Môc lôc VRAMP –CONTRACT PACKAGE RAP/CP9– MAINTENANCE OF NH6 FROM KM138÷KM158 IN HOA BINH AND SON LA EXCAVATION TABLE OF CONTENTS I COMMON EXCAVATION II CONSERVATION OF TOPSOIL III USE OF EXCAVATED MAT[.]
VRAMP –CONTRACT PACKAGE:RAP/CP9– MAINTENANCE OF NH6 FROM KM138÷KM158 IN HOA BINH AND SON LA EXCAVATION 1/ TRANCONSIN PHUONG THANH VRAMP –CONTRACT PACKAGE:RAP/CP9– MAINTENANCE OF NH6 FROM KM138÷KM158 IN HOA BINH AND SON LA TABLE OF CONTENTS I COMMON EXCAVATION II CONSERVATION OF TOPSOIL III USE OF EXCAVATED MATERIAL IV EXISTING PAVEMENT EXCAVATION V SKIN PATCH VI BASE PATCH VII DEEP PATCH VIII DIMENSIONAL TOLERANCES 2/ TRANCONSIN PHUONG THANH VRAMP –CONTRACT PACKAGE:RAP/CP9– MAINTENANCE OF NH6 FROM KM138÷KM158 IN HOA BINH AND SON LA COMMON EXCAVATION I Common excavation A pre-construction survey, which refers to the datum plane used in the approved plan, shall be undertaken by the Contractor under the control of the Engineer to serve as a basis for the computation of the actual volume of the excavated materials All excavations shall be finished to reasonably smooth and uniform surfaces No materials shall be wasted without authory of the Engineer Prior to excavation, all necessary clearing and grubbing in that area shall have been performed During the excavation, the attention is paid to keep excavated ground always dry, well drained, take measures to prevent water flow into the bottom of the excavated ground (diversion of water flow and clearing drainage) Excavator used in combination with labors to level and make slope of the embankment, size of each level shall be followed as design, ensuring good contact between the new and existing embankment All excavated materials will be transported and hauled away by trucks to dumping area or landfill areas, which are permitted by the Employer and the Engineer, the re-used material must be gathered at the right place, piled, creating slope for good drainage, and does not affect the surrounding environment After excavating to the bottom elevation of the new roadway embankment, sending request for inspection to the Engineer for his inspection and acceptance of the work, then move to the next work items II Conservation of Topsoil In accordance with the provisions of Specification section 2.1 “Clearance and Grubbing”, suitable topsoil encountered in excavation and on areas where embankment is to be placed shall be removed to such extent and to such depth as the Engineer may direct The removed topsoil shall be transported and deposited in storage piles at locations approved by the Engineer The topsoil shall be completely removed to the required depth from any designated area prior to the beginning of regular excavation or embankment work in the area and shall be kept separate from other excavated materials for later use III Use of Excavated Material 3/ TRANCONSIN PHUONG THANH VRAMP –CONTRACT PACKAGE:RAP/CP9– MAINTENANCE OF NH6 FROM KM138÷KM158 IN HOA BINH AND SON LA All suitable material removed from the excavation shall be used in the formation of the Cohesive Slope Material, capping layer, embankment, subgrade, shoulders, slopes, bedding, surcharge and backfill for structures, and for other purposes shown on the Drawings or as directed by the Engineer Any material surplus to these requirements, or any material declared in writing by the Engineer to be unsuitable, shall be disposed of by the Contractor outside the right-of-way or as directed by the Engineer IV Existing pavement excavation Before excavating and repairing pavement, the Contractor shall submit the Engineer the proposed working schedule, list of equipment and the explanation of expected construction methods The Contractor shall inform the Engineer to witness the measurement of defective area before excavating and repairing any position Any change in geometric demensions and types of damage in comparison with the approved design shall be recorded in the minutes and measured by the Contractor and the Supervision Consultant in order to determine the geometric dimensions and types of damage in need of repairing which is the basis for acceptance and payment later Removed and excavated material amount before measurement and without the Supervision Consultant’s acceptance will not be paid Excavation shall be implemented to the design level specified in the drawings, including cutting asphalt concrete, benching for each layer of material Excavation is not allowed to continue until the Engineer observes the pit and makes sure that at the excavated level, the structure is not defective and meets design requirements If the material layer at the excavation bottom of design level is not appropriate, the excavation shall be done to the full depth of defective material layer for treatment guided by the Engineer Backfilling shall follow the drawing or Engineer‘ instruction Backfilling material layers and the existing one shall be rolled to guarantee the density and adhesiveness of the new and old materials V Skin patch Skin patches are employed to repair surface failures in the existing asphalt pavement Skin patches shall be provied as indicated on the Drawings at locations designated in the field by the Consultant Surface Preparation: Saw cut down vertically to the full depth of the defective area of the pavement surface The saw cuts shall be made by transverse and longitudinal cuts and form a neat rectangle The damage with the width