The northern Guangdong-southern Hainan region is located at the intersection of Eurasian Plate, Pacific Plate, and Indian Plate. Since Late Mesozoic, this region has been influenced by multiple phases of tectonic activities. Its thermal evolution history has garnered widespread attention due to its ability to constrain regional tectonic evolution process. This study has collected, compiled, and processed published low-temperature thermochronological data from northern Guangdong-southern Hainan region using inverse distance weighting(IDW) interpolation method. By analyzing the age distribution and thermal history inversion modeling results, it restores its thermal evolution history since Late Mesozoic ( approximately 150 Ma) and explores the associated tectonic process. The thermal history of Hainan Island can be broadly divided into four stages: two episodes of very rapid cooling rate at 110-90 Ma and 40-20 Ma, interspersed with two periods of thermal stability at 90-40 Ma and from 20 Ma to present. The thermal history of Guangdong Province can be broadly divided into three phases. South of Gaoyao-Huilai Fault Zone, the thermal history exhibits one phase of relatively rapid cooling at 150-80 Ma, a period of thermal stability at 80-50 Ma, and two episodic cooling after 50 Ma. Between Gaoyao-Huilai Fault Zone and Xijiang River, the thermal history shows one phase of very rapid cooling at 120-80 Ma(reaching extremely rapid cooling in some areas), followed by a phase of very rapid cooling with minor temperature fluctuations at 30-10 Ma. North of the Xijiang,the timing of the first rapid cooling stage varies across different areas, occurring at 120 -100 Ma, 80-60 Ma, and 50-30 Ma. It is noted that there is a rapid cooling period around 10 Ma in all these areas. The thermal evolution of northern Guangdong-southern Hainan region since Late Mesozoic is likely to be related to Late Mesozoic subduction of Paleo-Pacific Plate, the Early Cenozoic rollback of Pacific Plate, and the Early Eocene collision of Indian-Eurasian Plates. Additionally, Hainan Island may have been further influenced by Philippine Plate and Paleo-South China Sea tectonics.

Traditional prediction methods cannot extract local features of multi-factor time series. A prediction model that combines convolutional neural network(CNN) and long short-term memory network(LSTM) is proposed. Fifteen influencing factors are selected from geological parameters, tunnel geometry parameters, and shield tunneling parameters to form a multi-factor time series as input data. To predict the surface subsidence, CNN-LSTM algorithm is used. Taking the construction data of Changsha Metro Line 6 as an example, the prediction results of the CNN-LSTM model are compared and analyzed with those of traditional BP neural network, CNN, and LSTM models. The results show that the CNN-LSTM hybrid model performs better in predicting surface subsidence, with a maximum prediction error of only 9. 58%, which is significantly lower than other models. After comparing and analyzing the predictive performance of the four models mentioned above, it is found that the CNN-LSTM hybrid model has good performance in prediction accuracy, generalization ability, and stability.

Limestone slopes are highly susceptible to karstification and the detection of its karst characteristics is of great significance for elucidating water resource regulation mechanisms, karst water migration patterns, and ecological environment management in karst areas. A comprehensive method is conducted on the karst development characteristics of limestone slope in Chenqi, Puding County, Guizhou Province, integrating electrical resistivity tomography(ERT), ground penetrating radar(GPR), and geological drilling technology. A total of 7 resistivity inversion images at different positions of the slope are obtained through ERT, and the development degree of karst fissures is analyzed by integrating GPR data profiles, this research ultimately reveals the overall karst development characteristics of the study area. The results show that the karst development in limestone slope land exhibits significant spatial heterogeneity, with pipe-type karst predominantly developing in the middle of the slope land. Electrical resistivity tomography(ERT) effectively identifies the karst spatial distribution characteristics of limestone slope and by combining ground penetrating radar technology, it can further enhances the resolution of detecting karst development intensity and fracture development. Geological drilling technology is an effective mean to verify the applicability of these two methods. 

The application of geological big data in 3D geological structure modeling is explored, with Chengdu taken as an example. By utilizing the achievements of geological big data in Chengdu, this paper adopts a 3D modeling method of multi-source data fusion to construct 3D geological structure models at two scales of municipal administrative region and built-up area. Through 3D model data, it extracts four important geological structural planes and geological bodies such as faults, base-cover interfaces, fine-grained soil, and pebble soil. Their 3D spatial structure change characteristics are analyzed. The research findings can provide a scientific basis for land spatial planning, underground space development and utilization, and site selection for major projects in Chengdu.

The Jurassic tectono-thermal evolution in northern Guangdong Province has generated abundant magmatic rocks, yet their petrogenetic mechanisms remain debated. This study investigates the magma source and its tectonic significance of Aizi granite in northern Guangdong by integrating LA-ICP-MS zircon U-Pb dating, trace element analysis, and zircon Lu-Hf isotopic data complemented by whole-rock Rb-Sr and Sm-Nd isotope analysis. The aim is to refine the genetic model for A-type granites formed under the Pacific Plate subduction setting during Late Jurassic. The Aizi granite yields a LA-ICP-MS zircon U-Pb age of 155±1 Ma(MSWD= 0. 12), indicating its formation during the Late Jurassic. The zircons exhibit negative εHf(t) values(-10. 4 to -4. 6), relatively high but slightly lower ( 87 Sr/ 86 Sr)i ratios(0. 713 1-0. 713 9) compared to the Mesoproterozoic basement of Cathaysia block, and zircon Hf crustal model ages(TDM2 = 1 490-1 856 Ma) that are older but marginally younger than Mesoproterozoic basement of Cathaysia block, suggesting that the magma source of Aizi granite is originated from ancient crustal materials with a small amount of mantle material added. The regional tectonic setting analysis indicates that Aizi granite is formed under the subsidence background of low-angle subduction of the Pacific plate slabs, triggered by asthenospheric upwelling that has induced partial melting of the upper crust in the weakened back-arc basin zones of Cathaysia ancient block, ultimately forming syenogranite.

Pajiang uranium deposit at the southwestern margin of Fogang granite is located in southern part of Taoshan-Zhuguangshan metallogenic belt. The metallogenic geological conditions and ore-controlling factors of uranium deposit have not been systematically studied, and a uranium ore prospecting model has not been established, which has restricted the further prospecting. Based on the field geological investigation of the uranium deposit, this paper analyses the ore-controlling factors of the uranium deposit and establishes a prediction geological model in the area using the“trinity”prospecting theory. The results show that: ①Uranium mineralisation in Pajiang uranium deposit is mainly controlled by granitic bodies, faults, and hydrothermal alterations. The medium-fine grained two-mica granite and fine-grained two-mica granite in the deposit are important metallogenic geological bodies, which provide material source for uranium mineralisation. ②The near-EW-trending Shegang fault and Zhuyuan faults are ore-conducting faults. Uranium mineralization occurs mainly in the NNW-trending No. 17 and near NS-trending No. 5 fault zones. The branching and compound locations of faults, as well as the sections where the dip angle changes from steep to gentle, are the main space occurred for the uranium ore bodies, forming important metallotect and ore-forming structural planes. ③Hydrothermal alteration closely associated with uranium mineralisation in the ore deposit includes silicification, hematitization, and purple-black fluorite alteration, which are often ore-bearing areas. Two typical ore mineral assemblages are identified within alteratim zones, microcrystalline-quartz-hematite-pitchblende and the dark red microcrystalline quartz-pyrite-dark purple fluorite-pitchblende. The predominant types in this region are the silicified vein type uranium deposits. ④The model indicates that under the condition of fault activity in the Late Cretaceous, the mantle-derived F-rich fluids mixed with atmospheric precipitation migrated along the nearly east-west fault structures and interacted with the surrounding granites, activating uranium in the rock mass to enrich the fluid. The ore-forming hydrothermal fluids then migrated and precipitated along the ore forming structures and planes, culminating in the formation of uranium ore bodies.

The coastal zone of Guangxi is an important coastal placer metallogenic belt in China, with significant potential for zirconium-hafnium(Zr-Hf) resource occurrence. However, its distribution patterns and prospecting directions await systematic research. Based on data from Guangxi regional geological surveys, Zr-Hf ore potential surveys, general surveys, and studies on the source-sink system of Quaternary sediments in marine areas, this paper integrates multi-source data including heavy mineral geological survey data, mineral geological drilling data, chronostratigraphic data, and geochemical data and combines the analysis of typical ore deposits to systematically examine the distribution characteristics and metallogenic conditions of Zr - Hf deposits in the Guangxi coastal zone. The research reveals that Zr-Hf deposits in the region are dominated by coastal placers, with grades ranging from 0. 31 to 2. 68 kg / m 3 . They are concentrated in the following areas: coastal terraces of the Dafeng River estuary, coastal terraces of the Nanliu River estuary, fluvial terraces in the middle and lower reaches of Nanliu River, Qinzhou Bay estuary-bar system, Fangchenggang estuary-bar system, nearshore metallogenic belt of Lianzhou Bay, and nearshore metallogenic belt of Fangchenggang Bay. Mineral enrichment is controlled by material source supply, hydrodynamic sorting, and Quaternary sedimentary environments. Chronostratigraphic data indicate that the material sources in this area are extensive, primarily Indosinian granite, and influenced by multi-stage tectonic evolution. Geochemical anomalies show a strong correlation between Zr-Hf elements and Ti, with these elements mainly distributed in clay and clay-bearing strata. This study proposes a “tectonics-material source-sedimentation-hydrodynamics” four-factor ore-controlling model, which provides a scientific basis for the exploration and development of Zr-Hf resources in the Guangxi coastal zone and is of great significance for ensuring the supply of strategic mineral resources.

The calcite-otavite solid solution(Ca1-xCdx)CO3 is synthesized and its dissolution in air-saturated water at 25 ℃ for 270 d is experimentally explored. During dissolution, the aqueous Cd 2+ concentration increases to the peak value of 0. 082-11. 102 μmol / L in 6 h, and then declines slowly to stable state of 0. 026-1. 334 μmol / L after 210-270 d dissolution. Cd 2+ / (Ca 2+ +Cd 2+ ) mole ratio of the aqueous solution is greatly lower than Cd / (Ca+Cd) mole ratio(XCd ) of the corresponding solid showing a strong non-stoichiometric release of calcium and cadmium. At 25 ℃ , the solubility product(Ksp ) and Gibbs free energy of formation(ΔG ° f ) are determined to be 10 -8. 40±0. 02 to 10 -8. 40±0. 01 and - 1 129. 40 ± 0. 11 to - 1 129. 38 ± 0. 04 kJ/ mol for calcite ( CaCO3 ), 10 -11. 59±0. 07 to 10 -11. 51±0. 17 and -671. 61 ± 0. 45 to - 671. 18 ± 0. 99 kJ/ mol for otavite (CdCO3 ), respectively. With the increasing XCd , the Ksp value declines non-linearly from 10 -8. 40±0. 02 to 10 -8. 40±0. 01 for calcite to 10 -12. 13±0. 09 for (Ca1-xCdx)CO3 solid of XCd = 0. 90, and then increases slightly to 10 -11. 59±0. 07 to 10 -11. 51±0. 17 for otavite; while the ΔG ° f value increases linearly. Lippmann diagram is constructed for (Ca1-xCdx)CO3 solid solution with the estimated Guggenheim coefficients a0 = -2. 36 and a1 = -6. 89. The solid dissolves non-stoichiometrically and the aqueous solution moves progressively up to solutus curve and the minimum stoichiometric saturation curve for pure otavite, from right to left, finally approaches the intersection region of stoichiometric saturation curves for pure calcite and (Ca1-xCdx)CO3 solid solutions(XCd = 0. 21-0. 90). The substantially Cd-poor aqueous solution is lastly in equilibrium with CdCO3 -rich solid.

Aiming at the engineering problems of low strength and poor water stability of silt in the Yellow River area, a curing agent(SBCG) is prepared with steel slag, granulated blast furnace slag, and desulfurized gypsum as the main materials to improve and solidify the Yellow River alluvial silt. The road performance of SBCG-solidified silt is comprehensively evaluated by standard unconfined compressive strength, water immersion softening, freeze-thaw cycles, etc. , and the internal microstructure of solidified silt is observed by SEM. The results show that the incorporation of SBCG can significantly improve the road performance of silt. The solidified silt is easier to be compacted than plain soil, and the standard curing strength of each age is significantly improved with the increase of SBCG content. The loss rate of water immersion strength at 3 d age is less than 20%. The CBR after immersion still meets the subgrade strength requirements. The residual strength ratio after melting cycle is not less than 80%. According to the change law of strength of solidified silt under different test conditions, it is determined that the content of SBCG can be controlled below 10%. The SEM images show that SBCG can be hydrated inside the silt to form a large amount of hydrated calcium silicate gel(C -S -H), which is wrapped around soil particles, and ettringite(AFt) is filled in pores, making the silt form dense cementation. The structure is beneficial to the improvement of water stability and frost resistance.

The ecological texture serves as the carrier and identity of the distinctive features and cultural heritage of traditional villages around scenic areas. Its degradation is irreversible, making it particularly crucial to understand its vulnerability. Using vulnerability theory, this study establishes an analytical path and assessment framework for the ecological texture vulnerability of traditional villages around scenic areas. Based on vulnerability survey data and focusing on the three elements of exposure, sensitivity, and adaptability, the mechanism of ecological vulnerability is summarized and its connotation is clarified. By integrating field surveys, quantitative analysis methods, and spatial planning theories, and through analyzing the current survival environment and state of the villages, the spatial manifestations, causes, and external driving forces of their vulnerability are examined. From the two dimensions of external and internal influencing factors, the spatial logical association of ecological texture vulnerability in traditional villages around scenic areas is constructed, and a system of influencing factors for this vulnerability is deduced. The key factors for ecological texture protection lie in the superimposed external influence of the unique tourism-driven effects from the scenic area. Under this influence, multiple key factors are formed, including the ecological and social values of the village and tourist behavior. Compared to the relatively stable factors of physical spatial conservation, these factors more prominently highlight the ecological sensitivity of traditional villages around scenic areas, enhance the sustainability of conservation for such villages, and provide rational decision-making support through suitability assessment for their revitalization and utilization.

In order to solve the problem of UHPC shrinkage, magnesite calcination is used to prepare magnesia expansion agent(MEA), and the effects of calcination temperature-holding time and calcination-powder grinding sequential relationship on the activity of MEA samples are investigated. Based on the above results, MEA samples with different activities are prepared and mixed into ultra-high performance concrete(UHPC) for compressive strength and shrinkage performance testing. The results show that the decomposition rate of magnesite increased with the increase of calcination temperature and holding time. With the increase of calcination temperature and holding time, the crystallinity of MEA becomes higher, structure will be denser, and the activity decreases. Under the same calcination temperature and holding time, the structure of MEA prepared by the burnand-grind method is sparser and more active than that prepared by the grind-and-burn method. The compressive strength and shrinkage value of UHPC decreases with the increase in the activity of MEA. When the early autogenous shrinkage of UHPC doped with 6% of the highest activity, Ⅰ-MEA1 can be reduced by 33. 31%.

In order to study the effect of soil particle gradation on the water characteristic curve of porous media, the finite element analysis method is used at the pore scale to conduct numerical simulations of water absorption process and dehydration process for three kinds of graded soil:well-gradation, poor-graded soil and equal particle size. In the simulation of water absorption, among the three graded soil, poor-graded soil has a higher water saturation rate while well-graded soil has a stronger water holding capacity; when simulating dehydration, soil with equal particle size has a smoother fitting curve of water characteristics, making it more difficult to dehydrate. On a microscopic level, the water phase behovior as the capillary retention water within the pore channel, and the contact angle effect and the “ink bottle” effect are the primary causes of the water hysteresis phenomenon. The influence of good-graded soil and poor-graded soil on the water characteristic curve mainly lies in the “ink bottle” effect.

To investigate the variation law of mechanical response of the graded crushed stone base stabilized with low cement content, the mechanical response characteristics of graded crushed stone structural layer stabilized with low cement content under different asphalt pavement structures are comparatively analyzed by using a meshless numerical simulation software. It is found that the mechanical parameters such as deflection and bottom stress of the new and reconstructed asphalt pavement structure changes with the difference in thickness and modulus of the low cement content stabilized graded crushed stone base. Thickness has a greater impact on bending and bottom stress than modulus, and the low cement mixing base is mainly compressive under different pavement structures. The results show that the low cement content of upper base layer improves the structural stress state of pavement, and the thickness should be controlled at about 20-30 cm, the modulus should be controlled at about 800 -1 000 MPa, and the cement content will be controlled at 2. 0%-2. 5%. In the case of ensuring the low cement content base under pressure, the deflection and tensile stress at semi-rigid structural layer should be used as the control index.

Dupangling area is located in the compound position of NW-trending Qinhang metallogenic belt and EW-trending Nanling metallogenic belt, with strong tectono-magmatic activity and favorable metallogenic conditions. Although a lot of geological and mineral surveys have been carried out by previous researchers, no major prospecting breakthrough has been achieved in this area. The main reason is the insufficient research on regional comprehensive metallogenic prediction, and the exploration data are not effectively used. In particular, it is not closely integrated with big data and other information technologies. On the basis of summarizing the metallogenic laws of Dupangling tungsten-tin polymetallic deposits, this paper extracts the main ore-controlling factors, selects the evidence factors, determines the classification criteria of ore-forming potential, and carries out prospecting and prediction based on weight of evidence method. In this study, 25 ore-controlling factors (evidence factors) in 6 categories such as strata, rock mass, structure and geochemical exploration are extracted, 24 oreforming prospect areas are delineated according to the posterior probability value, and the ore-forming potential, ore-forming geological setting, mineralization alteration and anomaly characteristics of geophysical, geochemical and remote sensing are also used. The region with similar metallogenic conditions, deposit genesis and geological, chemical and remote ore-forming information is divided into a prospecting and prediction area. Based on the above principles, there are 5 optimal prospecting prediction areas in Dupangling area, including 2 grade Ⅰ prospecting prediction areas and 3 grade Ⅱ prospecting prediction areas, among which the grade Ⅰ1 prediction area on the west side of Qianjiadong has the most prospecting potential.

The strong thixotropy of Zhanjiang Formation structural clay causes the obvious time effect of pile foundation settlement, and there is a large error between measured value and calculated value obtained according to existing pile settlement timeliness calculation method, the applicability of existing pile foundation settlement timeliness calculation method is challenged in Zhanjiang Formation structural clay. Taking the pile foundation in Zhanjiang Formation structural clay as research object, pile foundation settlement time effect model experiment and pile side soil thixotropy experiment are carried out, the time effect coefficient of pile foundation settlement and thixotropic strength ratio of pile side soil at different standstill times are obtained, and the quantitative relationship between time effect coefficient of pile foundation settlement and thixotropic strength ratio of pile side soil is fitted. Based on hyperbolic model method, a calculation formula for time effect of pile foundation settlement considering thixotropy of Zhanjiang Formation structural clay is proposed, and the effectiveness of this calculation formula is verified by experiment and referenced data. The result shows this calculation formula can narrow the error between calculated and measured value of pile foundation settlement after a long-term load in actual project and provides a reference for the time effect calculation of pile foundation settlement in Zhanjiang Formation structural clay.

Taking the nonuniform surface subsidence data of the Panyu Plaza construction section of Guangzhou subway line 22 as an example, autoregressive moving average(ARIMA) model and Gaussian process regression (GPR) model are used to analyze and predict the change of surface subsidence. Firstly, the training set data is used to establish ARIMA model, determine the ARIMA(3, 1, 2) model and predict its linear subsidence, and then GPR model is used to train the ARIMA model residual and predict its nonlinear value. The predicted value of surface subsidence is obtained by adding the predicted values of the two models. The results show that the prediction error of ARIMA-GPR mixed model is significantly reduced compared with ARIMA and GPR single prediction models, and the prediction accuracy is improved by above 40%, which improves the prediction accuracy of single prediction model. Therefore, ARIMA-GPR mixed model is an effective and feasible method for nonuniform subsidence prediction.

With the gradual increase in the scale of substation construction and the types of transmission and transformation components, it is difficult to meet the needs of massive 3D data rendering of substations only relying on the upgrading of computing and storage capabilities. Optimizing the scheduling of 3D scene data is an indispensable means to improve rendering efficiency. Through analyzing the spatial storage structure of loose octree and combining with visual correlation dynamic LOD technology, a dynamic scheduling method of substation scene model based on loose octree is proposed. This method takes the sight distance as the constraint condition, indexes the loose octree nodes from top to bottom, simplifies the objects in the qualified nodes to the corresponding LOD level, and improves the rendering rate of 3D scene of the substation by reducing the amount of model data. Finally, taking a substation project as the research object, a fast rendering of 3D substation scene is realized based on Unity 3D, which verifies the effectiveness of the dynamic scheduling method.

To achieve accurate monitoring of cable forces during the construction of bridge cables, a method is proposed where built-in polymer strain sensors are adopted to measure the cable forces of bridge cables in the construction stage during their fabrication process. Based on the basic principles of polymer strain method, the cooperative deformation of intelligent steel wires and cables are utilized to realize the measurement of cable forces. The packaging characteristics of polymer strain sensor are explained, and static load test cable force measurement results are compared with the traditional magnetic flux sensor measurement method. The results show that the polymer strain parallel wire intelligent cable produced by the polymer strain cable force measurement technology has good sensing linearity and repeatability, and the identifiable cable force error of intelligent cable is -1. 38%, which has high accuracy and reliability. The measurement accuracy meets the requirements, and is suitable for rapid cable force monitoring in construction stage.

 The Yuechengling area , situated in the western segment of Nanling metallogenic belt , is recognized as one of the crucial Caledonian W-Sn mineralization prospective zones in South China due to its superior metal logenic geological conditions and dense distribution of mineralized occurrences.  A systematic investigation into its petrogenesis-metallogenic coupling mechanisms is indispensable for both theoretical research and achieving 
exploration breakthroughs.  This study focuses on Tongyoucun tin deposit and its ore-forming granites as key re
search subjects.  A systematic investigation is conducted , encompassing petrological analyses , zircon U-Pb and 
cassiterite U-Pb geochronology , whole-rock geochemical studies , and exploring their genetic relationships with 
tin mineralization .  Geochemical results reveal that the granites in mining area exhibit SiO2  and K2 O contents of
76. 00%-77 . 66% and 4. 78%-6 . 64% respectively , with an aluminum saturation index (ASI)  of 1. 16-1. 68
 and a differentiation index (DI)  of 88. 77-95. 10 , classifying them as the highly fractionated S-type granites 
within the strongly peraluminous high-K calc-alkaline  series.  The zircon  and  cassiterite  U -Pb  dating results 
show that the intrusion age of granite is 438. 0±10 . 0 Ma .  The tin-bearing greisen-type and fracture-zone vein
type cassiterite U-Pb ages in mining area are 429. 1±3 . 4 Ma and 413. 5±4 . 1 Ma , respectively.  These data in
dicate that both magmatic intrusion and tin mineralization events occurred during Late Caledonian period , with 
mineralization slightly postdating the granite emplacement.  The significant temporal gap between tin mineraliza
tion stages suggests the existence of two-stage tin mineralization events in Tongyoucun area , potentially linked to late-stage intrusions  related  to  tin  mineralization  at  depth.   Petrogeochemical  characteristics  indicate  that  the granites in mining area are formed during the post-collisional tectonic setting of orogenic compression-to-extension transition phase , representing a product of partial melting of ancient crust enriched in clay-rich metapelitic rocks.  Comprehensive studies reveal that Caledonian magmatic activity in Yuechengling area can be subdivided into six phases , corresponding to five W-Sn mineralization events.  Late-stage intrusions exhibit a specific metallogenic affinity with W-Sn mineralization