Môc lôc GMS Ben Luc Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 METHOD STATEMENT FOR REPLACEMENT SOIL TABLE OF CONTENTS I GENERAL II CONSTRUCTION III BORROW MATERIAL IV[.]
GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 METHOD STATEMENT FOR REPLACEMENT SOIL PHUONG THANH TRANCONSIN GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 TABLE OF CONTENTS I GENERAL II CONSTRUCTION III BORROW MATERIAL IV MAIN EQUIPMENTS PHUONG THANH TRANCONSIN GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 I GENERAL This method is a method of soft soil treatment, is replaced soft soil layer by suitable soil Common excavation will be classified as “Excavation of Unsuitable Material” when it is composed of: - Materials below the natural ground surface in embankment areas and, in excavation areas, below the grading plane or other limits shown in the Drawings or determined by the Engineer, that are unsuitable for the further use - Materials specified on the soft soil treatment Drawings as requiring excavation and replacement, and that are unsuitable for further use - Surplus material over the amount required for the construction of embankment, provided however that it is not material rendered surplus by reason of the Contractor having opened borrow pits solely for his own convenience; - Surplus topsoil over the amount reqiured for re use on embankments, other areas indicated on the drawings or as directed by the Engineer, provided that where the contractor has disposed of surplus topsoil and left in sufficient on site for re-use he shall make up the short fall at his own cost - Materials such as highly organic clays and silts, peat, muck, soil containing a large amount of roots, grass and other vegetal matters, domestic or industrial waste, might be classified as “unsuitable” under the Specification Section - Soils with a liquid limit exceeding 55% and a plasticity index exceeding 27% - Highly expansive soil (classification method may be either of the following: free expansion over 3%; or having an Activity Value greater than 1.0 or a degree of expansion classified by AASHTO T258 “Standard Method of Test for Determining Expansive Soils” or other equivalent specification as “Very High” or “Extra High” The Activity Value shall be measured by the Plasticity Ihdex/Percent Clay Size ratio) - Materials having hazardous chemical or physical properties - Soil that cannot be properly compacted in accordance with Specification requirements - Suitable materials that, in the opinion of the Engineer, were contaminated by the actions of the Contractor during excavation operations In such a case these materials will not be considered as unsuitable for purposes associated with payment PHUONG THANH TRANCONSIN GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 II CONSTRUCTION Preparation work Prior to excavation all site clearing shall have been completed in accordance with the appropriate specification to the satisfaction of the Engineer Before the start of any excavation the Contractor shall carry out a topographical survey of the area and prepare and submit the cross section and profile drawings to the Engineer for his approval These drawings shall be used as a basis for the computation of the actual volume of excavated materials Use of excavated material All materials removed from the excavation, that are evaluated by the Engineer as “suitable”, shall be used in the formation of the road embankment, sub-grade, shoulders, slopes, bedding, surcharge and counterweights, backfill for structures, topsoiling or for other purposes shown on the Drawings or as approved by the Engineer All excavations shall be finished to reasonably smooth and uniform surfaces Excavation operations shall be conducted so that material outside the limits of slopes will not be disturbed Dimensional tolerances: - Finished grades, alignment and formations after excavation shall not vary from those detailed in the drawings by more than 20 mm at any point - All exposed finished excavated surfaces shall be properly graded and uniform, and shall have sufficient slope to ensure that they are free draining and free from ponding during rainfall Removal unsuitable soil No materials shall be classified as unsuitable and remove from site without quantification by the Contractor and approval by the Engineer When material below sub-grade level in cut or below embankment foundation level is found to be unsuitable and the Engineer confirms it is to be removed, the soil remaining after the removal of the unsuitable material shall be compacted where practical to a depth of 20 cm and a density of 95 percent of the maximum dry density determined in accordance with AASHTO T99 Payment for such compaction shall be deemed included in the unit rate for excavation Unsuitable material shall be removed and disposed to disposal areas provided by the Contractor and subject to the approval of the Engineer The Contractor shall comply with all local environmental regulations when disposing of unsuitable material and shall include in his Environmental Management Plan all relevant details for the hauling and disposal of unsuitable materials PHUONG THANH TRANCONSIN GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 Backfilling On completion of the replacement soil, excavated areas shall be back-filled with approved material to the level of the finished ground surface 4.1 Soil backfilling Back-fill shall be placed in layers not exceeding 15 cm Initially and for any change in soil type, the Maximum Dry Density (MDD) shall be established in accordance with AASHTO T99 from at least three soil samples Compaction, based on at least one test per backfill layer, shall be 95% of the MDD so established Compaction method and equipment shall be suitable for use with the backfill material 4.2 Granular backfilling Granular backfilling required for specific structures or other locations detailed in the drawings or as required by the Engineer shall be placed in layers not exceeding 15 cm and compacted to 95% (for K95) of the maximum dry density determined according to AASHTO T99, as indicated on the Drawings The material shall be well-graded crushed or uncrushed gravel, stone, rock-fill or natural sand or a well-mixed combination of any of these Grading requirements for Granular Backfill shall be as follows: III - Maximum size cm - Passing 4.75 mm sieve 25% to 90% - Passing 0.075 mm sieve 0% to 10% - Liquid limit TCVN4197-95 30% max BORROW MATERIAL All suitable materials provided from borrow sources shall be used and placed to the grades, cross sections and other requirements indicated on the drawings subject to the approval of the Engineer During the operation of the borrow pit the Contractor shall ensure the pit remains in a safe properly drained condition The drainage shall be kept functioning and in as good condition as practicable and the sides and ends of borrow pits shall be maintained at the slopes included in the Contractor’s submission Where a borrow pit includes materials of distinctive types, excavation shall be carried out in a manner that ensures each type remains separate and that no mixing occurs Excavation shall also be carried out in such a way that excavated surfaces are free draining and that the as dug moisture content of borrow material remains unaffected PHUONG THANH TRANCONSIN GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+450 to Km 35+900 During excavation of the borrow pit temporary drainage shall be provided and maintained in order to prevent excessive surface run off and the erosion and possible sliding of materials onto adjacent properties or public roads Temporary drainage shall be directed into the existing local drainage system subject to suitable measures being taken to prevent silting or flooding from such existing drainage All hauling trucks and other construction plant leaving the borrow area or the area of placement on the site shall have wheels, wheel arches and other dirty sections washed before entering onto public roads Trucks used for hauling borrow materials shall not be overloaded Trucks used for hauling borrow materials shall be covered with canvas to prevent materials from being blown or falling off the truck The Contractor shall ensure that all operations related to the excavation and provision of materials from borrow pits comply with his approved Health and Safety plan, his approved Environmental Management plan and his approved Traffic Management plans The Contractor shall not obtain borrow material from locations other than the borrow areas approved by the Engineer for the Project IV MAIN EQUIPMENTS Main equipments include: Equipments Units Quantity Bulldozer ≥ 110 HP nos 03 Excavator 1,2m3 Nos 04 Vibrating Roller ≥16 ton nos 04 Steel Wheel Roller 10– 12 ton nos 04 Tired Roller nos 04 Dump Truck ≥10 tons nos 12 Laboratory Lab 01 PHUONG THANH TRANCONSIN ... Expressway Project Package A5 Civil Works Km 32+ 450 to Km 35+ 900 I GENERAL This method is a method of soft soil treatment, is replaced soft soil layer by suitable soil Common excavation will... TRANCONSIN GMS Ben Luc - Long Thanh Expressway Project Package A5 Civil Works Km 32+ 450 to Km 35+ 900 Backfilling On completion of the replacement soil, excavated areas shall be back-filled with approved... shall be as follows: III - Maximum size cm - Passing 4. 75 mm sieve 25% to 90% - Passing 0.0 75 mm sieve 0% to 10% - Liquid limit TCVN4197- 95 30% max BORROW MATERIAL All suitable materials provided