Abstract:This article proposes a new combined supporting system—the slope protection pile and the compound soil nail wall with micro steel pipe piles， which successfully solved the technical difficulties such as necessity of vertical excavation around the foundation pit due to no grading space， great depth of the foundation pit， requirement for small displacement， and high support costs. In addition， the system provided convenient construction， and was beneficial to control of the displacement and deformation of the slope， and enhancement of the overall stability of the slope without impact on the surrounding environment during the excavation of the foundation pit. The design and construction with this support method was tested for a project in Beijing， and the monitoring results were good with great improvement in the safety and stability of the slope； thus， verifying the feasibility of the support form. It has technical and economic advantages that conventional soil nail walls and slope protection piles cannot compare to in deep foundation pit support. It can be used as a reference for other similar projects， and has high application and promotion value.

Abstract:The pile-anchor supporting structure system is a supporting method which combines slope protection piles with soil anchor bolts. It is widely used in slope and deep foundation pit support due to its safety and economic characteristics. However, its application in ultra-deep foundation pits is still under exploration. According to the engineering geological conditions and hydrogeological conditions at the foundation pit of Fengcheng International Trade Project, taking into account of its surrounding conditions, and with comparison of several different foundation pit support plans, the pile-anchor supporting system was selected, which is technically feasible, economically reasonable, provides good overall performance and is convenient for the excavation of foundation pits and subsequent construction. Then the soil pressure calculation, cast-in-place pile design, anchor bolt design and stability checking calculation were carried out for the foundation pit supporting structure. Later deformation monitoring verified that the pile-anchor support was safe, economical and feasible for the ultra-deep foundation pit.

Abstract:Based on the deformation monitoring results of the extra deep foundation pit at Yanggaozhong Road station of Shanghai subway line 18, the deformation regularity of the deep foundation pit retaining structure is discussed from the aspects of the horizontal & vertical displacements of the retaining structure and the vertical displacement of the column pile. The analysis shows that with the layered excavation of the foundation pit, the horizontal displacement curve of the retaining structure shows a “big belly” shape, the maximum displacement point constantly moving downward, and finally being stable at about (093～107) times the excavation depth; the maximum horizontal deformation is about 330‰ of the excavation depth; the everage maximum bulging deformation is about 052‰ of the excavation depth; the column is bulged with the displacement about 091‰ of the excavation depth. All the deformation is basically consistent with the deformation trend of monitoring data in peripheral pipelines, so the above-mentioned regularities are expected to be reference for the design and construction of similar projects in the future.

Abstract:Soil deformation in landslide and the treatment are important in the landslide control construction. Taking a landslide hazards control project in Dongyuan of Lanxi City as an example, this paper introduces a series of measures adopted for the local instability occurred in the construction process, including the analysis on the recent soil deformation characteristics and the reasons, emergency rescue measures, monitoring of emergency evacuation effects and subsequent construction plans, etc. These measures have achieved good results and provided reference for the similar construction.

Abstract:In order to study the application effects of Beidou satellite measurement technology in the displacement monitoring for deep foundation pit construction, with an example of deep foundation pit project in Liuzhou City, the paper introduces the advantages of BDS system and conventional measuring method, the composition of foundation pit monitoring system, measuring points selection, monitoring methods and the effects. The research shows that GNSS technology, in which BDS is the key, can meet the requirements of accuracy and reliability, and is suitable for the displacement monitoring of foundation pit.

Abstract:With the construction case of network media building in Henan, the paper introduces the design selection process of deep excavation and the construction situation. Analysis is made on the results of deformation monitoring about horizontal deformation at top edge of excavation, horizontal deformation of the crown beam and cable tension. Some suggestions are put forward to the design of pile-anchor structure and construction.

Abstract:The paper summarized the damage causes of loess foundation pit, and took the example of a retaining project to sum up the geological situation of construction and the retaining methods. Based on the foundation pit damage model, the stability computation was made and designing parameters were adjusted to determine the final scheme. The retaining scheme was introduced including the application of composite soil-nail technology and monitoring on the foundation pit deformation. The construction experience was also presented.

Abstract:Starting with traditional technology method, the special measuring technology and the newest survey technology, this article introduced several common methods and technical means for geological hazard deformation monitoring in Three Gorges reservoir region nowadays. And comparison was also made on advantages and disadvantages of different methods and technical means in different geological hazards.

Abstract:Deformation monitoring is an important means to monitor the safety of deformation, and the basic function is to collect dynamic displacement information through deformation measurement. According to the information, analysis and determination can be made on early-warning to dangerous situations. Analysis was made on F testing method of stability of basic benchmark of GPS deformation monitoring study. Based on the sliding monitoring engineering in Yunyang County, analysis on stability of basic benchmark of GPS landslide deformation monitoring networks was also made.

Abstract:TBM boring machine is widely applied in tunneling excavation with its high speed, high efficiency, high safety and good quality, it is especially suitable for deep-lying long tunnel, but drives slowly in unfavorable geological tunneling section. In this case, special technical methods should be taken according to the surrounding rock characters, verification should be done to verify supporting method and design parameters. Summery was made in geological forecast method, treatment measures and deformation monitoring method in unfavorable geological tunneling condition with field case.