: Rebound hammer Method to use rebound hammer a) We have selected a rebound hammer appropriate to the type of rock tested, and we also have checked whether that it working correctly. b) Then we choose the suitable test locations and we tested it only on the smooth surfaces. c) After that we confined the readings of a test to an area which is not exceeding 300mm x 300mm. d) Then we have draw a regular grid of lines 30mm apart and take the intersection of the lines at test points. e) We have twelves reading at a location.

Procedure using rebound hammer a) The hammer was pressed against the rock. The plunger reacts against spring and the hammer was ready to be used. b) The hammer was pressed to the test location until the mass hammer impact against the surface through the plunger. c) Hammer was operated perpendicular to the surface horizontally. d) The button at the side of the hammer was pressed and the amount of rebound of mass , R from the indicator was read. e) By referring to the calibration curve on the standard steel anvil the compressive strength was read. f) Lastly, we have estimated the compressive strength with refer to the table given.

6.0 RESULT Pulau Mawar a) Mineral and Rock Identification No Rock picture 

1

   

2



    3



   

Properties Physical properties of mineral  Colour : brown & grey  Fracture : irregular breakage Structure  Rounded surface Grain/texture  Porphyritic texture fine grained Mineral composition  Potassium feldspar Parent rock  Igneous (extrusive) Physical properties of mineral  Colour : brown & grey  Fracture : irregular breakage Structure  Rounded surface Grain/texture  Porphyritic texture fine grained Mineral composition  plagioclase Parent rock  Igneous (extrusive) Physical properties of mineral  Colour : brown & grey  Fracture : irregular breakage Structure  Rounded surface Grain/texture  Porphyritic texture fine grained Mineral composition  plagioclase Parent rock  Igneous (extrusive)

4



    5



    6



   

Physical properties of mineral  Colour : brown & grey  Fracture : irregular breakage Structure  Rounded surface Grain/texture  Porphyritic texture fine grained Mineral composition  plagioclase Parent rock  Igneous (extrusive) Physical properties of mineral  Colour : brown & grey  Fracture : irregular breakage Structure  Rounded surface Grain/texture  Porphyritic texture fine grained Mineral composition  plagioclase Parent rock  Igneous (extrusive) Physical properties of mineral  Colour : brown & grey  Fracture : irregular breakage Structure  Rounded surface Grain/texture  Porphyritic texture fine grained Mineral composition  plagioclase Parent rock  Igneous (extrusive)

Weathering 

Weathering profile From our trip to Pulau Mawar, we can say that the rock structure at Pulau Mawar has three zone of weathering profile which is zone four, five and six.  Zone 4 - Poor quality rock mass : 30% to 50% rock (grade 1,2 or 3) - Corestones affect shear behavior of mass.  Zone 5 - Soil with corestones : less than 30% rock (grade 1,2 or 3) - Shearing can be effected through matrix - Rock content significant for investigation and construction.

 Zone 6 - Soil derived from in-situ weathering: 100% (grades 4,5 or 6) - May or may not have lost rock mass features completely.



Physical weathering -

Organic activities  



Activities of plant promote rock disintegration Pressure from growing wood widen as crack and contribute to rock breakdown

Chemical weathering -

Oxidation

  

Oxygen and air assisted by water combines with mineral to form oxides. Occur to rock and mineral Produce rusty, red brown rock



Spheroidal weathering

  

Produced rounded shape Weathering attacks an exposed rock from all side at once Exfoliation is a special type of spheroidal weathering.

Identifying The Geological Structure 

Fracture







Occur most frequently in rock that have been subjected to horizontal tension force One side layer move downwards relative to the other

Joints





Rock fracture without movement along them and tend to break a rock mass into a block. Formed by tectonic stressing and developed nearly all rocks.

Measurement of Strike, Dip Direction and Dip angle

Strike and dip is to describe the compass direction and the degree of inclination of a rock mass. Outcrop is an exposure of rock at the surface (or the area of a rock lying directly beneath a soil cover). Strike : the line performed by the intersection of horizontal plane and an inclined plane. Dip or dip angle : the maximum angular deviation of the inclined layer from horizontal. In other words, the maximal angle of slope of a tilted stratum measured directly ` downward from the horizontal plane. The direction of dip is perpendicular to the strike.

No 1

Type

Dip direction,(○)

Strike,(○)

Dip angle,(○)

Persistence,(m)

Apature,(mm)

Infilling

Roughness

Water

Joint

164

095

030

1.8

1

1

4

1

Joint

235

163

65

1.8

1

1

4

1

Joint

044

145

55

1.8

2

1

4

1

Joint

115

20

1.8

1

1

4

1

Joint Slope

020 84

71 54

1.8

2

1

4

1

2 3 4 110

5 6

Height of slope (m): 8m Slope direction (o) : 226 o Slope dip angle (o) : 76 o

161 155

Identification of Mode of Failure 

Toppling Failure





Columnar structure separated by steeply dipping discontinuities

Plane failure

 

Pattern of discontinuities may be comprised of a single discontinuity Occurs when a mass of a rock in a slope slide down along a relativity planar surface failure

Rebound Hammer

Test ref.

Test

Recorded R

location

value

Mean R

Inclination

Corrected

Compressive

angle (°)

R

strength (N/mm₂)

1

Pulau

48

54

43

mawar

50

48

56

46

43

48

48.4

90

0

51

Ayer Hitam Mineral & Rock Identification During the site investigation at Ayer Hitam, the structure of the rock and the geological fractures have been observed. And, there some sample of rock have been collected and examine. From the observation, we can identified that most off the rock at Ayer Hitam is igneous extrusive and sandstone. Table below are some sample that have been collected. No. Rock 1.

2.

Properties  Physical properties of rock - Color: Grey, Brown - Fractures: irregular breakage  Structure: Irregular  Grain: Porphyritic, fine crystallite grains.  Mineral composition: Acid-Rhyolite  Parent Rock: Igneous rock (extrusive)

    

3.

    

Physical properties of rock - Color: White Grey - Fractures: irregular breakage Structure: Irregular Grain: Porphyritic, fine crystallite grains. Mineral composition: Pottasium feldspar Parent Rock: Igneous rock (extrusive) Physical properties of rock - Color: Black - Fractures: irregular breakage Structure: Irregular Grain: Porphyritic, fine crystallite grains. Mineral composition: Acid-Rhyolite Parent Rock: Igneous rock (extrusive)

4.

    

5.

    

Physical properties of rock - Color: Grey, Brown - Fractures: irregular breakage Structure: Irregular Grain: Porphyritic, fine crystallite grains. Mineral composition: Acid-Rhyolite Parent Rock: Igneous rock (extrusive

Physical properties of rock - Color: Grey, Brown - Fractures: irregular breakage Structure: Irregular Grain: Porphyritic, fine crystallite grains. Mineral composition: Acid-Rhyolite Parent Rock: Igneous rock (extrusive

Weathering At Ayer Hitam, the type of weathering that have been obtained are physical weathering. Physical weathering is the mechanical breakdown of the rock into smaller fragments without undergoing a changed in chemical composition.

No. Picture 1.

Type Of Weathering 

Alternate Heating & Cooling (Physical Weathering)

2.



Exfoliation (Physical Weathering)

Identifying The Geological Structure 

Fault

-

a fault is a planar fracture or discontinuity in a volume of rock, across which there has been significant displacement as a result of rock-mass movement.

Measurement of Strike, Dip Direction and Dip angle

Strike and dip is to describe the compass direction and the degree of inclination of a rock mass. Outcrop is an exposure of rock at the surface (or the area of a rock lying directly beneath a soil cover). Strike: the line performed by the intersection of horizontal plane and an inclined plane. Dip or dip angle: the maximum angular deviation of the inclined layer from horizontal. In other words, the maximal angle of slope of a tilted stratum measured directly ` downward from the horizontal plane. The direction of dip is perpendicular to the strike.

Table: Discontinuity Data sheet (Ayer Hitam) No

Type

Dip

strike

Dip angle,

Persistance,

Apature,

direction,

(o)

(o)

(m)

(Table 1)

Infilling

Roughness

Water

(o)

1

J1

54

326

46

1.10

2

1

4

2

2

J2

44

290

44

0.3

2

2

4

2

3

J3

34

269

48

1.2

1

1

4

2

4

J4

54

121

52

0.25

2

2

4

2

5

J5

46

325

38

2.3

1

2

4

2

Slope direction (o) : 346 o Slope dip angle (o) : 54 o Height of slope (m): 4m

Table: Percentage of pole gap Pole

Percentage (%)

Gap

1

20

20

2

40

40

3

60

60

Table: Modes of Failure Mode of

Joint Set and

failure

Data

Plane

Joint 1

Criteria i) 3460 + 20

(224/41)

Stability

366o/6o

Stable

3260

* Because it not

*Dip direction Joint = 224

full the

*Not in range= unsatisfied

requirement for

ii) 54> 41 > 30

plane failure

*in range= Satisfied Topping

Joint 1

i) 2240 + 180 + 10

(224/41)

54o

Stable

340

* Because it not

*Dip direction slope = 346

full the

*Not in range= unsatisfied

requirement for

ii) (90- 54) +30 < 41

plane failure

*Not follow the requirement *unsetisfied

Rebound Hammer

Test ref.

Test

Recorded R

location

value

Mean R

Inclination

Corrected

Compressive

angle (°)

R

strength (N/mm₂)

1

Air

38

58

49

hitam

50

51

44

(A)

44

52

45

47.89

90

0

44.8

Resistivity resistivity is a measure of how much the soil resists the flow of electricity. It is a critical factor in design of systems that rely on passing current through the Earth's surface. An understanding of the soil resistivity and how it varies with depth in the soil is necessary to design the grounding system in an electrical substation, or for lightning conductors. It is needed for design of grounding (earthing) electrodes for substations and High voltage direct current transmission systems. It can also be a useful measure in agriculture as a proxy measurement for moisture content. In most substations, the earth is used to conduct fault current when there are ground faults on the system. In single wire earth return power transmission systems, the earth itself is used as the path of conduction from the end customers (the power consumers) back to the transmission facility. In general, there is some value above which the impedance of the earth connection must not rise, and some maximum step voltage which must not be exceeded to avoid endangering people and livestock. At Pulau Mawar, there were some Master student who perform this test. They show us how to undergoes the testing for resistivity using the equipment that they brought from UTHM Lab. Picture Below shows the type of equipment and how to perform the resistivity test.

7.0 DISCUSSION Precaution step that we must alert is we have to handle the rebound hammer with care because it is really costly and a little bit heavy. The advantages of this rebound hammer test are it is simply to use. No need experience to conduct the test. Next, it is established uniformly of properties, the equipment is inexpensive and it is readily available Meanwhile the disadvantages of this rebound hammer test are it is only evaluating only the local point and layer of masonry to which it is applied. Next, no direct relationship to strength or deformation properties, unreliable for the detection of flaws. The disadvantages of rebound hammer are cleaning maintenance of probe and spring mechanism. At Ayer Hitam we took 9 data of 90° inclination angle and get the mean R is 54.1. From that we find the value of compressive strength from calibration curve on the standard steel anvil the compressive strength was read and we got 44.8 N/mm₂ . At ayer Hitam we couldn’t make the 0° inclination rebound test because there was only on the road pavement. we couldn’t get to higher ground to take data because it wasn’t save. At Pulau Mawar we also took 9 data for each inclination 0° and 90° . and for the average R we got 32 for 0° inclination and 42.8 for 90° . Thus, the compressive strength from calibration curve are 29.2 N/mm₂ for the 0° and 52N/mm₂

for the 90° inclination angle. The 0° test was

doing on the rock and the 90° was the test on the rock slope. Obviously, the compressive strength on the slope was higher than the rock. The rebound value can be measured discretionary, whereas the number of crushed specimens is limited. The combination of both methods is the best and most reliable procedure to determine the compressive strength of concrete structures the method does not damage the structure like the classical method, where cores must be taken for the evaluation of the compressive strength. The compressive strength from Ayer Hitam slope was lower than the compressive strength from Pulau Mawar rock slope. Both are igneous rock. This is because they have different mineral content. They also from different spot such as, Ayer Hitam is at the highground while rock at Pulau Mawar were at the beach. They were exposed to different type of weathering. the rock undergoes different process thus make them have different mineral content and different compressive strength.

8.0 ANSWERING ALL PROVIDED QUESTIONS 8.1 State name of rocks particularly at Ayer Hitam and Pulau Mawar. Solution: The name of rocks particularly at Ayer Hitam that we observe are sandstone, siltstone and shale while in Pulau Mawar is alluvium.

Figure 6.1.1: Rock at Ayer Hitam and Pulau Mawar

8.2 State the parent material of rock present at Ayer Hitam and Pulau Mawar. Solution: -

The parent material of rock present at Ayer Hitam are sand sediment for sandstone, silt sediment for siltstone, and clay sediment for shale while in Pulau Mawar are fine particles of silt and clay and larger particles of sand and gravel.

8.3 State geological structure that available at Ayer Hitam and Pulau Mawar. Solution: -

The geological structures that available at Ayer Hitam are strike and dip, fault, and joint while in Pulau Mawar are strike and dip, fault, joint, and fold.

Figure 6.3.1: Fault at air hitam

8.4 State rock testing to measure joint compressive strength of rock from surface. Solution: -

The rock testing to measure joint compressive strength of rock from surface are pointload index test, and Rebound hammer test.

Figure 6.4.1: Rebound hammer test

8.5 Explain types of rock slope stabilization which may be applied at Ayer Hitam and Pulau Mawar. Solution: -

Recommended types of rock slope stabilization which may be applied at Ayer Hitam and Pulau Mawar are rock face support method, rock reinforcement methods, and detailed drainage work on the rock face method.

-

First, for the rock face support method, a concrete or masonry wall may be necessary to sustain the load of a major rockslide, and is most efficiently used in conjunction with rock anchors. Less rigid, and possibly more economic buttressing systems include crib walling, soil or rock fill berms and structures built from stone-filled gabion baskets.

-

Second, for the rock reinforcement method, the simplest of these method is the use of steel dowel bars as shear keys, typically to knit together medium to thinly bedded material dipping parallel to the slope. Holes would be drilled normal to the bedding and the bars grouted in with any potential shear surface at mid depth. Dowels are unstressed and weak in bending and therefore would only be used where the discontinuities are narrow. A dowel bar would be 15 to 30 mm diameter and 1 to 2 m long.

-

Lastly, for the detailed drainage work on the rock surface method, small scale instability is in general mainly promoted by the wedge action of frost, ice and cleft water in nearsurface discontinuities. The effect of free water on the stability of a bolted block has already been indicated. To establish stable conditions, it is therefore essential and economical to use some form of slope drainage. Firstly, measures must be taken to prevent the infiltration of surface water in the vicinity of the slope. The most commonly used form of drainage is a ditch at the head of the slope. The ditch may re-channel an existing permanent flow or may simply collect upslope runoff. The construction of an impermeable lining reduces maintenance and minimizes infiltration.

9.0 CONCLUSION AND RECOMMENDATION CONCLUSION Thus as a conclusion of the two days geological site visit to Ayer Hitam and Pulau Mawar, we realized that the engineering geology has wide scope in civil engineering field and is very much important in both theoretical and practical point of view. Now, we have knowledge to identify and cause measure about such field. We are now, able to identify different type of rocks weather sedimentary, metamorphic or igneous and different types of mass movement activities, its cause and nature, slope stability measurement for stability analysis. The gain knowledge of rock mass rating and determining the quality, strength and class of the rock at the site. This geological site visit is more fruitful and from that we achieved knowledge and process of documentation of different geological activities, geological units, and technique of rock mass rating, and etc. It is better to say that Engineering geological site visit for a civil engineer is one of the most essential aspect for his skill, practical knowledge about the field and in overall career development.In short this visit gave us lots of ideas regarding engineering works and geology. We also gained knowledge to analyze the engineering significance of various landforms. So the visit was fruitful. RECOMMENDATION 1. The time for the trip is quite short. Therefore, we hope the next site visits of geology will have a longer time.

2. Visiting 2 different places give us more advantages. It helps us identifying different type of rock in different places which are on slope and seashore.

3. Early briefings help us to know what that we need to do at the site. Taking data of the dip and strike of the rock become easier.

4. The cooperation between group member and classmate make the site visit successfully. There are not a lot of problems before and during the site visit.

APPENDIX PULAU MAWAR

AYER HITAM