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Most of the time, geotechnical engineering interventions require solutions that necessarily aim for better use of the available space. Many slope stabilization techniques were developed following that assumption, and one of the most applied procedures in Brazil is the soil nailing reinforcement. These engineering techniques are constantly improving. Consequently, a continuous study of the design and behavior of soil nails is important. The technique of vertical nails reinforcement in soil nailing is recent in the Brazilian scenario. Nowadays, some constructors started to use them near the slope face when stabilizing huge excavations. This paper aims to verify the vertical nails’ efficiency in reducing horizontal displacements. We present three numerical modeling analyses using the finite elements method (FEM). The proposed model is a soil nailing of approximately 18m high in a homogeneous subsoil in São Paulo city. Comparing situations with and without vertical nails, as if an inclined face (slope), the results showed that adding those nails could reduce horizontal displacements.

Mining-induced deformations of the ground surface and within the rock mass may pose danger not only for surface constructions but also for underground objects (e.g., tunnels, underground storages, garages), diverse types of pipelines, electric cables, etc. For a proper evaluation of hazard for surface and underground objects, such parameters as horizontal displacement and horizontal deformations, especially their maximum values, are of crucial importance. The paper is an attempt at a critical review of hitherto accomplished studies and state of the art of predicting horizontal displacement , in particular the coefficient , whose value allows determination of the value of maximum displacement if the value of maximum slope is known, or the value of maximum deformation if the value of maximum trough slope is recognized. Since the geodesic observations of fully developed subsidence troughs suggest that the value of the coefficient depends on the depth , radius of main influences range and properties of overburden rock, in particular the occurrence of sub-eras Paleogene and Neogene layers (old name: Quaternary and Tertiary) with low strength parameters, therefore a formula is provided in the present paper allowing for the estimation of the influence of those factors on the value of coefficient

Taking the construction project of a new bridge pile foundation above an in-service subway in Xi’an as an example, considering the influence of horizontal symmetrical construction of pile foundation hole forming on the deformation of different sections of asymmetric tunnels, a three-dimensional finite element geometric model of pile-tunnel-soil is established based on ABAQUS software. Through the numerical simulation analysis of the structural deformation behavior of the in-service subway tunnel under the two construction stages of pile foundation hole forming and concrete pouring, the horizontal and vertical deformation laws of the key points of the in-service subway tunnel caused by the construction of the adjacent new pile foundation are analyzed from different angles.The calculation results show that: the deformation of the interval tunnel is mainly caused by vertical displacement, resulting in overall settlement of the tunnel. However, the settlement value is within a controllable range and does not affect the normal operation of the in-service subway tunnel. The concrete pouring stage has a greater impact on subway tunnels. The research work has important reference value for the reasonable safety monitoring and control of similar construction projects.

The article presents an analysis of the horizontal land surface displacements taking place as an effect of coal exploitation on the Girondelle 5 seam in the Friedrich Heinrich-Rheinland mine in Germany. The paper presents changes in displacement vectors measured on the surface following the progress of the exploitation face and an analysis of horizontal displacement measurements assuming that their magnitude is proportional to the profile of subsidence trough slope. Then, the values of horizontal displacement coefficient B are assessed for selected longitudinal and transversal calculation cross-sections of longwall No. 537.

This study focuses on the transportation of non-uniform cuttings in the drilling process of long-reach horizontal wells, conducting a comprehensive theoretical analysis and experimental investigation. Initially, a computational model was established to analyze the influence of cuttings size distribution, fluid dynamics parameters, and wellbore geometry on the transport of non-uniform cuttings. The research elucidates the non-linear relationship between cuttings transport efficiency and parameters such as flow velocity, well inclination, and drill pipe rotation rate in long-reach horizontal wells. It also identifies the existence of a critical flow velocity, beyond which drilling fluid can effectively carry cuttings, preventing their accumulation at the well bottom, and ensuring wellbore cleanliness. Additionally, the paper proposes optimization strategies for wellbore cleaning based on the transport behavior of cuttings, including adjustments to fluid flow velocity and optimization of well inclination, aimed at enhancing drilling efficiency and reducing drilling costs. The findings provide theoretical guidance for cuttings management in long-reach horizontal wells, contributing to improved safety and cost-effectiveness in drilling operations. They hold significant value for advancing the technology of drilling horizontal wells under complex geological conditions.

The offshore wind energy (OWE) pile foundation is mainly a large diameter open-ended single pile in shallow water, which has to bear long-term horizontal cyclic loads such as wind and waves during OWE project lifetime. Under the complex cyclic loads, the stress and displacement fields of the pile-soil system change continuously, which affects the dynamic characteristics of the pile foundation. Within the service life of the pile foundation, the pile-soil system has irreversible cumulative deformation, which further causes damage to the whole structure. Therefore, it is important to examine the overall dynamic characteristics of wind power foundation under high cycle. In this paper, in the dry sand foundation, taking the Burbo Bank 3.6 MW offshore turbine-foundation structure as the prototype, the horizontal cyclic loading model tests of the wind power pile foundation with the scale of 1:50 were carried out. Considering the factors such as loading frequency and cyclic load ratio, the horizontal dynamic characteristics of the whole OWE pile foundation are studied. The comparison results between the maximum bending moment of pile and the fitting formula are discussed. In conclusion, moment of OWE pile shaft is corresponding to the loading frequency (f = 9 HZ) and loading cycles by fitting formulas. The fatigue damage of the OWE pile does not occurs with low frequencies in high cycles.

Deep displacement monitoring of rock and soil mass is the focus of current geological hazard research. In the previous works, we proposed a geophysical deep displacement characteristic information detection method by implanting magneto-electric sensing arrays in boreholes, and preliminarily designed the sensor prototype and algorithm of deep displacement three-dimensional (3D) measurement. On this basis, we optimized the structure of the sensing unit through 3D printing and other technologies, and improved the shape and material parameters of the permanent magnet after extensive experiments. Through in-depth analysis of the experimental data, based on the data query algorithm and the polynomial least square curve fitting theory, a new mathematical model for 3D measurement of deep displacement has been proposed. By virtue of it, the output values of mutual inductance voltage, Hall voltage and tilt measuring voltage measured by the sensing units can be converted into the variations of relative horizontal displacement, vertical displacement and axial tilt angle between any two adjacent sensing units in real time, and the measuring errors of horizontal and vertical displacement are tested to be 0–1.5 mm. The combination of structural optimization and measurement method upgrading extends the measurement range of the sensing unit from 0–30 mm to 0–50 mm. It shows that our revised deep displacement 3D measuring sensor can better meet the needs of high-precision monitoring at the initial stage of rock and soil deformation and large deformation monitoring at the rapid change and imminent-sliding stage.

The difficulty in predicting the horizontal displacement of the support pile top in ultra-deep foundation pits within muddy formations, combined with insufficient consideration of parameter discretization characteristics in existing methods, motivates this study. Taking the Songtao Street Station project of Suzhou Metro Line 8 as a case study, this paper classifies the soil layers and implements corresponding support technologies. First, based on the engineering geological and hydrological conditions, the discrete values of earth pressure, the discrete combination of support structure thickness, and the discrete gradient of the lateral earth pressure coefficient are selected as core discrete variables. Second, a numerical model is constructed using FLAC3D software, and the soil-structure interaction is simplified via the elastic foundation beam method. The deflection differential equation of the support structure is derived to verify the accuracy of the elastic modulus conversion formula and the earth pressure calculation method. Subsequently, the influence of key parameters, such as the lateral earth pressure coefficient and the cohesion of silty clay, on displacement is analyzed. Finally, the reliability of the model is verified using on-site monitoring data from 12 monitoring points throughout the entire construction period. The results indicate that the displacement error between numerical simulation and actual measurement is ≤ 3.3%. When the lateral earth pressure coefficient is 1.0, the horizontal displacement of the pile top is minimized. The safety factor of uniformly thick shotcrete support is 1.8–2.9 times higher than that of non-uniform schemes. Significant creep characteristics are observed during the excavation and sealing of ultra-deep foundation pits in muddy formations. This study provides a quantitative basis for the discrete selection of support parameters for ultra-deep foundation pits in similar silty formations and improves the accuracy of displacement prediction.

This paper presents a novel method for extracting the land vertical displacement rates (VDRs) in Shanghai (China) using the multi-platform SAR images collected between 2009 and 2010, i.e., the ascending/descending COSMO-SkyMed (CSK) X-band images and the descending TerraSAR (TSX) X-band images. Different from the conventional approach the proposed method estimates the VDRs by multi-temporal interferometric SAR processing (i.e., temporarily coherent point InSAR, TCPInSAR) and the localized least square (LS) solution, through which the horizontal displacement rates (HDRs) can be also derived as the by-product. The three types of displacement rates in the radar line of sight (LOS) are first estimated by TCPInSAR with use of the ascending/descending CSK and descending TSX data. Both the VDRs and HDRs are then estimated by a localized LS method on the basis of the three types of LOS displacement rates derived by TCPInSAR. For comparison purposes, the VDRs for the single-platform SAR data are also obtained through dividing the LOS displacement rates by the cosine of the radar incidence angle. The analysis with the aid of GPS data shows the horizontal motion due to the geological settings in Shanghai cannot be ignored, and the VDRs derived from the single-platform data are not accurate and reliable without taking into account the horizontal motion. The experimental results indicate the TCPInSAR-LS method can be used to efficiently improve the accuracy in the VDRs by integrating the multi-platform SAR data and considering both horizontal and vertical motion, thus overcoming the disadvantages in the conventional approach. The improved VDRs in Shanghai range between −22.8 and 9.6 mm/year, while the relative east-west motion rates range between −7.2 and 6.2 mm/year, and the relative north–south motion is subtle and can be ignored. Analysis of the improved VDRs shows that a slightly uplifting area of about 70 km2 appears in the west downtown of Shanghai, and a subsiding bowl appears in the Hongkou District of Shanghai. The validation indicates that the uplifting trend can be ascribed to the measures conducted by the Shanghai municipal government, i.e., decreasing the groundwater pumping volume and increasing the groundwater recharge volume.

Horizontal displacement of hydropower dams is a typical nonlinear time-varying behavior that is difficult to forecast with high accuracy. This paper proposes a novel hybrid artificial intelligent approach, namely swarm optimized neural fuzzy inference system (SONFIS), for modeling and forecasting of the horizontal displacement of hydropower dams. In the proposed model, neural fuzzy inference system is used to create a regression model whereas Particle swarm optimization is employed to search the best parameters for the model. In this work, time series monitoring data (horizontal displacement, air temperature, upstream reservoir water level, and dam aging) measured for 11 years (1999–2010) of the Hoa Binh hydropower dam were selected as a case study. The data were then split into a ratio of 70:30 for developing and validating the hybrid model. The performance of the resulting model was assessed using RMSE, MAE, and R 2 . Experimental results show that the proposed SONFIS model performed well on both the training and validation datasets. The results were then compared with those derived from current state-of-the-art benchmark methods using the same data, such as support vector regression, multilayer perceptron neural networks, Gaussian processes, and Random forests. In addition, results from a Different evolution-based neural fuzzy model are included. Since the performance of the SONFIS model outperforms these benchmark models with the monitoring data at hand, the proposed model, therefore, is a promising tool for modeling horizontal displacement of hydropower dams.