Multi-point displacement meters are widely used in deformation and displacement monitoring of slope rock mass and cavern rock of water conservancy and hydropower projects, which can realize automatic monitoring and safety warning. The new multi-point displacement meter device introduced in this article is a new structural type different from the old described in DL/T 1272—2013, including an anchor head, a transmission rod (steel pipe) and a plastic protection tube installed with concentric shafts, as well as the orifice mounting base and the matching displacement sensor. Its application range and measurement accuracy are exactly the same as the multi-point displacement meter device, and its technical performance is superior. It has advantages such as high equipment precision, easy installation and high observation accuracy. Moreover, one of its important technical achievements is realization of the dual functions of manual instrument measurement and automatic measurement by displacement sensor, which can be used to verify the automated measurements and realize the continuous observation by use of the manual measurement data during replacement of the displacement sensors.

Discussion was made on fitted line parameter of a sensor by different ways, so as to understand the meanings of the linearity in hydraulic monitoring sensor and the effect of different linearity in measurement using sensor or calibration sensor.

After years' operation, seepage may occur at earth dams. This paper analysed the types and cause reasons for seepage, and, accordingly, advanced some preferred treatment schemes and issues calling for attention in construction, for reference.

Claim opportunity identification is the key part of claim management. This paper focuses on the application of cost and schedule analysis to international projects. Combined with theoretical analysis and case study, the paper elaborates claim opportunity identification.

As the second largest hydropower station in China, Baihetan hydropower station has a total installed capacity of 16 000 MW. It has the characteristics of high water head, large installed capacity and large HD value. To ensure its safe operation, 38 900 tons of steel were used to make penstocks, including 10 100 tons of 800 MPa high-strength steel. This is the first case where thickness of 800 MPa penstock reaches 68 mm in domestic hydropower industry. By studies on 800 MPa high-strength steel and a large number of tests, it is proved that the use of 800 MPa high-strength steel meets the function requirements of large power stations.

The open-hole type is generally used to monitor water pressure in the body of earth-rock dam,the lag effect of water level in the hole can’t be ignored in data analysis.There are several ways in data analysis,this article sums up some ways of qualitative analysis,and describes the different represent when the dam seepage is out of the way.

It is the first vast application of low-heat cement in the concrete used for construction of a 300 m super-high double curvature arch dam. Through the research and application of low-heat cement and low-heat cement concrete, the performance characteristics of concrete in the construction process have been comprehensively mastered. By giving full play to the characteristics of low-heat cement such as low hydration heat, high strength and good durability, the overall quality of concrete construction of Baihetan hydropower station has been effectively guaranteed.

During investigation, design, construction and operation of tunnels, due to constraints and mistakes, failures happen. There are 10 cases at home and abroad presented in this paper, as well as the cause reasons and the lessons learned, for reference.

Under the long-term complex natural condition and the effect of various both inner and outside forces, the state of earth-rock dam is changing momentarily and safety trouble may generate without obvious prewarnings. Especially, because of careless design, poor-quality construction and unsuitable management, security of earth-rock dams built earlier after the country founded have many problems. So it is very significant to give a safety appraisal to existing earth-rock dam for the sequential maintaining and reinforcing work to protect downstream dwellers’ lives and their properties. And this article will take Jinji reservoir and dam of Jingmen City in Hubei province as an example so show the method and content of safety appraisal of earth-rock dam.

This paper focused on the main characteristics and seepage causes of diseased embankment dams. By introduction of the mechanism and effect of some treatment methods, such as grouting and concrete anti-seepage wall, the paper put forward some optimized programs and pointed out the issues that attention should be paid to in construction, for reference.

Double- metal marks were usually used as the base point of vertical displacement measurement of dam. This article discussed the factors that affect its running, such as design and installation, and then put forward some methods for improvement and advice on structure, worthy reference to designer, construction company and equipment company.

The height of Sanbanxi face-slab rock-fill dam is 185.5 m．With low storage water level, the seepage was less than 30 L/s．As water level rising rapidly in the flood season of 2007, the seepage increased, whose maximum was 303.10 L/ s.By underwater inspection, damage was found at the horizontal joints of the face－slab.Later, rehabilitation was carried out and good effect was gotten.This paper, combined with seepage monitoring data, analysed the seepage of the dam before and after the rehabilitation.

The rock- bolted crane beam in underground powerhouse of Baihetan hydropower station is designed by use of rigid body limit equilibrium method and checked by finite element method, which verifies the rationality of design parameters of structural section and bolt. Due to the influence of complex geology and high in-situ stress, the excavation of rock-bolted crane beam in local area is difficult, so the technical measures of rock platform excavation and reinforcement are put forward. Analysis of the prototype observation results shows that the bolt stress of rock-bolted crane beam and the opening between crane beam and surrounding rock have met the requirements. During the load test, the increase of monitoring data is small, which verifies the rationality of the design method and construction measures of rock-bolted crane beam.

Crest settlement reservation of concrete face slab rockfill dams would effect flood prevention safety and visual image.Some dam crest elevation was found lower than design in operation as there was no settlement reservation in design, while some recorded settlement in operation exceeded the designed value as the settlement reservation in design was too small. By statistics of dams, the recorded settlement value was more than 0.1% of damheight. For enough settlement reservation in operation and good visual image of arch at middle part, settlement reservation no less than 0.5% of damheight was recommended.