Geotechnical Investigation Report Templates

Solium Bore Consult Inc. Geotechnical Investigation Report

Dagupan Health Center Two (2) Storey Building

PROJECT INFORMATION Project Reference #: Project Name:

1305DE03 DAGUPAN HEALTH CENTER

Project Location: Client:

DAGUPAN ST. TONDO, MANILA DPWH North Manila Engineering District

Client’s Address: Consultant:

Solium Bore Consult Inc.

Contact Number:

1.0

DPWH Nagtahan, Sta. Mesa, Manila

09066892177

INTRODUCTION

The DPWH North Manila Engineering District, henceforth known as the Client, obtains the services of Solium Bore Consult Inc. to perform a subsurface investigation of a Proposed Two (2) Storey Building (Dagupan Health Center) located at Dagupan St., Tondo, Manila, Philippines. The objective of this report, by using the soil samples obtained underneath the site, is to provide geotechnical assessments based on the laboratory tests results. For

an

elaborate

and

systematic

plan of action

for

the

foundation,

recommendations will be provided on the following: Evaluation of the general suitability of the site for the proposed project. Anticipating and provision against difficulties that may ascend during construction due to ground and other local conditions. Attainment of physical and mechanical properties of soils for sufficient and economic design.

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Solium Bore Consult Inc. Geotechnical Investigation Report

Dagupan Health Center Two (2) Storey Building

Knowledge of groundwater conditions. Knowledge of the suitability of materials for construction General guidelines and strategies in the implementation of the construction procedures. Allowable bearing capacities of probable foundations

2.0

SCOPE OF WORK SUMMARY

A borehole is drilled within the vicinity of the proposed building. Standard Penetration Testing (SPT) is performed every 1.50 meters and core samples are taken in each interval. The borehole reaches a depth of 12.00 meters for good measure of the underlying material. The samples are subjected to routine laboratory tests to determine the classification of the materials using the Unified Soil Classification System (USCS) and their corresponding engineering properties. 2.1 DETAILS OF FIELD WORKS Table 1. Summary of field works Borehole No.

Drilling Depth (m)

1

12

No. of Samples SPT Coring 8 0

2.2 DETAILS OF LABORATORY WORKS Table 2. Summary of laboratory works Laboratory Test

No. of Samples

Particle Size Distribution Moisture Content Atterberg Limits Unified Soil Classification System

8 8 8 8

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Solium Bore Consult Inc. Geotechnical Investigation Report

3.0

Dagupan Health Center Two (2) Storey Building

GENERAL GEOLOGY AND SITE CONDITION

3.1 General Area The project area is located in Dagupan St. Tondo, Manila; the location is undoubtedly underlain by alluvial soils. The general topography was relatively flat surface. An unlined creek was located near the site at a distance approximately 240 meters. (Refer to Figure 1).

Figure 1. General Location (Google Earth) 3.2 Site Specific The proposed building is located in a crowded and with an existing structures area. Since the location of the structure is not on the list of the flood prone area made by the MMDA and Project NOAH researchers in Manila City, it is free from flooding, hence the water level will not reach into the grade elevation.

3.3 Seismicity It has been predicted by the study made by PHIVOLCS, the MMEIRS, that an earthquake with a magnitude of 7.5 may occur within this era, when the West Valley fault moves. By using Google earth, it was measured to have an

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Solium Bore Consult Inc. Geotechnical Investigation Report

Dagupan Health Center Two (2) Storey Building

approximate distance of 12 km from the site to the nearest line of the West valley Fault.

4.0

METHODOLOGY OF THE INVESTIGATION

4.1 FIELD SAMPLING & TESTING The boreholes are advanced by rotary drilling and wash boring method. Alternately with these methods, SPT is conducted at every 1.5 meter depth interval on soil layer, while rotary drilling on hard materials down to the bottom of the hole. Protective casings are inserted around the hole with a drop hammer to prevent materials from collapsing. The boring operation entails the following phases:

4.1.1 DRILLING WORKS a) Rotary Drilling A method employed when hard materials are encountered or where the N-value exceeds fifty (50). Under rotary action, the 46 mm diameter core bit is advanced into the rock with core runs between 1.00 to 1.50 meters. b) Wash Boring A process in advancing the borehole by applying an up and down twisting motion of a drill or chopping bit attached to the ends of drill rods while simultaneously allowing a stream of water pumped through the rods to the soil. The combined action of the water jet and chopping loosens the soil and is flushed to the surface. c) Standard Penetration Test (ASTM-D1586) The main sampling procedure conducted at every 1.50 meter depth interval using a Donut free fall type of hammer. It involves placing a 50.80 mm (O.D.) diameter split spoon sampler with the drilling rod into the ground at the bottom of the

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Solium Bore Consult Inc. Geotechnical Investigation Report

Dagupan Health Center Two (2) Storey Building

borehole. The hammer weighs 63.50 kg and is dropped a distance of 762 mm to produce a theoretical input driving energy (Ein) of 473.28 Nm. The number of blows to penetrate every 150 mm interval is recorded successively until the third interval is penetrated. The first interval blow count is considered as the seating drive and is discarded. The last two blow counts from the second and third intervals are added to give what is known as the N-value. Disturbed soil samples obtained by the split spoon were collected for visual inspection and laboratory testing. d) Ground Water Level This measurement is done by lowering a weighted tape down the hole until water contact is made. Readings are made after water is allowed to stand for a minimum period of 12 hours following completion of the drilling. The observation made during this period is assumed as the ground water level.

4.2 DETAILS OF LABORATORY WORKS The following laboratory tests are performed in accordance with the specified procedures from the American Society for Testing and Materials (ASTM). Appropriate test procedures are referenced in ASTM Manuals for the soil tests discussed in the following sections:

a) Natural Moisture Content (ASTM-D2216) This test is also known as water content. It is the ratio expressed as a percentage of the weight of water in a given mass of soil to the weight of the solid particles. b) Grain Size Analysis of Soils (ASTM-D422)

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Solium Bore Consult Inc. Geotechnical Investigation Report

Dagupan Health Center Two (2) Storey Building

A process wherein the proportion of each grain size present in a given soil sample (grain-size distribution) is determined. The grain- size distribution of coarse – grained soils is determined directly by sieve analysis, while that of fine-grained soils is determined indirectly by hydrometer analysis. The grain-size distribution of mixed soils is determined by combined sieve and hydrometer analyses. c) Atterberg Limits of Soils (ASTM-D4318) A procedure that consists of several parameters that are primarily water contents which define the limits of various stages of consistency for fine-grained soils. The liquid limit (LL) and the plastic limit (PL) define the upper and lower limits, respectively, of the plastic range of a soil; the numerical difference between these two limits expresses the plasticity of a soil and is termed the plasticity index (PI). d) Classification of Soils for Engineering Purposes (ASTM-D2487) In general, soils are classified based on the Unified Soil Classification System (USCS). In this system, soil falls within one of the three major categories: coarsegrained, fine- grained, and highly- organic soils.

5.0

OBSERVATION OF RESULTS

The table below shows the summary results of the borehole. The profiles of the index properties and in-situ moisture content of each borehole are also illustrated.

DEPTH

NVal ue

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USC S

DESCRI PTION

BOREHOLE CONSISTE NCY

INDEX PROPERTIES

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Solium Bore Consult Inc. Geotechnical Investigation Report

0.00 1.50

13

SCSM

1.50 3.00

22

SCSM

3.00 4.50

3

SM

4.50 6.00

3

6.00 7.50 7.50 9.00 9.00 -10.50 10.50 12.00

Dagupan Health Center Two (2) Storey Building

Silty clayey SAND with gravel Silty clayey SAND with gravel Silt SAND

MEDIUM DENSE

CL

Sandy LEAN CLAY

SOFT

7

CL

Sandy LEAN CLAY

MEDIUM STIFF

59

GC

VERY DENSE

67

SC

72

SC

Clayey GRAVEL with sand Clayey SAND with gravel Clayey SAND with gravel

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MEDIUM DENSE

VERY LOOSE

VERY DENSE VERY DENSE

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Solium Bore Consult Inc. Geotechnical Investigation Report

Dagupan Health Center Two (2) Storey Building

6.0 ENGINEERING ANALYSIS AND CONSIDERATIONS 6.1 SITE CONDITIONS The borehole shows sand deposits found in the surface layer, described by mostly sand in varying portions of fine-grained materials. There is irregularity with increasing depth; a deeper soil layer may less dense compare to shallower layers. This just confirms the predicted geology of the dynamic alluvial depository area. With the inconsistencies of the surface soils, it is highly likely that the site will experience differential settlement. After the first 7.5 meters, the soils encountered to be competent layers. Since these soil types are potentially liquefiable, the existence of alluvial soils on the surface is also cause for immediate concern. These layers warrant a closer inspection prior to recommending foundation schemes.

6.2 LIQUEFACTION POTENTIAL In assessing the possible of the soil for liquefaction, the simple criteria provided by the National Structural Code of the Philippines, (NSCP) 2010, Section 303.4 is used. Soils conforming all three of the following provisions will be considered liquefiable: 1) Shallow ground water, two meters or less 2) Unconsolidated saturated alluvium (N