Project In Shanghai Research Articles

Prediction of Buildings’ Settlements Induced by Deep Foundation Pit Construction Based on LSTM-RA-ANN

In view of the shortcomings of existing methods for predicting the settlement of surrounding buildings caused by deep foundation pit construction, this study uses the monitoring data of a foundation pit project in Shanghai and divides the construction process of the pit into three working conditions, that is, enclosure construction, earthwork excavation, and basement support construction. The attention mechanism and residual update are integrated into the artificial neural network (ANN) model, and the root-mean-square error, average absolute error, and determination coefficient are used as the evaluation indices of the model. The artificial neural network prediction model LSTM-RA-ANN for building settlements in deep foundation pit construction was then established. The prediction performance of the model was also analysed under different working conditions, and the influences of the main factors (including the soil parameter, monitoring point location, activation function, hyperparameter, and input number) on the evaluation index was further explored. The results indicate that the performances of the established LSTM-RA-ANN model are closely related to the construction conditions, the predicted settlements agree well with the monitored ones in three working conditions with the greatest errors occurring at a later time of the working conditions, and the prediction accuracy of the great–small order corresponds to basement support, enclosure construction, and earthwork excavation respectively. The farther the monitoring point is from the edge of the pit, the better the model performance is. The activation function, initial learning rate, and maximum iteration batch have a great influence on the evaluation indices of the model, while the number of input points has little effect on the evaluation indices. These results may serve as a reference for the safe construction and normal operation of foundation pit engineering.

Development and Field Analysis of a Novel Servo Concrete Bracing System for Deep Foundation Pit Excavation

This study demonstrates the design and field implementation of an innovative servo concrete bracing system in foundation pit excavation. The bracing system comprises concrete struts, revised purlins, and hydraulic jacks, and its field performance is evaluated in a deep foundation pit project in Shanghai, China. The field measurements demonstrate that the servo bracing system effectively reduces the maximum lateral displacement of the retaining wall by up to 31%. Moreover, the servo jacks modify the wall’s flexural behavior by introducing local inflection points at certain depths and driving the displacement peak upward. Furthermore, the system’s performance varies with strut configuration, and servo forces influence not only the corresponding acting strut but also the adjacent struts’ behavior, implying that the monitoring scope should be expanded when applying the servo bracing system in actual engineering. This study provides a meaningful technical reference for future servo concrete bracing system applications in foundation pit engineering.

Large-diameter shield tunnel crossing closely to existing metro tunnels and a residential building: A case study

In urban regions with multiple existing underground structures, the construction of a new shield tunnel can elicit intricate responses in soil-structure interactions. Here, we present an exhaustive case study of a large-diameter shield tunnel project in Shanghai, focusing on the section that closely crosses an existing metro tunnel and a residential building. Based on the in-situ data, the settlements of the ground, metro tunnel, and residual building induced by the tunneling were analyzed, and the correlations of their deformation mechanisms were discussed. The results indicate that the presence of a metro tunnel effectively mitigates ground movement. The settlement near the existing metro tunnel is significantly smaller than that in relatively remote areas. Additional displacements, settlements followed by heaves, were observed in the existing metro tunnels. Tunneling-induced settlement was also observed in the residential building, reaching a maximum of 8.92 mm facing the crossing side. Settlement along the tunneling direction decreased notably for residential buildings, primarily owing to the reinforcing effect of the existing metro tunnel. These findings underscore the importance of considering the soil-structure interaction within multiple existing underground structures during close tunnel crossings.

Development and verification of shield thrust vector self-adaptive control technology in soft soil strata

To solve the difficulty in automatically obtaining an effective total thrust vector relative to the shield posture adjustment requirements during self-driving in soft soil strata, a shield thrust vector self-adaptive control technology for shield machines was proposed. Subsequently, a large-scale model platform was established to simulate the straight-line advancement of the testing shield machine under dynamic loads, and the feasibility of steady shield driving was verified. The test results showed that: the actual total thrust force exhibited the same variation characteristics according to load force, while a relatively fixed difference of 1000 kN between the two caused by the system friction was observed. A quick recovery after an abrupt jump of the shield speed was discovered once there was a sudden, significant change in the load. The actual resultant moment of total thrust force effectively responded to the load force, and the shield postures were maintained well. Further, the driving speed and the horizontal stroke difference were controlled in the ranges of ±3 mm/min and ±5 mm of each set values, respectively. Subsequently, this technology was applied to the Wusongkou Yangtze River Tunnel project in Shanghai, and the on-site test results verified its feasibility in actual soft soil strata. The shield speed remained stable as the actual thrust forces shared the same changing low of the target values, and a fixed difference between the two was maintained to ensure the movement of the shield machine. The variation curves of the actual steering angles in both the horizontal and vertical directions coincided with those of the target steering angles because the resultant horizontal and vertical moments of the thrust force effectively responded to each steering requirement, which was executed with high quality.

Numerical study on the influence of excavation slope on the structural behavior of ground penetrating shield tunnels

The ground penetrating shield technology (GPST) is a fast shield tunnelling method, wherein the shield is launched and received at the ground surface without constructing deep and large working shafts. With regard to the notable sloping excavation characteristics of the GPST, this study established a three-dimensional numerical model to analyze the impact of the excavation slope on the structural response of the tunnel lining based on the South Longshui Road Cross-river Tunnel project in Shanghai. The results indicate that the circumferential earth pressure acting on the lining is determined by both the buried depth and decomposition angle induced by the change in the excavation slope. The distribution of the earth pressure along the longitudinal direction may be affected by the excavation slope, and this subsequently affects convergence deformation of the tunnel. An increase in the excavation slope equalized the distributed force acting on the lining. In addition, the existence of circumferential joints exaggerates the impact of the excavation slope on the differential convergence between adjacent rings. A larger excavation slope resulted in a decrease in the proportion of convergence deformation caused by the longitudinal joints. These findings can provide important guidance for controlling the ovalization and dislocation behaviors of GPST.

Strategy and analysis of the deformation of subway tunnel caused by pre-dewatering under water-rich sand

Pre-dewatering is an essential step in deep foundation pits with water-rich sand, and its impact on the surrounding environment has attracted increasing attention. To study the impact of pre-dewatering on the tunnel, we selected a typical foundation pit project in Shanghai to conduct in situ pre-dewatering tests and comprehensively record the soil stress, horizontal displacement, and tunnel deformation around the foundation pit during pre-dewatering. The data showed a strong correlation between the displacement and stress changes in the surrounding soil and the locations of the pre-dewatered soil layers. Based on the changes in the water-earth pressure and displacement, the deformation mechanism of the adjacent subway tunnel caused by pre-dewatering before foundation pit excavation was analyzed. Combined with existing research results, strategies such as increasing the stiffness of the ground wall, improving the anti-deformation ability of the soil in the passive area, and on-demand dewatering were proposed, and the findings can be used as reference for similar projects.

From Hongkew Ghetto to Shanghai Ark: Rethinking representation in the (re)making of affective atmosphere during cultural regeneration

The “Shanghai Ark” is an urban regeneration project in Shanghai’s Hongkou (Hongkew) District, aiming to transform the built environment and cultural legacy of the former Jewish refugee community, Hongkew Ghetto, into the present Shanghai Ark neighbourhood, showcasing the city’s and the nation’s cosmopolitanism and generosity. This article re-evaluates the notion of representation and explores the interplay among top-down representations, emotional resonances, and atmospheric practices in urban spaces. By employing discourse analysis and ethnographic data, we examine perceptions and practices of various stakeholders, including officials, citywalk leaders, museum curators, residents, local visitors, and foreign visitors. The findings reveal that affective atmospheres emerge from the interweaving of top-down narratives, personal experiences and memories, and emotional resonances between bodies and material environment, as well as the emotional interactions among people. By reconsidering representations in shaping affective atmospheres, this study sheds light on the fluid and dynamic nature of cultural regeneration, offering a deeper understand of the multifaceted experiences and emotions that underlie urban development.

Diversified Filtering Mechanism for Evaluation Indicators of Urban Road Renewal Schemes

As global urban infrastructure renewal progresses, the urgent need for sustainability-driven urban renewal intensifies amidst resource scarcity and environmental concerns. Effective evaluation and decision making regarding urban road renewal schemes are prerequisites for their successful implementation. However, variation in the prioritization of indicators in project evaluations and the poor adaptability of existing frameworks hinder the quick assessment of diverse projects. To address this issue, this paper proposes a scheme evaluation framework with embedded renewal project features comprising four modules. Following the initial construction of a sustainability-driven evaluation system, an indicator-filtering mechanism combining the Latent Dirichlet Allocation (LDA) model with a text similarity algorithm is developed. The Entropy Weight-–TOPSIS method is then employed to derive the final optimal decision based on selected indicators. Applying the decision framework to the G15 Jialiu Widening and Reconstruction Project in Shanghai, China, indicators are reduced by 48.3%, with the optimal scheme decision consistent with the traditional Entropy Weight–TOPSIS method. The framework is robust and enhances decision efficiency, filling theoretical gaps in existing indicator-filtering mechanisms.

Protective effects of measures for railway subgrade adjacent to excavation of a parallel pit

The Hongqiao Airport–Pudong Airport urban railway construction project in Shanghai, includes a 156.1-m-long deep strip foundation pit that runs closely parallel to the subgrade of the Shanghai–Hangzhou High-speed Railway, operating at 300 km/h. With a maximum excavation depth of 25.5 m and a minimum distance of only 10.6 m between the outer edge of the pit and the subgrade slope foot, controlling the deformation of the foundation pit in soft soil and ensuring the safe operation of the adjacent high-speed railway present significant challenges. Various protective measures were implemented to mitigate subgrade deformation caused by pit excavation, including partition excavations, 1.5-m-thick diaphragm walls, a servo steel strut system, isolation piles between the subgrade and diaphragm walls, and water-resistant barriers. The foundation pit, soil, and railway subgrade deformations during excavation were measured and analysed. The results demonstrate that the protective measures limited lateral diaphragm wall deformation to within 0.14% of the excavation depth. The maximum horizontal and vertical displacements of the subgrade caused by excavation were 3.2 mm and 1.5 mm, respectively. As a result, trains safely passed through this section at a limited speed of 120 km/h. The findings presented provide useful reference information for similar projects.

Public Space Planning in Shanghai in the Post Pandemic Era Based on User Research

In the post epidemic era in China, the government is accelerating the modernization of urban governance. In this context, this article aims to use a quantitative research form of questionnaire surveys to collect the evaluation and expectations of Shanghai residents towards public spaces in Shanghai, and further analyze the data to provide directions for the development of Shanghai public space planning. After gathering the data, the research has found that the quantitative evaluation of public spaces in Shanghai by participants fluctuates very little, with user experience above average. Ordinary needs are basically met, but higher-level needs such as spiritual needs and self actualization are not met. Therefore, the renovation of public space is a must. After comprehensive analysis, the author suggests strengthening the renovation of old residential areas according to local conditions, adding health monitoring facilities, optimizing digital governance, increasing residents' participation, and increasing public welfare projects in Shanghai's future urban planning.

Advancing Shallow Tunnel Construction in Soft Ground: The Pipe-Umbrella Box Jacking Method

The development of modern cities has often led to increased traffic congestion and limited usable space. One effective solution to these problems is to construct roadway tunnels, which can expand urban space and alleviate traffic congestion. However, building large underpass tunnels in urban areas, especially in soft ground, presents technical challenges owing to its extensive environmental disturbance. The pipe-umbrella box jacking method offers a promising solution to these challenges as this method does not require breaking the ground from the surface or disrupting surface traffic. This study reviews the key techniques of the pipe-umbrella box jacking method for constructing large rectangular tunnels with small burial depths in soft ground. The study focuses on three main technical issues: pipe umbrella installation, soil face excavation, and box jacking control. Furthermore, two tunnel projects in Shanghai, China, are presented as case studies to showcase the construction challenges and countermeasures during box jacking tunneling with pipe-umbrella. Practical construction experience has revealed that the installation of the pipe umbrella before box jacking serves as an effective method of ground pre-support. However, its performance can be influenced by factors such as pipe installation deviation and inter-pipe connection design. Both open-face steel grid extrusion (SGE) shields and closed-face earth pressure balanced (EPB) shields can be used for soil excavation during box jacking, with different work modes resulting in distinct ground deformation patterns. Additionally, lubrication grouting has been found to effectively reduce friction resistance and affect vertical ground deformation. The study also examines the lessons learned from case studies and proposes optimization measures. This study can serve as a valuable reference for the tunneling industry, providing insights into the pipe-umbrella box jacking method and its application in constructing large rectangular tunnels in soft ground.

The efficacy of building information model in cost control of green buildings in Shanghai

With the rapid development of modern cities, green buildings have become an important way to reduce energy consumption and environmental impact. The focus of the industry has shifted towards controlling the costs associated with these green buildings. As a solution, Building Information Modelling (BIM), an integrated digital tool, has gained widespread usage in the cost control of green buildings, including in the city of Shanghai. As a centre city of China, Shanghai has both prospects and challenges in the field of green building cost control, it is extremely important to conduct this comprehensive study in Shanghai. Therefore, the primary objective of this study is to delve into the impact of BIM on the cost control of green buildings in Shanghai and unveil its effect during the implementation process of green building projects. To achieve this goal, the author used qualitative research and conducted in-depth interviews with engineers who have used BIM technology in various green building projects. The interviews explored the application of BIM and its effect on controlling costs. The findings of this study reveal that BIM has had a significantly positive impact on the cost control of green buildings in Shanghai. By implementing BIM, the efficiency of cost control has been enhanced throughout the entire life cycle of these environmentally friendly structures. This improvement stems from the ability of BIM to provide accurate and detailed information about the building's design, construction, and operation, enabling better decision-making and resource allocation. The implications of this study are twofold. First, it helps to theoretically understand the impact of BIM on green building cost control, especially in the context of Shanghai. This adds to the existing body of knowledge and furthers research in the field. Secondly, this study also fills the research gap of BIM in the cost control of green building projects in Shanghai.

Investigation on the Current Situation of the National Fitness Activity Brand Project in Shanghai

Through the investigation of the current situation of the national fitness activity brand project in Shanghai, this paper finds the problems in the organization and management, project content, brand value, explores the reasons, and puts forward scientific feasible suggestions on how to inherit, innovate and develop the national fitness brand project with Shanghai characteristics. For the masses to develop and innovate more abundant, more scientific fitness programs, for the sustainable development of the existing brand projects to provide ideas. Moreover, the formation of brand projects to a certain extent also sets an example for the development of national fitness sports in areas with relatively backward economic development level.

Shaking table test on the dynamic responses of shield tunnel in liquefiable stratum

Seismic liquefaction affects badly the safety of the underground structures. For the dynamic responses of the tunnel in liquefied watered sandy stratum in one of the rail transit projects in Shanghai, this paper proposes a tunnel-foundation shaking table model test and analyses the dynamic responses of electrolytic desaturation technology on surrounding soil, which provides some theoretical guidance for seismic designs of Shanghai rail transit projects. The test result shows that the excess pore pressure ratio of soil decreases gradually with the increase of buried depth; sand is easier to liquefy than silt so the tunnel liquefaction and uplift during the sandy section should be paid more attention to; electrolytic desaturation technology works significantly on improving the liquefaction resistance abilities of sand and silt which can effectively reduce the damage caused by tunnel uplift due to seismic liquefaction.

“The Leaves”: Redevelopment and Culture, West Guagfu Road Redevelopment Project in Shanghai

“The Leaves”: Redevelopment and Culture, West Guagfu Road Redevelopment Project in Shanghai

Life-Cycle Assessment of LEED-CI v4 Projects in Shanghai, China: A Case Study

The purpose of this study was to explore green office building certification strategies in Shanghai. The 45 LEED-CI v4 gold-certified office space projects were sorted by energy and atmosphere credit (EAc6, optimize energy performance) into two groups: 15 projects with the lowest EAc6 achievement (Group 1) and 15 projects with the highest EAc6 achievement (Group 2). To reach the gold certification level in Group 1, high achievement in EAc6 is associated with low achievement in two indoor environmental quality credits (EQc2, low-emitting materials, and EQc8, quality views), while in Group 2, low achievement in EAc6 is associated with high achievement in EQc2 and EQ8. For the life-cycle assessment (LCA), the functional unit was designated as follows: production (P) stage: production of building materials needed to ensure the requirements of EQc2 and EQc8 for 1 m2 of the building area; and operational energy (OE) stage: OE of 1 m2 of the building area over 50 years of the building’s lifetime. For the OE stage, two fuel source scenarios were used: 71.07% coal + 28.08% natural gas + 0.81% wind power (WP) + 0.04% photovoltaic (PV) (Scenario 1) and 50% WP + 50% PV (Scenario 2). The results of the LCA (P + OE) showed that under Scenario 1, the LEED certification strategy in Group 1 was greener than that in Group 2. When using Scenario 2, no differences were found between the two groups.

Community-dwelling older adults' experiences and perceptions of needs for home modification in Shanghai

Abstract Home environment is essential to older adults. While existing studies have investigated the positive implications of home modification strategies for older adults and proposed relevant policies and programmes, literature has remained relatively silent on how older adults perceive their needs for their home environment and its modification, especially during and after they go through home modification projects. This study investigated community-dwelling older adults' perceptions of needs for home modification in Shanghai. Informed by theories in environmental gerontology and tenets of awareness of age-related change, we conceptualised two intertwined, evolving processes of person–environment (P-E) interactions: older adults' interactions with their home environment, and the interactions between their perceptions of needs for home modification and the ageing process. Taking a qualitative approach, we interviewed community-dwelling older adults who were among the first to have received a pilot government-sponsored home modification project in Shanghai (N = 15). Our findings suggest that older adults' P-E dynamics evolved in response to their perception of their home environment and ageing process. Most participants initially were unaware of their underlying needs for home modification even when they had encountered challenges in their apartments. As the home modification project took place, participants gradually gained knowledge of their home environment and the following modification, which enabled them to better identify and articulate their needs to improve their daily living. After the project, participants' understandings of their home environments continued to evolve, expanding to their neighbourhood. This study informs policy and practice to focus on recognising the evolving aspects of older adults' needs in their home environment and better engaging older adults in the process of home modification.

Steel wire prestress analysis of large section jacking prestressed concrete cylinder pipe (JPCCP): Site experiment and numerical investigation

As one of the key factors of Jacking Prestressed Concrete Cylinder Pipe (JPCCP), stress condition of the steel wire has a significant influence on the safety and durability of the JPCCP. In this paper, the stress of the steel wire was analyzed in the process based on the in-situ test monitoring results and numerical investigation in the water conveyance project in Shanghai. According to test results, the stress losses during the entire process were ruled out and turned out to be quantized. The reduction rate of steel wire was quite high in the early stage of prestress, and gradually slowed down with the time. The relaxation of steel wire was the main influencing factor of prestress loss. The numerical model of JPCCP was established and verified by field test data. Mechanical properties and failure modes of JPCCP under high inner water pressure and under different prestress losses were analyzed. After the initial prestress of steel wire was reduced from 1048 MPa to 888 MPa, the prestress of concrete in pipe core was reduced by 15%, while the compressive stress of the outer concrete was reduced by 23%. The water pressure carrying capacity of the structure was reduced by 10%. The larger the prestress loss of the steel wire was, the earlier the concrete in the pipe core entered the plastic phase. The results indicate that the prestress loss of steel wire has a direct and prominent influence on the bearing capacity of the water pressure on JPCCP. To help tunnel designers incorporate the prestress requirement into their basis of design and structural analysis, an assessment method was also proposed.

Analyzing Stakeholder Relationships for Construction Land Reduction Projects in Shanghai, China

With the tightening of resource and environmental constraints and the increasing manifestation of land use conflicts, construction land reduction has become an important way to optimize land resource allocation and improve resource use efficiency. Taking the towns of Zhuqiao and Zhujiajiao in Shanghai as research subjects, this paper uses field research and case studies to summarize the main practices and completion of the land reduction and analyzes the interest preferences of different stakeholders. The results showed that the main stakeholders in the reduction of inefficient construction land in Shanghai include the municipal government, district government, town government, rural collective economic organizations, entrepreneurs, and villagers, which form a complex and intertwined interest relationship. The allocation of new construction land indexes, the supply of funds for the cost of reduction, and the resettlement method of the reduced enterprises are the key factors affecting the coordination of the relationship between the stakeholders. Protecting the economic interests of village collective organizations and villagers is an effective way to reduce the conflicts that occur between government and villagers, and between government and village collectives. The research outcomes will provide a theoretical reference for improving the existing reduction policies and function as a reference for the spatial development and control work in other regions of China.

Integrating heritage assets in large commercial complexes: de-contextualization and re-signification of memory in Shanghai

Since early this century, multiple large-scale commercial projects in Shanghai and other Chinese cities incorporate heritage assets for the creation of new identities after de-contextualisation trough demolition of complete city blocks. This tabula rasa approach resulted in a discontinuity of the meaning and use that local communities gave to these heritage buildings and a re-appropriation by new users in a context of consumerism. This paper studies two cases in Shanghai city center: Jing An Kerry Centre and Greenland Bund Centre, where heritage buildings related to the memories of Communism, trading societies and Christianity are incorporated into high-density high-end commercial redevelopment. As we argue, the study of heritage conservation methods and urban design approaches reveals profound discontinuities in the position and meaning of heritage assets, which respond to important political and economic performance requirements. This paper puts forward two main arguments. Firstly, that the choice of heritage conservation methods and design approaches aligns with the new official narrative of the desired image of Shanghai as a prosperous global city rooted in Communism. Secondly, that the de-contextualisation of heritage assets within a new corporate urban context motivates specific heritage-related landscape, urban and architectural design responses, that contribute to their re-contextualisation in a new sanitized urban environment.