Supervision of water conservancy project construction survey?

Supervision of water conservancy project construction survey is very important. Only by doing a good job of measurement and having data as a reference can it be used for professional knowledge and preparation in combination with the actual situation. Zhong Da Consulting will introduce you to the survey supervision of water conservancy project construction.

1 Introduction

Surveying is a relatively independent applied work in geodesy, which is roughly divided into geodesy, engineering surveying, aerial photogrammetry, map printing and other majors. Engineering survey activities can be divided into three categories: ① mapping the topography of the planning area to the topographic map on the map in order to provide designers with the route selection and site selection of the project; (2) The design drawings will be realized in the ground construction lofting, and its function is to transfer the engineering drawings designed on the map to the ground; (3) Monitoring the deformation of ground objects or buildings to provide safety information for the construction process or buildings. These three activities all involve GPS survey, triangulation or traverse survey, leveling, precise ranging, lofting and positioning, as well as complex professional surveying techniques, such as surveying leveling. Engineering supervision is an act that the owner authorizes professional supervision institutions to provide escrow services for the engineering construction process. Surveying supervision is an activity in which the surveying professional engineer with the qualification of supervising engineer in the supervision organization uses his professional knowledge to supervise the timeliness, authenticity, accuracy and completeness of the contractor's surveying setting-out, surveying, surveying acceptance and submission of information during the construction process. Obviously, survey supervision has the intersection or comprehensiveness of survey technology and construction supervision. Without qualified survey supervision, it is difficult to implement real survey supervision control for contractors, and its importance is self-evident. Paper test. At present, there are few articles that systematically discuss investigation and supervision. The author has long worked in the front line of professional surveying and mapping and engineering supervision, and has a deep understanding. It is hoped that through a comprehensive and systematic discussion of related issues, the regulatory agencies will enhance their understanding of investigation and supervision.

2 survey and supervision qualification

Surveying supervision is a very important professional engineer in the project supervision organization, and its working characteristics require employees not only to have supervision knowledge and ability, but also to master surveying and mapping professional knowledge extensively and accurately. According to the experience of hydropower project supervision in North China, the selection of survey supervision personnel can be investigated from the following aspects: ① having the qualifications of survey engineer and supervision engineer; ② Have good professional ethics and personal qualities. If you have a sense of contract, strong principle, advanced thinking, earnest and meticulous, active in work, seeking truth from facts, fair and honest, good at communication, decisive in decision-making, and have the overall concept, you can bear hardships; ③ Have extensive professional theory and practical experience, and show good professional quality. Should be proficient in control survey, digital mapping, engineering survey, deformation observation, survey adjustment and engineering survey, but also should have hydraulic knowledge and map reading ability, skilled use of computers and office, drawing, adjustment, measurement software. In fact, freelancers with the above conditions are rare in society. Even large Grade A professional survey teams are often unfamiliar with engineering and supervision business. At this time, we should focus on professional ability, and other aspects can be improved in our work.

3 The main responsibilities of survey supervision

The responsibilities of survey supervision can be summarized as follows: ① Under the authorization and leadership of the chief supervision engineer, independently carry out survey supervision work and accept the business guidance of the corresponding departments of the employer; (2) Establish a perfect working mechanism and system, and supervise the survey work in the construction process of the blocks under its jurisdiction in a whole process and system; (3) Cooperate with the on-site supervision engineer and other functional departments' survey requirements, and strive to fully complete the supervision contract.

4 the important role of measurement supervision

The construction process is the process of implementing drawings and realizing investment. The correctness of survey and setting-out before construction has a fundamental impact on project quality control, and the accuracy of survey has a significant impact on investment control, as follows:

4. 1 quality control

The function of measurement is to determine the spatial position of ground objects, and link the data of each part correctly with the same accuracy by measuring the macro skeleton of control network. The function of quality control is construction lofting. Without the correct guarantee of surveying and setting out, even the best design concept is only a "model" and cannot be realized correctly on the ground. No matter how fast the excavation is, the wrong hole will be filled, and the bid will be invalid. No matter how firm the concrete is, it will be blown up if it is not in the right position! That is, any mistake in construction lofting will cause fundamental losses, so the measurement work is the first and the indicator light to ensure correct construction. Checking and ensuring the correctness of survey setting-out is one of the most important tasks of survey supervision. In addition, in the acceptance of foundation surface and completion survey, it is necessary for the survey supervisor to identify and draw conclusions through reliable survey results, which plays an irreplaceable role.

4.2 Investment control

Open-cut excavation in water conservancy and traffic engineering is often a big item that cannot be simply calculated by formula, and its accurate measurement is a major aspect of investment control. In the past, both parties to the contract often had no confidence through vehicle inspection, pile evaluation, or simply using the numerical measurement in the bill of quantities when bidding. Because there is no scientific calculation method, when there is a dispute between the two parties to the contract, they can't come up with convincing data to overthrow the other party. The measurement principle stipulated in the general contract terms is that the bill of quantities is only an estimated quantity, and the settlement quantity should be the actual quantity that has been completed and meets the measurement requirements, which usually needs to be obtained through joint measurement. The survey results obtained from the joint survey of the original topography before construction not only overcome the measurement errors in the bill of quantities caused by the old original topographic map, small scale and few sections, but also gain the recognition of both parties to the contract, thus avoiding disputes. The survey supervisor has a comprehensive and detailed knowledge of the design drawings, and has the ability of computer drawing processing and calculation, so he can monitor and audit the measurement of quantities in all irregular areas such as earthwork excavation, backfill and shotcrete, so as to make the measurement results accurate and reliable.

Measurement data is also an important basis for handling claims. It contains the spatial three-dimensional shape of the measured object, the attributes of the mutual position relationship and the time series reflecting the construction process, so it contains a wide range of basic information about the engineering and construction process, which plays an irreplaceable and indisputable qualitative and quantitative role in dealing with the ownership and size of the contract responsibility. For example, slope survey data can reflect whether the contractor excavates according to the design slope and whether the supervisor's relevant flood control instructions are implemented in time, which is an important basis for landslide treatment. Deformation observation data can reflect whether it has completed its monitoring obligation and timely rescue support, which is helpful to distinguish geological reasons from contract responsibilities. An excellent survey supervisor can sensitively discover, collect, control and accurately process survey information, so that the supervisor will no longer rely on estimation, feeling, impression, memory and slapping his head, and handle claims reasonably, accurately, scientifically and fairly. The employer and the contractor are very clear and convinced, willing to accept, but also have to accept.

North China Hydropower Supervision Center has selected excellent survey engineers as survey supervisors in several project departments, such as Wanjiazhai Yellow River Diversion Project in Shanxi, Dongshen Water Supply Reconstruction Project in Guangdong, Daban Tunnel in Yili, Xinjiang, and Middle Route Project of South-to-North Water Transfer Project, which has played a very important role and become the right-hand man of the chief supervision engineer. Most of the accumulated measurement data and documents account for more than one third of all supervision data, which brings great convenience to the project supervision department to correctly handle measurement and claim. For example, the measurement of the contractor's earthwork excavation and backfilling, slope shotcrete and other irregular quantities depends on the measurement supervision, and the joint measurement results are recognized by combining the opinions of the site supervision, contract provisions, design changes and quality evaluation. There has never been a dispute. It also relies on survey data to reject many unreasonable claims of contractors, convincing them, fully demonstrating the important role of survey supervision in investment control, and also establishing the image of scientific supervision of project supervision departments.

5 working principles of survey supervision

According to the importance and particularity of survey supervision, the working principles formulated by North China Hydropower Engineering Supervision Center are as follows: ① Strictly abide by the contract provisions and national surveying and mapping norms, deal with non-principled technical problems flexibly, and speed up the project progress; (2) Be fair and independent, treat all blocks equally, be impartial to the employer and the contractor, actively safeguard the rights and interests of the employer, and do not deceive and suppress the contractor to safeguard their legitimate interests; Adhere to principles, be not soft-hearted in quality problems, be honest and self-disciplined, not seek personal gain, and refuse to seduce and intimidate; 4 convince people with reason, respect people with courtesy, help people with skill, and be sincere and touching; Actively communicate with all parties, enhance understanding, and strive for the understanding and cooperation of all parties in the investigation and supervision; (5) Abide by professional ethics, be loyal to original records and data, speak by data, have a basis for words and deeds, and don't talk nonsense beyond the scope of duties; 6. Honest and trustworthy, duty-bound, project first. Hard work, active supervision, attention to pre-control, quick response, open-minded learning, good advice; ⑦ When giving instructions and replying, you should be considerate, clear in conception, clear in expression, accurate in wording, operational, and resolute in urging implementation; ⑧ Actively cooperate with other supervisors and promptly remind other management omissions found.

These working principles standardize the behavior of measurement supervision departments of various projects and become their code of conduct.

6. Work basis of survey supervision

Water conservancy projects are different, but survey supervision should generally work in accordance with the following contract terms and technical specifications: ① Effective contract documents (tender documents, bidding documents, agreements, supplementary agreements, priced bill of quantities, etc. ); (2) Construction drawings and design modification notice signed by the supervision department; (3) The approved contractor's construction measure plan and progress plan; (4) Instructions and decisions of the Employer forwarded by the Supervision Department, and notices of new projects and changed projects approved by the Supervision Department; ⑤ Relevant supervision notices and on-site instructions issued by the supervision department, as well as meeting minutes formed by regular supervision meetings and special supervision meetings; ⑥ Current national and water conservancy surveying and mapping specifications commonly used in construction: national triangulation specification, third-and fourth-class traverse survey specification, national first-and second-class leveling specification, national third-and fourth-class leveling specification, water conservancy and hydropower survey specification (planning and design stage), water conservancy and hydropower construction survey specification, engineering survey specification and GPS survey specification; ⑦ Engineering quality evaluation standards issued by the Ministry of Water Resources and quality control standards agreed in the contract; ⑧ Description of measuring instruments and software.

The supervision department of North China Hydropower Engineering Supervision Center carried out survey supervision work in strict accordance with the above basis. From the beginning, the contractor felt that the requirements were too strict to gradually adapt, understand and cooperate, which benefited from the standardization of survey work, and the high-quality survey data also won wide acclaim from employers.

7 Control means of survey supervision

In view of the current situation that the contractor's measurement power is generally weak, the supervision experience of North China Hydropower Supervision Center is that it is necessary to do a good job of pre-control, ensure the timely, accurate and complete collection of measurement data, and lay a solid foundation for reviewing the measurement results afterwards and drawing reliable conclusions.

Control beforehand is twice the result with half the effort. Contractors often rush into the site and immediately want to dig. At this stage, the survey work is particularly urgent and arduous, including the qualification of surveyors and work inspection system, instrument verification and inspection, control network handover and review, construction control network encryption, original topographic survey, excavation line inspection and so on. If not pre-controlled, it will delay a lot of time and affect the construction progress. If the instrument fails to verify the measurement results, it will be invalid. If the control network fails to verify, the director will not be able to issue a commencement order! Therefore, after the contractor enters the site and is authorized by the director, the survey supervisor must immediately contact the contractor's survey team and intensively carry out detailed pre-control work, including establishing working relationship, negotiating work system, understanding the situation of personnel and instruments, and urging to solve related problems. An excellent surveying supervisor can often quickly establish the trust, respect and influence of personality and technology among contractors. At the same time, it is necessary to participate in the preparation of supervision scheme and inform the contractor of the implementation details and data format of survey supervision, which is conducive to the smooth cooperation of work and the neatness and unity of data.

There are many ways to control things. Surveying supervision must master the design drawings, project division, construction progress and operation mode, and often go deep into the site to communicate with construction personnel to master the demand of engineering progress for surveying work. The control means, scope, depth and methods of the survey supervisor can be based on his comprehensive grasp of the working attitude and technical level of the contractor's surveyors, as well as his profound understanding of the importance, repeatability, measurement process and the formation principle of the results, and adopt methods such as comparative survey, sampling inspection of the results, comprehensive inspection by other parties, joint survey, data mutual inspection and direct acceptance. Paper test. If the contractor has a strong technical force and a serious working attitude, the intensity and scope of monitoring can be appropriately reduced, and sampling inspection and letter acceptance can be adopted. It is necessary to strengthen guidance for those with low technical level, so as to improve them rapidly and reduce the difficulty of supervision in the future. Those who are prone to fraud should be monitored throughout the process and the original data should be retrieved at the first time. After excavation, the original terrain will be destroyed, so the joint survey should be carried out in advance to ensure the accuracy of the engineering quantity measurement foundation, and the excavation opening line should be mainly checked to avoid major construction mistakes. For key parts, hidden parts, structural parts with high accuracy requirements and parts that cannot be re-measured, joint measurement should be carried out in time to ensure that accurate, reliable and complete basic data can be obtained in time. For the first field survey, it is necessary to comprehensively supervise the work, observe whether its operating procedures, operating methods, readings and calculations are correct, and correct the existing mistakes in time. The instructions of the contractor's leaders to its surveyors must be observed and understood to prevent the surveyors from changing and fabricating the measurement data and results due to the pressure of the project department. According to the needs, the contractor's wrong measurement behavior can be corrected on the spot, and instructions, notices and warnings can be issued to the contractor, or opinions can be put forward through reply. Combined with on-site supervision, control and restrict the contractor's behavior of not accepting or delaying the execution of supervision instructions, report major problems, universal problems, problems of violating commitments and long-delayed problems in measurement to the director in time, and hold special meetings to solve them.

Post-event control is strictly controlled. The measurement and acceptance of engineering foundation surface, the quality evaluation of building forming retest and the review of measurement documents all belong to post-event control. If we maintain this level, we can accurately evaluate the design compliance of the project, and if necessary, we can ask for rework. With the support of the director, it is sometimes very effective to use the means of payment control reasonably and implement the control intention of survey supervision.

Through active intervention in advance, multi-means control in the process and strict control afterwards, the supervision departments of North China Hydropower Supervision Center have achieved the supervision effect of timely and reliable measurement guarantee, accurate and complete data and undisputed measurement acceptance results.

Commencement preparation stage: this stage is short, so the survey supervisor should enter the state as soon as possible, fully spread the pre-control work, and complete the survey preparation work before commencement. The specific work is as follows: ① Participate in the preparation of supervision plan under the auspices of the director, prepare the detailed rules for the implementation of professional supervision, and report to the owner; (2) After attending the first site meeting, the director will arrange supervisors to inform the contractor and establish working contact; (3) Receive and review the data of survey control network forwarded by the Employer, review whether the coordinate system of design drawings and height system are consistent with the control network or whether there is a clear conversion relationship, and consult and clarify in time when problems are found; (4) With the support of the director and the technical department, organize the symposium on investigation work, establish business contacts, formulate work disciplines, work systems and work procedures, and clarify work specifications and record formats; ⑤ It is required to submit and review the contractor's measuring organization, internal calibration system, technical qualifications of personnel and instrument verification data, and urge them immediately if they are found not to meet the requirements; ⑥ Entrusted by the owner, complete the handover of control network and site side piles one week before commencement, and release the results of control network. Paper test. Supervise the control network review and control network encryption, timely review and approve the submitted results, and deal with problems quickly when found; ⑦ Participate in design disclosure, be familiar with the approved construction progress plan, master the design drawings of the construction site, calculate the conversion relationship between construction coordinates and axis pile number, master the key and difficult points of project lofting, and study the special survey scheme; (8) Organize the joint survey of the original terrain and the original section, sign the joint survey data, and review the submitted surveying and mapping data as the measurement basis; Pet-name ruby on-the-spot verification of excavation opening line lofting, can provide reference for the chief supervision engineer to issue the commencement order.

Actual construction stage: this stage mainly ensures the correctness of construction lofting and completes acceptance measurement in time. The specific work includes: ① checking the slope gradient and floor elevation of excavation, accepting the specifications and elevation of excavation foundation, and providing survey supervision opinions for the acceptance of concealed works; (2) Participate in the joint measurement of monthly receivers, review the measurement data, and approve the number of monthly receivers; (3) Check the setting-out of the casting template to provide a basis for the site supervisor to issue a certificate of opening the warehouse; (4) Participate in the joint measurement of building forming, and provide measurement data and conclusions for the design compliance and appearance quality evaluation of engineering specifications; ⑤ Acceptance measurement of backfill foundation surface, acceptance of backfill recipient, acceptance of backfill finished surface and joint survey of topographic map of finished surface; ⑥ Quality evaluation data measurement; ⑦ Deformation observation; (8) Joint measurement and collection of claim prevention data; Pet-name ruby yard storage, stacking, transportation and other measurement; Attending the audit of completion settlement data; ⑾ supervision data sorting, survey supervision work summary; ⑿ If there is any tunnel construction, the site work includes digging, lofting or laser aiming, under-excavation inspection, convergence monitoring, section acceptance, through measurement, initial support lofting, shotcrete surface acceptance measurement, steel formwork trolley lofting adjustment and forming acceptance. Among them, breakthrough measurement is the key.

Because the project is completed step by step, and the quality evaluation is also carried out according to the unit, division and unit project, the completion measurement runs through the whole construction period.

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