Based on the actual project, a three-dimensional simulation model is constructed to study the deformation and stress characteristics of the special-shaped soil-rock foundation pit excavation of the suspended pile. By adopting bar demolition method, a strength redundancy expression method based on the ultimate bearing capacity of the inner support is proposed, and two inner support importance evaluation indexes of the associated bar and the correlation coefficient are proposed. The findings indicate: (1) Deformation of special-shaped soil-rock foundation pit with the suspended pile mainly concentrates in the upper soil layers, the position of the positive angle and the middle of the longest side of the foundation pit., achieving a peak value of 17.02 mm. This deformation is linked to the geometric composition and stiffness distribution of the support system itself. Notably, the upper deformation of the supporting structure at the positive corner of the foundation pit is larger, and the influence range is about 2 times that at the negative corner; (2) The strength redundancy based on ultimate bearing capacity can comprehensively and quantitatively evaluate the redundancy of deep foundation pits, where the associated bar can pinpoint which component would be most affected after damage occurs, while the correlation coefficient can, to some extent, reflect critical components within support structures; (3) The redundancy of the inner support based on the ultimate bearing capacity is related to its own load and the arrangement of adjacent support bars. The minimum is 4.18. The associated bar are mainly concentrated in the adjacent bars. In the design of the correlation coefficient, should be optimized to decrease the correlation coefficient of the bar and improve the overall reliability of the support structure.

To investigate the multi-factor influence characteristics on the safety of tunnels subjected to sulfate attack, based on classical damage mechanics theory, the actual corrosion state of tunnel lining is considered as a combination of the uncorroded and fully corroded states. A numerical model is established to explore the effects of various factors on the safety of tunnels under sulfate attack and analyze their sensitivity. The results show that: (1) When tunnel lining is eroded by sulfates, the corrosion at the arch foot is more hazardous under the same conditions. (2) Increasing the initial strength and thickness of tunnel lining can improve the safety of tunnels before corrosion but have limited effects on improving safety after sulfate attack. (3) After corrosion occurs at a specific part of the tunnel lining, it mainly affects the safety of that corroded part while having minimal impact on the safety of other parts. (4) The sensitivity of various factors affecting the safety of tunnels under sulfate attack is in the following order: vertical load > initial lining thickness > initial lining strength > corrosion location > lateral stress coefficient > elastic resistance.

The frequent occurrence of microseisms in the reservoir area makes the muddy soft rock subject to cyclic shear dynamic action. Based on the fractional Nishihara model (FNM), the adhesive pot of Able is improved, and the constitutive model under the corresponding conditions is further obtained, which is verified by the cyclic shear test of the muddy soft rock sample. The research shows that: (1) the original FNM can be summed up as a special solution when the sinusoidal function (cyclic action) is zero in the proposed mode. (2) The model shows good applicability (R²∈ (0.96,0.98)), and the equation curve has the characteristics of “single and double turning points”, which can be found in the test. (3) The main influencing factor of the model is fractional order n, in which the stability condition n∈ (0,0.6), the failure condition n∈ (0.6,1.0). (4) With the increase of n, the shear modulus G and viscosity coefficient η decrease, which can better reflect the macroscopic phenomenon. (5) From the point of view of parameter disturbance, the irregular fluctuation of η with the increase of n in the previous literature is explained. The research results can provide theoretical reference for the long-term stability control of muddy soft rock slope under microseismic condition.

Based on the important literature databases at home and abroad, using literature measurement technology, this paper sorted out and improved the application status of tunnel type anchorages inside and outside the project, analyzed the characteristics of 30 tunnel type anchorages, such as construction location, application quantity, main span, axial length of anchorage plug body and surrounding rock properties, and speculated the future trend of tunnel anchorage construction. By means of literature statistics, the selection of tunnel type anchorage materials and structures is summarized, this paper investigates the publication of relevant Chinese and English papers on tunnel anchorage at home and abroad in the past 20 years, counts the literature source journals and Dissertations of tunnel anchorage, analyzes the publishing institutions of relevant papers, constructs a keyword co-occurrence network by using visualization technology, and sorts out the current research hotspots and emphases of tunnel anchorage. Based on the above research status of tunnel anchorage, this paper puts forward brief thoughts on the future research direction of tunnel anchorage, and believes that the application of tunnel anchorage will be more extensive, and more in-depth and comprehensive research on complex geology is also needed.

The shortage of urban land resources promotes the development of urban underground space, and a large number of foundation pit engineering are close to existing buildings, which brings great challenges to engineering construction. With the design conception of deep foundation pit has been changed from "strength control" to "deformation control", the protection of existing buildings has become a key problem in foundation pit engineering. To ensure the safety of buildings adjacent to deep foundation pit, the characteristics, sources, influencing factors and prediction methods of excavation-induced building deformation were summarized based on a large number of literatures, the major building protection measures at present were analyzed and sorted out based on the building deformation influence factors, and the adaptability of each measure was discussed, the comprehensive protection system of buildings adjacent to foundation pit was put forward combined with the foundation pit engineering investigation, building protection scheme design, foundation pit engineering construction and information construction monitoring, and provide reference and suggestions for related projects and researches.

Disturbance of the excavation surface caused by mud-water shield tunneling causes formation settlement. The main influencing factors are tunnel depth, mud weight, cutter opening ratio, propulsion speed, grouting pressure, soil properties (including cohesion and internal friction angle), and other engineering measures during construction. Based on the orthogonal test principle, the finite difference software FLAC3 D was used to study the global sensitivity of the influencing factors, and the tunneling parameters were also discussed. The results show that the internal friction angle has the most significant influence on the settlement index, followed by the propulsion speed, cohesion and mud weight, which are the main influencing factors. However, the influence of tunnel burial depth, cutter head opening ratio and grouting pressure on settlement is basically the same, which is a secondary influencing factor. In actual construction, the shield advancement speed and mud weight mainly control the ground settlement, while the mud weight and cutterhead opening ratio mainly affect the stability of the shield itself.

The sediment at the bottom of the pipe will change the pipe-rock contact state in long-distance rock pipe jacking engineering. Thus, the typical pipe-soil friction resistance calculation model used in the soil layer cannot reflect the dynamic contact state of the pipe-rock in long-distance pipe-rock jacking engineering. Combined with the typical pipe-rock contact model in long-distance rock pipe jacking, the main factors affecting the pipe friction resistance in the rock stratum are systematically analyzed, and the model’s applicability is verified by case analysis. The results show that the rock sediment, mud buoyancy, and pipe-rock friction coefficient are the main factors affecting the friction resistance of pipe in long-distance rock pipe jacking engineering. The suspension state, top point contact state, and full contact state can reflect the pipe-rock contact state in the initial jacking stage, normal jacking, and the extreme case of stuck pipe risk, respectively. The case study shows that the typical pipe-rock contact state proposed in this paper can reflect the friction resistance of long-distance rock pipe jacking at different stages of jacking, which has certain practicability and can provide a reference for similar projects.

To study the influences of the underpass tunnel proximity construction on the settlement of overlying suspension bridge tunnel anchor plug body, taking the Baishiyan tunnel Ⅰ under the tunnel anchorage of Lyuzhijiang bridge of Yuxi-Chuxiong Expressway as an example, model test and numerical analysis methods are used to analyze the deformation evolution characteristics of surrounding rock during the proximity construction, investigate the influence distance between plug body and tunnel and the burial depth of tunnel on the settlement of the plug body. The results show that: The settlement of plug body mainly occurs during the advance tunneling of the tunnel. The settlement of plug body and tunnel arch and disturbance area increase with the decrease of surrounding rock grade, the decrease of distance between plug body and tunnel and the increase of buried depth. The settlement of tunnel arch and the bottom settlement of plug body are the most sensitive to the change of tunnel buried depth, the least sensitive to the distance between plug body and tunnel. The change of the distance between plug body and tunnel has little effect on the settlement of tunnel arch, but has a greater effect on the settlement of plug body. The research results can provide important reference for the construction design and stability control of tunnel-type anchorage and underpass tunnel.

The rapid development of higher education has led to the increasingly tense development of land in colleges and universities, the shortage of accommodation and living space resources for teachers and students, and the development and utilization of underground space has gradually become the top priority in the construction of colleges and universities. This paper clarifies the motivation for the development of underground space in colleges and universities, collates the types and development modes of underground space, compiles the characteristics of underground space in colleges and universities both at home and abroad, and analyses it in the case of a college in Southwest China to predict the trend of the development of underground space in colleges and universities campuses. The study shows that: the development of underground space in colleges and universities needs to pay attention to the continuation of the era, emphasise the synergy of the landscape, strengthen the function of a single underground space, improve the depth of space, create an underground complex with the composite function of "learning-living-communicating" , strengthen the connection of multiple points, and take into account the synergy of the whole, and take the underground space of the college campus as a construction whole for planning and designing. A construction whole for planning and design, at the same time, pays attention to the combination of static and dynamic traffic in the development of underground space, to create intelligent underground space, in order to build intensive and high-quality underground space on college campuses. It is only through the construction of intensive and high-quality underground space on college campuses that we can add bricks and mortar to the progress and development of colleges and universities.

For the deep and long foundation pit affected by confined water, based on the foundation pit of the second expressway of Guangzhou New Bai-Yun international airport, the study on the bearing characteristics of diaphragm walls under different confined water levels was carried out. First, the monitoring data of the foundation pit under low-pressure water levels were analyzed. Then, simulation results from Midas GTS/NX were compared with the monitoring data, and the numerical method was also used to analyze the effect of 3 m, 6 m, 10 m confined water level after foundation pit excavation on the horizontal displacement along wall depth, the surface settlement and the axial forces of supporting. The results show that: (1) The horizontal displacement along wall depth significantly increases, and the maximum value is located near the bottom of the foundation pit. (2) The surface settlement appears to be a "grooving" shape, which increases first and then decreases, with the increase of outer distance from the diaphragm wall. The maximum settlement appears at 0.67 times the excavation depth of the foundation pit. As the confined water level rises, surface subsidence increases significantly. (3) The axial forces of the first supporting gradually decrease, and the axial forces of second and the third supporting significantly increase with the increase of confined water level. The research results provide the basis for the design and construction of the deep and long foundation pit affected by the high confined water level in coastal areas.