METHOD STATEMENT r1

ADCOM Consultants FLoor, No 82, 116 lane, Nhan Hoa Street, Nhan Chinh, Thanh Xuan distric, HN; Tel: +84 2215 8835/2215 8813; Fax: +84 6251 0843; Email: contact@adcomconsult.vn; Website: www.Adcomconsult.vn METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADDRES: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE Ha Noi, 2018 METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE PROJECT MANAGEMENT UNIT THANG LONG SUPERVISOR THE CONTRACTOR MONITORING CONTRACTOR METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE MỤC LỤC I GENERAL information 1.1 GENERAL i Project information: .4 ii Overview of the purpose of the monitoring 1.2 Scope of work a) Scope of work .5 b) Frequency of measurements: 1.3 Basis for implementation II METHODOLOGY Monitoring of settlement by surface settlement plates: a) Purposes: .6 b) Equipments c) Methods of installation: d) Benchmarks: e) Accurate measurement: f) Monitoring cycle: g) Monitoring methods: Monitoring of Horizontal and vertical movements by wooden stake: 1.1 Purposes: .8 1.2 Thiết bị 1.3 Methods of installion: 1.4 Monitoring cyclo: Monitoring of Pore water pressure: 1.5 Purposes 1.6 Equipment of monitoring: 10 1.7 Equipment Installation 10 1.8 Installation sensor depth: 12 - 02 sensors were installed in one drilled location (high level H1, H2) 12 1.9 Monitoring cyclo: 12 Monitoring of horizontal displacement by Inclinometer 12 1.10 Purposes 12 1.11 Equipment, materials and tools: 13 METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE 1.12 Process of installation 14 1.13 Measurement procedure 15 1.15 Data processing .16 Monitoring of Ground water Level by Observation Well 19 1.16 Purposes 19 1.17 Measurement equipment 19 1.18 Installation of observation well .19 1.19 Monitoring 22 Report the results 22 1.20 Horizontal transverse monitoring: 22 1.21 Subsidence monitoring: 23 1.22 Groundwater well monitoring: 23 III SAFETY .24 Safety purpose 24 1.1 Occupational safety and health in the course of implementation 24 1.2 Minimum labor protection .24 1.3 Safety in construction 25 IV APPENDIX 27 Team work 27 V DRAWING OF MONITORING LAYOUT 28 METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE I GENERAL INFORMATION 1.1GENERAL i Project information: Project: THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) PMU: PROJECT MANAGEMENT UNIT THANG LONG The contractor: Long Bien bridge JSC Observation Contractor: ADCOM Civil Engineering Consultancy and Investment JSC ii Overview of the purpose of the monitoring - Monitoring of road subsidence, monitoring of open water pressure, static water level and observing the horizontal movement of the ground - Calculate the settlement rate and degree of consolidation during the execution and when works is taken into exploitation Base on the settlement monitoring data, the Engineer consultant and Contractor can: + Evaluate the efficiency of soft soil treatment + Adjust the backfill schedule considering the settlement rate and the total settlement of the foundation soil + Forecasts of possible incidents during the construction process, outline preventive measures and how to overcome if occur Contents of monitoring work include: (1) Surface settlement Plates(SSP) (2) Lateral displacement observing stake (WP) (3) Electric Piezometer (EP) (4) Observation Well (WO) (5) Measure deep-horizontal movement by Inclinometer 1.2Scope of work METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE a) Scope of work No Content of perform Unit Quantity P 78 Surface settlement Plalates Lateral displacement observing stake pipe 156 Observation well in sand cushion Observation well Measure deep – horizontal movement note note 04 04 note 08 note 08 by Inclinometer Electric Piezometer Remark Detailed monitoring equipment according to the enclosures b) Frequency of measurements: After installed equipment monitoring, measurement and data recording the frrst The time taken to get observation data from the beginning of road foundation Frequency of measurements: - It is necessary to carry out daily measurements / inspections of the surface subsidence or monitoring wells before and after each loading (in layers of embankment or embankment) during the embankment - Check the piezometer, measuring table and observation well 01 times / day in the first week after installation - Frequency of measurements of kind: Monitoring equipment Surface settlement Plates After embankment During the road embankment The first month 2nd month to the end of the period After unloading time / day time / week time / week time / Month time / day time / week time / week time / Month Lateral displacement observing stake METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE Inclinometer time / day time / week time / week time / Month Piezometer time / day time / week time / week time / Month Observation Well time / day time / week time / week time / Month Remark: - During continuous rainfall, the water level is monitored daily and as directed by the Consultan - Abnormal data should be reported to the Consultant for possible causes 1.3Basis for implementation - - Requirement documents of investor; - Construction design document; - TCVN 4054-2005: Highway; - TCVN 8869 - 2011: Method for measurements of pore pressures in soil ; - TCVN 9398 - 2012: Survey in contruction; - TCVN 9360 – 2012: The process of determining the settlement of civil and industrial with high geometric measurements - And other related documents .II METHODOLOGY Monitoring of settlement by surface settlement plates: a) Purposes: Settlement monitoring for Surface settlement Plates is to calculate the settlement rate and degree of consolidation during the execution and when works is taken into exploitation Base on the settlement monitoring data, the Engineer consultant and Contractor can: - Adjust the backfill schedule considering the settlement rate and the total settlement of the foundation soil - Timely detect and treat the slope instability of the embankment - Calculate the expected fmal settlement of the embankment - Determine the time to remove the surcharge for construction of road surface structure and the other works METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE - Calculate volume of settlement compensate during construction; b) Equipments Steel plate 500x500x08mm, settlement bar 1.0 m welding steel plate size D40, outside protected with PVC pipe D110, extended by the glued connector Details of attachment Settlement monitoring equipment is Nikon NIKONAC -2S or other machines with the same accuracy - Magnified lens 30x times - Field of vision 1o30‘ - Accuracy +_10‘/2mm - Shortest distance : 0.4m c) Methods of installation: Surface settlement plates Installed in locations according to design drawings and as per technical specifications Procedures and methods of installation Surface settlement plate as follows : - Location coordinates and elevation of installation fact must be checked at the site - Flatten the surface put surface settlement plate - Install surface settlement plate right position - Measureandrecord thecoordinatesandelevationinstalled Conecting the sections of steel pipes D40 and PVC D110 protection pipes to the high of embankment Determine the subsidence of bench following the high of top steel pipe The composition of bench and installation locations are showed on the attached drawing d) Benchmarks: Use the available landmark at the construction site as benchmark observation site METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE e) Accurate measurement: Benchmarks are difined and adjusted in National grade of III accuracy Closing error fh = n , here n : servey station Error for station 1mm/1station f) Monitoring cycle: + During the road embankment: time / day + After embankment: The first month time / week 2nd month to the end of the period time / week + After unloading: time / Month g) Monitoring methods: + The monitoring of settlement measured by level precision matching of standards and benchmarks + The displacement of the roadbed was determined by the high differential of the Steel plate at the time of measuring comparing to the time of installation Monitoring of Horizontal and vertical movements by wooden stake: 1.1 Purposes: Horizontal displacement monitoring on surface surrounding the road embankment is to observe the displacement of the alignment stake The alignment stake is piles into the nature soil surface along the embankment road 1.2 Thiết bị The alignment stake is made of wood with the dimension D Ocm, length of 70cm, 120cm deep install into the soil At the top of wood bar is staked nail (Scm long) which is the foundation for locating the pile The wooden stakes must straight, not warpmg Detail in attached appendix below In oder to determine the incline using electronic tachometer good sensitive Trimble M5 or other equipments with sensitive equivalence No Specification of Trimble Accuracy value METHOD STATEMENT FOR SOFT SOIL MONITORING THINH LONG BRIDGE CONSTRUCTION PROJECT (VNM-48) ADD: COMMUNES HAI CHAU, HAI HAU DISTRICT & COMMUNES NGHIA BINH, NGHIA HUNG DISTRICT, NAM DINH PROVINCE Horizon angle accuracy Verticle angle accuracy Auto balance sensitive Longest distance determination a, Use the mirror b, Determinating distance by Laser (none mirror) c, Use the Leica mirror Determinating length accuracy Determination of time ( Standard deternination programe) ± 2” ± 2” 1"