As an important space carrier to participate in global competition, the Guangdong-Hong Kong-Macao Greater Bay area is facing the pressure from the energy demand and environment protection. Developing geothermal resources is an effective way to solve the problem. In this paper, the possibility of geothermal development in Greater Bay area was reasoned, based on the analysis of regional geotectonic, stratigraphic lithology and geothermal field. Considering deep ground temperature, rock thermal physical parameters and terrestrial heat flow, geothermal water resource and hot dry rock resource were quantitatively assessed through raster units. Further, high potential geothermal zones were distinguished. Results show that:1) the intersected fault structures and widely distributed granite in the Greater Bay area provide a favorable geological environment for the storage and formation of geothermal resource, which is verified by the measured terrestrial heat flow; 2) the computing results indicates that temperature would be over 70 at depth of over 1.3 km and 168.81~233.61 at depth of 5 km, showing a high potential of geothermal resource; 3) The estimate geothermal resources in the Greater Bay area amount to 5.83×1017 kJ within the depth of 5 km. It is equivalent to the thermal value of standard coal of 5.94×109 t and can reduce the emission of CO2 by 4.04×109 t, when recovery rate is set at 30%. 4) The area of high potential geothermal resources is mainly distributed along the northeast deep fault, i.e. in Foshan, Zhongshan, Jiangmen, Shenzhen and Hong Kong, where the unit geothermal resource potential is equivalent to standard coal of 5.19×105 t per square kilometer, and should be taken as key area for geothermal prospecting and exploitation..
There are few in-situ creep test data of tunnel anchor for suspension bridge. To obtain the creep deformation law of tunnel anchor of Xingkang Bridge on Yakang Expressway and enrich creep test data of tunnel anchor of super-large suspension bridge, creep tests of 1∶10 in-situ shrinkage model of the Ya’an side slope tunnel anchor of Xingkang Bridge were carried out, based on the specific geological conditions in the Ya’an side slope tunnel anchorage area of Xingkang Bridge and the similar theory of elastic mechanics. According to the creep characteristics of the model anchor and surrounding rock mass under 1.0P, 3.5P and 7.0P loads, the whole creep process of the model anchor, surrounding rock and interfacial dislocation were analyzed. The results show that under 1.0P, 3.5P and 7.0P loads, the maximum creep deformation of anchor body was 0.62 mm, 0.97 mm and 1.58 mm, the maximum creep deformation of surrounding rock was 0.49 mm, 0.85 mm and 1.38 mm, and the maximum creep deformation of anchor body and surrounding rock was 0.15 mm, 0.64 mm and 1.43 mm, respectively. On the basis of in-situ scale tests, the three-dimensional viscoelastic-plastic numerical analysis of the interaction between anchorage and surrounding rock mass was carried out by using FLAC3D finite element software. The comparison between the field measured values and numerical analysis results shows that the measured creep deformation and calculation results of the anchorage and surrounding rock of the Ya’an side bank slope tunnel of Xingkang Bridge have the similar evolution trends and range of amounts. The creep of tunnel anchorage and surrounding rock mass of Xingkang Bridge on Yakang Expressway belong to stable creep stage under various loads. The long-term stability of suspension bridge was not affected by the creep of anchorage and surrounding rock mass. The test results provide a basis for the reliability evaluation of the tunnel anchorage system of Xingkang Bridge, and also provide a reference for similar engineering designs..