Engineering geological exploration geotechnical construction process is the most important part of the follow-up project has a crucial influence . The significance of the quality of the survey of the impact of the overall quality of geotechnical engineering has , it is self-evident. Before geotechnical engineering , good survey can not only help us to better understand first-hand information , the survey report also able to guarantee scientific and accurate follow-up set of construction plans to avoid major accidents .
Geotechnical Investigation Process

According to the relevant standard specifications , combined with daily practical work , geotechnical engineering investigation workflow is divided into five parts: preparation, site investigation, laboratory tests , finishing the compilation and post services. Preparation comprising: determining a reconnaissance mission and objectives , staffing and equipment , gather information, develop plans , and the preparation method selected outline ; site investigation stage is : geological mapping, prospecting fixed point , exploration operations , on-site catalog , field testing and sampling send mortem ; laboratory tests include : proofreading samples, calibration equipment , soil test and make a record sum up the results ; finishing assembly phase specific conduct : combing analysis, charting , preparation of reports , audit validation report submitted for review , feedback, revise , approve the parts and filing ; late services include: inspection of pile test tank, construction monitoring , advisory services and improve the summary , and finally finishing the archive .  

Geotechnical engineering investigation methods and techniques

Engineering geological mapping
Engineering geological mapping is the basis of geotechnical investigation work , usually in the early stages of the survey carried out . Engineering geological mapping site engineering geological conditions is to recognize the most economical and effective way of mapping the high quality work can be fairly accurately infer subsurface geological conditions , play an effective role in guiding other survey methods .

Exploration and sampling

Exploration work including geophysical , drilling and exploration methods such as pits , mainly used to investigate the underground geology , exploration work can also be used in situ sampling testing and monitoring .

In-situ testing and laboratory tests

General aid exploration works , is a major survey methods detailed investigation phase. Its main purpose is to provide analysis and evaluation of geotechnical problems required technical parameters, including indicators of soil physical properties , strength parameters , consolidation deformation parameters , permeability parameters and stress , strain and other parameters of the time .

On-site inspection and monitoring

Site inspection , including the construction phase on the results of the previous survey and geotechnical engineering verification and validation geotechnical construction supervision and quality control. Site monitoring role mainly includes construction and various aspects of load monitoring, geotechnical construction and operation of the reactor structures traits monitoring and environmental impact monitoring. Inspection and monitoring of the use of information obtained can counter some of the engineering and technical parameters obtained , and as a basis for timely amendment designed to make technical and economic optimization . This work was mainly carried out during the period of construction , but the project has special requirements , and some have a major impact on the project 's adverse geological phenomenon, should continue during the completion of the building operations .

Measures to improve the quality of geotechnical investigation
Establish a sound system of geotechnical investigation
Local governments should strictly monitor the market access for reconnaissance units , the establishment survey and technology department accreditation , certificate posts, so that personnel specialized geotechnical investigation to ensure the quality of geotechnical investigation . Geotechnical Investigation Unit periodic technical inspection personnel training survey , rigorous treatment unqualified personnel training , the only way to effectively improve http://www.ukthesis.org/management/ the technical level of reconnaissance personnel. Meanwhile will examine the geology of the surrounding area as a geotechnical investigation of the content , in combination with other projects to work together for the construction of the project services. Units should be made clear the importance of geotechnical investigation , and at any stage of the project construction should keep geotechnical survey work , as well as responding to emergencies encountered during construction .

Emphasis on team building field drilling

In geotechnical investigation works in the field of drilling is in dire need of responsibility and experience aspects of the survey sample he provided for the accuracy of the test data authenticity is important. With engineering exploration and geotechnical site investigation services inevitable separation techniques , some units geotechnical engineers the opportunity to live a little, and too much reliance on migrant workers as the main site investigation services team, but also more problems : insufficient amount of drilling, no earth is dug , the rules do standard penetration test anxiety , do not take the structure of undisturbed soil undisturbed , do not strictly regulate the water level in accordance with the determination , not water from the borehole , resulting in soil, water samples, rock testing distortion phenomenon . Therefore , enterprises in the formation of geotechnical engineering investigation over its own technology , we need to pay attention and have a good drilling tools and skilled team of co- workers, drilling , drilling teams appropriately increased costs, improve safety awareness contract with the drilling team to help long-term partner to improve the professional quality , enhance technical skills , experience, play creative spirit and achieve win-win situation .

Emphasis on the management of geotechnical laboratory

Geotechnical field testing is a reliable method to determine the physical and mechanical properties , for some physical soil can not field test , the mechanical index parameters , it is necessary to rely on indoor soil test is given , Geotechnical Investigation Department of Construction Enterprises in strict accordance with the standard reference unearthed the actual amount of drilling , geotechnical laboratory supporting the same level qualification . Eliminate individual survey units without expertise in the training of workers directly arrange reorientation soil test work , resulting in serious physical indicators of soil disorders ; prevent soil test instruments do not meet the requirements, test methods do not meet the regulatory requirements ; signature or eliminate liability Instrument Number fill insufficiency, such as indoor soil test , field construction records , the lack of responsibility CPT test records signature and date of test ; eliminate test instrument calibration is not required . To improve the efficiency of soil test room, a technology to improve the level of operating personnel and professional ethics , second, financially independent accounting , even with the imposition of economic stripped geotechnical investigation .

Geotechnical investigation report prepared by

Author of the report should have a wealth of geological features and engineering theory , the basic theory of geological knowledge , master the norms of order , has a profound experience , clear requirements and basic engineering design institute construction methods , but also to work on site geological record , and ensure the quality first-hand information . Correct evaluation of construction site conditions, ground conditions and special geotechnical problems and provide reasonable suggestions applicable for engineering design and construction. Must ensure that the quality of geotechnical engineering investigation report writing , so that the content is complete, data adequacy , focused his writing should follow certain procedures. In the report preparation process and outside the industry to ensure that accurate and reliable experimental data , should pay attention to the site catalog , in-situ testing and experimental data to check check, so that mutual agreement , reflection, writing reports and charts should be reasonable procedures relating to the preparation , order before and after care , smoothly conducted .

Geotechnical Investigation develop field construction supervision system

As a relatively complex and specialized construction projects , the particularity of geotechnical investigation work led directly to the difficulties of supervision . In this case, we must build supervision system in line with national standards , according to the survey unit mission requirements , the national " mandatory standards for construction " and local standards for the preparation of geotechnical engineering investigation outline, survey and survey clearly qualified supervision supervision units . For the data obtained during the survey to be carried out appropriate checks to ensure the accuracy and validity of the survey results in the true sense .

Improve survey targeted

Survey targeted to improve the quality for the protection of geological exploration has a very important practical significance to the loess reconnaissance sampling control, for example : collapsible loess inspection is one of the key issues at this stage loess area geotechnical investigation process . Here we are talking mainly refers collapsible loess area , groundwater in a short period of loess structural damage , leading to significant subsidence phenomenon. In this case, due to the increased weight of the loess itself , resulting in a very serious subsidence problems affecting the stability of the surface of the building is very obvious . Under normal circumstances, collapsible loess collapsible loess foundation .

Through the above analysis of the data and research can help us to further determine the collapsible coefficient , as a basis for the calculation of professionalism you can find the corresponding professional means to deal with. In the survey process Shanxi railway line in particular , is through the exploration and development of the loess , controlled by three hit circumference collapsible loess was not obvious . This data will determine our exploration sampling methods.

Conclusion

The importance of work -based geotechnical engineering investigation , we must strengthen the construction engineering survey geotechnical investigation project quality control, providing real engineering geological data , physical and mechanical properties of rock and other geological data related to the body , so as to ensure the whole project quality.