Abstract:The organization program of soil investigation which is different from domestic conventional project of marine bridge and tunnel have been adopted in island-tunnel project of HZMB. The geotechnical investigation organization was set up to connect design during investigation. Domestic and foreign design and consulting companies supervised and directed the soil investigation together to make sure that the investigation results were satisfied by designer. International standards were followed, large-scale geotechnical equipments of advanced level were used (such as offshore hydraulic driven jackup, separate hydraulic driven drilling rig, seabed CPTU rig), undisturbed samples have been minimized the disturbance, targeted laboratory tests combining the designing requirements were carried out under international levels, the three-dimensional geological model have been adopted to process geotechnical data. Based on the above fact, the geotechnical results of island-tunnel soil investigation are better than the conventional soil investigation and approved during construction. After the summary of the organization and implementation of refined soil investigation and comparison with conventional investigation, it is recommended that our experiences of refined soil investigation can be used in domestic large-scale project in the future, also it is useful to promote the refined soil investigation to wildly develop in our country.

Abstract:Due to the little field for the construction of coastal port construction at present, there is a need to construct large infrastructures such as harbor, bridge, tunnel and wind turbine along the coast with a worse natural condition. As a result, the bad sea conditions such as heavy wave, rapid current, deep water and huge wind are encountered for the coastal investigation work. On the other hand, the comprehensive investigation technologies adapting the high standards and strict requirements are required for the large infrastructures to find out the complex geological conditions. The traditional and single overwater investigation technologies are hard to satisfy the requirements of the large project’s construction, and the new investigation technologies are necessitated to be sought for. Taking the investigation technology of CCCC-FHDI Engineering Co., Ltd. as an example, this paper reviews the process of the coastal investigation technology and prospects to enhance the international competitiveness, which will provide reference for the promotion of the domestic coastal investigation technology and participate in the international competition.

Abstract:Based on the international code, this paper carries out the fine soil investigation work for Hong Kong-Zhuhai-Macau bridge island-tunnel projec to get the soil characteristics as accurately as possible due to the excellent design requirements. According to the successful experience of the fine soil investigation work of the project, the paper discusses the management for the highly qualified personnel staff, process control and full range of coordinating the fine soil investigation mode to satisfy the requirements of the schedule and quality for the fine soil investigation, which provides reference for similar projects.

Abstract:Based on the successful application of seabed CPTU equipment in Hong Kong-Zhuhai-Macau bridge island-tunnel project, this paper analyzes the advantages of seabed CPTU system in offshore investigation, and provides some recommendations for the popularization of it in future offshore projects.

Abstract:Cone penetration test with pore pressure measurement is a rapid and reliable in-situ test method, which has been applied widely in the world. Meanwhile, according to the analysis on CPTU and other in-situ tests such as SPT, VST and shear wave velocity test, many correlations can be developed.

Abstract:According to the correlation analysis between CPTU data and laboratory testing data in the soil investigation of Hong Kong-Zhuhai-Macau bridge, some good correlations between CPTU data and fine content, unit weight, moisture content, void ratio, plasticity index and liquidity index are developed. Based on these correlations, a new method to evaluate soil physical parameters through CPTU test is provided.

Abstract:Cone penetration test with pore pressure measurement (CPTU) is a rapid in-situ test method. Most interpretation methods are based on empirical correlations through statistical analysis at present. Based on the wide application of CPTU data interpretation on soil classification, undrained shear strength of cohesive soil, friction angle of sandy soil and subgrade uniformity to the soil investigation of Hong Kong-Zhuhai-Macau bridge, some conclusions are drawn.

Abstract:This paper elaborates main methods for pile capacity assessment based on CPTU, and analyzes the applicability of them. Combining with the regional soil layer’s engineering property, this paper analyzes the corrected CPTU data and two pile load testing results, and proposes a new regional pile capacity prediction method, based on CPTU, which may serve as reference for the engineering design. Due to the use of the corrected CPTU data, this method can predict more accurately the pile capacity. Moreover, it also has good engineering practicality and operability.

Abstract:Saturated soft clay is most commonly encountered in the construction of waterway engineering, and vane shear test has been widely used for the determination of shear strength of saturated soft clay. Combining with the geotechnical investigation of island and tunnel project of Hong Kong-Zhuhai-Macao bridge, this paper discusses the technology improvement and application of results analysis for electrical measuring vane shear test.

Abstract:According to the standard and manual in the American and European countries, corrected SPT N60 is used to obtain the parameter for soil and (N1)60 is used to obtain the parameters and determine the liquefaction for sand. According to the port project in Venezuela, the SPT method according to ASTM and the corrected SPT method are introduced. The factors influencing the SPT correction are also analyzed. N60 is mainly influenced by energy correction factor CE, and when the soil locates more than 10 m, the N60 is usually more than the original value Nm. (N1)60 is corrected upon overburden factor CN based on N60, for the top layer sand, (N1)60 is usually more than the original value Nm and the lower layer (N1)60 is usually less than the original value Nm. Compared by several methods, the undrained shear strength Cu for a certain over-consolidated clay , with SPT values between 15 and 50 blows and with little coarse grains, can be derived by N60 , which is confirmed to be reliable.

Abstract:Hong Kong-Zhuhai-Macao bridge island tunnel project needs to meet the investigation standards of Hong Kong, Macau and Chinese Mainland. Thus it’s necessary to set up an engineering geological unit layer to provide the criterion for geotechnical engineering evaluation. Based on the feasibility stage investigation report, preliminary investigation report, detailed investigation and supplement investigation report, and according to the geological origin and times, soil information rocks and physical & mechanical properties, we unify different specifications divide the engineering geological unit layer in keeping with investigation standards to provide a basis for the Pearl river delta estuaries.

Abstract:The foundation settlement is designed to focus on deformation characteristics of soft clay under different loads over time. According to the coefficient of consolidation and preconsolidation pressure under the oedometer test, we analyze the variation characteristics of coefficient of consolidation before and after normally consolidated soft clay. Relevant suggestions are put forward to serve as reference for the research on Zhujiang delta continent soft clay’s mechanical characteristics.

Abstract:The evaluation of liquefaction resistance for HZM bridge tunnel engineering is to provide the basic data for the bridge design. The criteria for evaluation of liquefaction resistance which accord with British Standard include preliminary criteria and detailed criteria. Criteria based on SPT, CPTU, wave velocity test are all used in detailed criteria. The results of a comprehensive analysis of liquefaction by different methods, determine the final results of evaluation of liquefaction resistance of sand, and propose treatment measures. We discover the laws and differences with the GB standard of the evaluation in the area of Pearl river delta on the sea and provide experience.

Abstract:In order to establish the correlation between physical properties and mechanical properties, we obtain the ratio of undrained shear strength and effective pressure Su/p′0 under the anisotropic consolidation triaxial shear test, analyze the correlation between Su/p′0 and liquidity index/plasticity index/liquid limit, and establish the relative formula on normally consolidated soft soil Su/p′0 and consistency index at the estuary of the Pearl river delta, and assess the normalized behavior.

Abstract:This paper analyzes the hydro-geologic characteristics of HZM bridge tunnel according to the hydrological and meteorological data, chemical analysis of water, pumping test, CPTU, topography, stratigraphy, as well as soil’s physical and mechanical properties of the HZM Bridge tunnel area. The result shows that the field of surface water is sea water, the loose stratum pore water is weak-pressure water, and there is a direct hydraulic connection between bedrock fissure water and loose stratum pore water. The region is typical delta estuary zone and its engineering hydrogeological characteristics are unique, so it can supply experience for other similar delta estuary zone engineering.

Abstract:In order to indentify the variation characteristics of the coefficient of secondary consolidation of soft clay at the estuary of the Pearl river delta, and provide a basis on the precise parameters of the settlement design for ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? the tunnel project of? Hong Kong-Zhuhai-Macao Bridge island? , we carry out a classification test and consolidation test on the undisturbed samples of grade I, so as to obtain the relative physical and settlement parameters, analyze the characteristics of the coefficient of secondary consolidation with load changes, and study the correlation between the coefficient of secondary consolidation, preconsolidation pressure, compression index , water content and plasticity index. The results show that the coefficient of secondary consolidation increases linearly with the increase of water content, plasticity index; the ratio of the coefficient of secondary consolidation and compression index is not a constant in the normal consolidation; the coefficient of secondary consolidation is small and increases with the load growth before loading is less than the preconsolidation pressure, it is from large to small with the load growth after loading is more than the preconsolidation pressure. This research ascertains the variation characteristics of the coefficient of secondary consolidation, founds the correlation of coefficient of secondary consolidation and related physical and mechanical indexes, and forms a regional guidance for the deformation calculation of soft clay at Pearl River Delta.

Abstract:The geotechnical engineering features of the project of Colombo south harbor container terminal are analyzed, and especially the characteristics of granitic gneiss as the bearing stratum are analyzed. Some issues are discussed such as the selection of physical and mechanical parameters, the calculation of the compression and deformation, and the softening and disintegrating when soils meet water, and so on. It is hoped to provide the reference and guidance for the future work.

Abstract:This article describes the application of geologic analysis and combinative economic analysis to select the optimal site for a LNG plant in Iran. Collecting the geologic data of the intended site A & B, combined with field geological survey, we extract the geologic features of the site to be selected, and know that the sand, calcareous cementation and submerged reef are key influential factors for the flat land site, foundation treatment, pile foundation and pile driving process, channel excavation, construction of the main terminal, power plant and liquefaction plant base, and are the core influencing the engineering cost. The conclusion is drawn that site B is the best one .

Abstract:Tunnel foundation for island-tunel project of HZMB using a variety of foundation forms, including PHC rigid pile composite foundation, high pressure jet grouting pile composite foundation, sand compaction pile composite foundation and natural foundation. In this paper, the composite foundation and natural foundation settlement calculation methods and parameters selected is analyzed with Code for design of building foundation, Technical code for ground treatment of building and Technical standards and commentaries for port and harbor facilities in Japan, which indicates that the sand compaction pile composite foundation settlement calculation should refer to Technical standards and commentaries for port and harbor facilities in Japan, PHC rigid pile composite foundation settlement calculation should follow the Code for design of building foundation GB50007—2012, high-pressure jet pile composite foundation settlement calculation should comply with Technical code for ground treatment of building provisions of cement mixing pile, natural foundation settlement should consider stress history e - lgp settlement calculation method and secondary consolidation coefficient for settlement calculation should match the actual stress test. This article outlines settlement caculation methods and parameters selection principle of different foundation treatment methods for the HZMB island tunnel works, to provide reference for similar projects in settlement calculations.

Abstract:According to the comparison of different shear strength test results gained from fine and common soil investigation in west artificial island of Hong Kong-Zhuhai-Macau bridge, we analyze the difference of shear strength caused by sampling methods, and analyze the correlation and otherness of different shear strengths, which provides a reference for the shear strength of cohesive soil in future research.

Abstract:It’s unreasonable that the compression modulus is considered as an almost constant at present during the compression estimation and deformation calculation of soils. Combining the geotechnical test results in project of Hong Kong-Zhuhai-Macao bridge, we analyze the evolution law of compression modulus under loads’ changing, and discuss the evolution range of compression modulus under different loads. It may serve as reference for deformation calculation parameters of soils.

Abstract:This paper summarizes differences of liquid limit tests between Chinese and other countries’ standards or codes including GB/T 50123, JTG E40 and BS1377. Combining the Hong Kong-Zhuhai-Macao bridge project, some useful experiential relations are obtained after statistics and analysis of the results of liquid limit tests under different standards or codes, which can provide guidances for the future work.

Abstract:This paper analyzes the detection method for seabed obstacles from the detection principle, basic situation and application effect, etc., discusses the advantages, disadvantages and adaptable condition of the methods, and summarizes the current situation and development trend of the detection technology.

Abstract:Based on the HZM bridge engineering and other ocean engineering project, we analyze the effect of geophysical exploration on the ocean engineering, including geological survey, obstacles survey, dredging quantity calculation, etc. We also discuss the defects and differences of geophysical exploration.

Abstract:The paper introduces the characteristics of cross-hole wave velocity testing and sedimentary strata and cross-hole wave velocity testing is applied to the sedimentary strata. For there are several strata inter-beded with soft stratum in the sedimentary strata area, reasonable parameters, drilling, deviation measuring, the space of boreholes and locations of testing points are designed to conduct the wave velocity test. The result shows that the cross-hole wave velocity testing can be applied to the inter-beded stratum and thin stratum of sedimentary strata and obtain reliable result.

Abstract:According to the relevant GPS codes of our country, the method of loop closure checking is used to calculate 3D coordinate components separately. While in Trimble Business Center (TBC) software, the method of loop closure checking is to calculate the horizontal and vertical components separately. How to calculate the loop closure with 3D coordinate component mode and how to distinguish simultaneous loop and independent loop is an important issue for implementing the required Code under TBC software. The paper is to discuss how to design the GPS field data quality program to solve the problem.

Abstract:Combining with some projects implemented in less developed countries, this paper summarizes difficulties and problems in the coordinate system and horizontal control survey implemented in other countries, proposes the method for establishing the horizontal control network and international technological advancement, and probes into relevant technology, aiming at serving as reference for the engineering design and survey.

Abstract:GPS precise point positioning is a positioning method which using a single double frequency receiver to observe and calculate very precise positions up to several millimeter level based on the international terrestrial frame (ITRF). It is very useful due to its easy fieldwork and simple data processing. The paper introduces the principle of this method and its high precision. Combining with some projects finished by our company in recent years, this paper discusses the application to similar projects.