SBEQ 1112 CONSTRUCTION TECHNOLOGY I SITE WORKS SITE
SBEQ 1112 CONSTRUCTION TECHNOLOGY I SITE WORKS SITE INVESTIGATION AND SOIL INVESTIGATION Mr. Syamsul Hendra Bin Mahmud Department of Quantity Surveying Faculty of the Built Environment Universiti Teknologi Malaysia
SITE WORKS Soil Investigation Site Investigation SITE WORKS Preliminaries Works
SITE INVESTIGATION • Site investigation is a systematic process to collect and record all the necessary data which will be needed or will help in the design and construction processes. • It is been done by providing a sketch with all annotated and dimensioned plans and sections. • It should include any elements on adjacent sites which may affect the proposed works. • In the same time, anything appertaining to the proposed works which may affect an adjacent site should also be recorded.
SITE INVESTIGATION • Site investigation is important to – Describe and establish the geological history of the site and the nature of the present soils. – Determine the ground water table. – Recover soil samples (disturbed or undisturbed) for laboratory test. – Carry out in situ test for soils. • Sources of preliminary information – – – Topographical maps and plans. Geological maps. Statutory or authorities maps and records Aerial photographs Etc.
SITE INVESTIGATION • Site investigation process Table Study Site Visit Ordinance Map, Geological data, Previous projects, etc Layout sketch, existing services, access to site, nearest town, etc Site Report Detail report consisting geological report, soil data, etc
SITE INVESTIGATION • Additionally, it is very important for the contractors to visit the site. For example, the types of vegetation are an indication of the nature of the sub-soils and/or rocks. This information is crucial for foundation’s design. • Any site investigation is carried out in a series of stages and BS Code of Practice: Site Investigation (BS 5930) sets these out clearly typical flow diagram showing the suggested sequence of events. • A site visit report is divided into several sections and the details may includes location, access to site, availability of space, services, site clearance, demolition, local conditions, etc.
SITE INVESTIGATION EDIT GAMBAR
SOIL INVESTIGATION • The soil investigation process is related to the subsoil beneath the site under investigation and could be part or separate from the site investigation. • Aims: – To identify the suitability of the site for the project. – To identify an economic foundation design. – To identify the difficulties which may arise during the construction process. – To identify the cause of all changes in subsoil conditions.
SOIL INVESTIGATION • The soil investigation involve physical, chemical and general characteristics test of the soil sample. • Soil samples: – Disturbed Soil Samples – Undisturbed Soil Samples • The test results of soil samples are usually shown on a drawing which gives the coordinates of each sample and test results in the form of a legend or section.
SOIL INVESTIGATION • Soil samples: – Disturbed soil samples: soil samples obtained from boreholes and trial pits. The method of extraction disturbs the natural structure of the subsoil but such samples are suitable for visual grading, establishing moisture content and some laboratory test. Disturbed samples should be stored in labeled air tight jars. – Undisturbed soil samples: soil samples obtained using coring tools which preserve the natural structure and properties of the subsoil. The extracted undisturbed soil samples are labeled and laid in wooden boxes for dispatch to a laboratory for testing. This method is suitable for rock and clay subsoil.
SOIL INVESTIGATION • Method chosen for soil investigation methods depend on several factors: – Size of contract. – Type of proposed foundation. – Type of sample required. – Type of subsoil which may be encountered. – Expertise of the staff • General methods: – Foundations up to 3 m deep – trial pits – Foundations up to 30 m deep – borings – Foundations over 30 m deep – deep borings
SOIL INVESTIGATION TRIAL PITS HAND AUGER HOLES • in dry ground which requires little or no temporary support to sides of excavation. • aim at locating underground services. • advantages: subsoil can be visually examined in-situ where both disturbed and undisturbed samples can be obtained. • in dry ground but liner tubes could be used if required to extract subsoil samples at a depth beyond the economic limit of trial pits • advantages: Cheaper and simpler method of obtaining subsoil samples than the trial pit methods.
SOIL INVESTIGATION EDIT GAMBAR TRIAL PITS
SOIL INVESTIGATION EDIT GAMBAR HAND AUGER HOLES
SOIL INVESTIGATION • The properties of the soil must be assessed before any foundations for a building or structure can be design. • Soil assessment can include classification, grading and tests to establish shear strength and consolidation. • BS 1377 : Methods of test for soils for civil engineering purposes describe several types of soil test. • The soil can be classify based on the geological origin, physical properties, chemical composition and particle size. • The particle size and physical properties of a soil is very important to the designer in order to design for the foundation.
SOIL INVESTIGATION • Soil assessment methods: EDIT GAMBAR – Standard Penetration Test • This test measures the resistance of a soil to the penetration of a split spoon or split barrel sampler driven into the bottom of a bore hole. • The sample soil is driven into the soil to a depth of 150 mm by a falling standard weight of 65 kg falling through a distance of 760 mm. • The soil sample then driven into the soil for another 300 mm and the number of flows counted up to a maximum of 50 blows. • The relative density of the soil can be derive from this test.
SOIL INVESTIGATION • Soil assessment methods: EDIT GAMBAR – Vane Test • This test measures the shear strength of soft cohesive soils. • The steel vane is pushed into the soft clay soil and rotated by hand at a constant rate. • The amount of torque necessary for rotation is measured and the soil shear strength are calculated. • Formula: S = M/K S = shear value in Kn/m 2 M = torque required to shear soil K = constant for vane (3. 66 D 3 x 10 -6) D = vane diameter
SOIL INVESTIGATION • Soil assessment methods: EDIT GAMBAR – Unconfined Compression Test • This test can be used to establish the shear strength of a non-fissured cohesive soil sample using portable apparatus either on site or in a laboratory. • The 75 mm long x 38 mm diameter soil sample is placed in the apparatus and loaded in compression until failure occurs by shearing or lateral bulging.
SOIL INVESTIGATION • Soil assessment methods: – Laboratory Test • This test are use to identify and classify soils with regard to moisture content, liquid limit, plastic limit, particle size distribution and bulk density according to BS 1377.
SOIL INVESTIGATION • REFERENCES – Chudley, R. and Greeno, R. (2007) Construction Technology, 4 th Edition, Pearson Education Limited, England. – Chudley, R. and Greeno, R. (2006) Building Construction Handbook, 6 th Edition, Butterworth. Heinemann, England.