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Illustration of slurry shield: (a) slurry shield (diameter: 15.43 m); (b) Shanghai Changjiang Under River Tunnel Project, which was constructed by the same shield; from Herrenknecht website (http://www.herrenknecht.com).
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![Fig. 3. Illustration of soil profile [36].](profile/Chao-Liu-26/publication/260994981/figure/fig3/AS:553894099025920@1509070052559/Illustration-of-soil-profile-36_Q320.jpg)
The study investigates the disturbance to piles and pile groups caused by multiple nearby drives of a large diameter slurry shield-driven tunnelling machine in Shanghai. The minimum distance between the slurry shield tunnel (with diameter D = 15.43 m) and the adjacent pile groups of Metro Line 3 and Yixian Elevated Road is 1 m. The nonlinear finite...
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... large diameter slurry shield machine (D = 15.43 m) manufac- tured by Herrenknecht AG was adopted (Fig. 2). The shield was launched initially on the east bank of the Huangpu River and dri- ven approaching the working shaft on the west bank. After being received on the west bank, the shield was disassembled and reas- sembled in two months and launched in the opposite direction to the shaft on the other side of the river. During tunnelling ...
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... on the description in Section 2.5, an FE model which in- cludes both the Yixian Elevated Road and Metro Line 3 is pro- posed in the study. Fig. 20 illustrates the FE model developed for analysing the tunnel crossing section where measurements are obtained. The soil properties employed are shown in Table 1. Seven settlement markers were fixed on the pile caps of Metro Line 3 as shown in Fig. 20(c). Unfortunately, no field data are available for the Yixian Elevated Road. ...
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... model which in- cludes both the Yixian Elevated Road and Metro Line 3 is pro- posed in the study. Fig. 20 illustrates the FE model developed for analysing the tunnel crossing section where measurements are obtained. The soil properties employed are shown in Table 1. Seven settlement markers were fixed on the pile caps of Metro Line 3 as shown in Fig. 20(c). Unfortunately, no field data are available for the Yixian Elevated Road. Consequently, only the movements of Metro Line 3 pile groups are analysed in the study. The pile groups of Metro Line 3 were embedded well below the tunnel invert level. This situation was different from the experi- mental section in which the depths of the pile ...
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... typical step-by-step modelling technique was adopted in the FE simulation. The excavation directions are shown in Fig. 20(a). The south bound tunnel was excavated first (excava- tion steps 0-80). After the shield arrived at the working shaft at West Shanghai, a transient FE analysis with a total time of 90 days was conducted to simulate the consolidation process during the disassembly and assembly of the shield machine (excavation steps 81-84). After the ...
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... advancing speed is 7 rings/day (14 m/day). The working shaft is not in- cluded in the model so as to simplify the FE simulation process. The element types adopted for the soil, tunnel linings, shield ma- chine, and viaduct pile foundations are consistent with the FE models of experimental sections. Dimensions of the FE model are illustrated in Fig. ...
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... (4.9 mm before grouting; 5.7 mm after grouting), respectively. It can be deduced that although PII008 was closer to the tunnel, its response to synchro- nous grouting was not as significant as PII007. Nevertheless, from the perspective of the whole tunnelling process, pile group PII008 was more impacted than PII007 (i.e., larger heave in PII008). Fig. 22 illustrates the vertical movement of another two pile groups (PII009 and PII010, Fig. 6(c)) during south bound tunnelling. Since these two pile groups were not directly adjacent to the shield during south bound tunnelling, the vertical displacements were relatively small compared with PII007 and PII008. According to the field data, the ...
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... is noteworthy that Fig. 22(a) shows differences between the measurement points QZ3 and QZ4 in the field data. This indicated an incline occurred in the pile cap during tunnelling. In corre- sponding FE results, an incline in the opposite direction is indicated. This difference is probably caused by the simplification of the FE model in which the upper structure of ...
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... 23 and 24 illustrate the vertical displacement of the four pile caps during north bound tunnelling. It can be concluded that a closer distance to the tunnel can result in greater heave of the pile groups. For PII009 (Fig. 23(a)) which is located at a 1.677 m clearance from the tunnel, the two measurement points experi- enced settlement before the tunnel face arrival. However, during passage of the shield, the pile cap started heaving with a good agreement between field data and FEA results. Similarly, the other directly influenced pile group PII010 (Fig. ...
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... PII009 (Fig. 23(a)) which is located at a 1.677 m clearance from the tunnel, the two measurement points experi- enced settlement before the tunnel face arrival. However, during passage of the shield, the pile cap started heaving with a good agreement between field data and FEA results. Similarly, the other directly influenced pile group PII010 (Fig. 23(b)) whose clearance was 5.675 m also experienced the same variation of vertical move- ment during the north bound tunnel construction. However, due to the large clearance of PII010 (5.675 m in Fig. 6(c)), its vertical dis- placement was smaller than that of PII009 both in measured field data and FEA results. It also can be observed that ...
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... PII007 and PII008, similar development trends of vertical displacement occurred, but with smaller magnitudes. The FEA re- sults for PII007 show good agreement with field observation before the pile cap started heaving during shield passage (Fig. 24(a)). The field data of PII008 (Fig. 24(b)) indicate a considerable incline be- fore the tail passage, and this incline was relatively large compared with the other pile groups. The settlement of the four pile groups occurred at the beginning of shield passage. This was probably caused by the insufficient slurry pressure as well as the ...
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... PII007 and PII008, similar development trends of vertical displacement occurred, but with smaller magnitudes. The FEA re- sults for PII007 show good agreement with field observation before the pile cap started heaving during shield passage (Fig. 24(a)). The field data of PII008 (Fig. 24(b)) indicate a considerable incline be- fore the tail passage, and this incline was relatively large compared with the other pile groups. The settlement of the four pile groups occurred at the beginning of shield passage. This was probably caused by the insufficient slurry pressure as well as the impact of shield ...
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... the practical tunnel shield crossing of the two bridges, the field data were far from sufficient. Nevertheless, the FEA results can still provide more detail about the variations of the pile group settlement during the multiple tunnelling process. According to the FEA results, the two pile groups (PII007 and PII008, Fig. 24) experienced settlement before the tunnel face was two tunnel diameters (2D = 31 m) from Metro Line 3 during the south bound tunnelling process (Fig. 21). However, the vertical displacement of PII009 and PII010 showed increasing heave during the whole tunnelling process along the north bound direction (Fig. 23). This difference was ...
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... two pile groups (PII007 and PII008, Fig. 24) experienced settlement before the tunnel face was two tunnel diameters (2D = 31 m) from Metro Line 3 during the south bound tunnelling process (Fig. 21). However, the vertical displacement of PII009 and PII010 showed increasing heave during the whole tunnelling process along the north bound direction (Fig. 23). This difference was probably caused by the existence of the Yixian Ele- vated Road. In tunnelling along the south bound direction, pile groups of the Yixian Elevated Road experienced settlement which resulted in the settlement of its surrounding soil. Because the Yix- ian Elevated Road was the first one to be influenced during the ...
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... bound tunnelling; PII009 and PII010 for north bound tunnelling) showed different trends. The PII008 and PII007 experienced con- siderable settlement (Fig. 21) before the arrival of the tunnel face during the south bound tunnel advancement. On the contrary, PII009 and PII010 did not experience settlement during the north bound tunnel advancement (Fig. 23), but only ...
Citations
... In the field of architecture, these advances have had a significant impact on architectural design, construction, and renovation [13][14][15][16]. By simulating and analyzing the response of building structures under different conditions, engineers can better evaluate the performance and safety of the structure and take measures to optimize the design and improve the safety of the structure [16][17][18]. Using advanced finite element analysis software, construction engineers can simulate the response of structures under different earthquake, wind, and temperature to predict the results and optimize their design. ...
This article investigated the construction conditions of the pile foundation in the Wuxing section of the “Shanghai Suzhou Huzhou” railway bridge project. To test the reliability of large diameter connectors, it has established a finite element model with ABAQUS software for numerical simulation. Based on on-site tests, the reliability of the connection between the pipe pile and the cover steel was studied. According to the simulation results, when the load is P= 900 kN, the displacements of A2 and A3 steel pipe piles are 55.8 mm and 60.1 mm, respectively. The load-displacement relationship shows a high-order curve distribution. According to the results of on-site experiments, the displacements are 77.9 mm and 60.2 mm, respectively. The load-displacement relationship is linear. The results for the simulation and on-site testing are consistent. This study provides a basis to the research on the reliability of the connection between large-diameter steel pipe piles.
... In terms of model experiments, He et al. [7] conducted physical model tests to study the mechanical response of pile groups with different spacings and the blocking effect of pile groups. In the field of numerical computation, scholars have studied the disturbance characteristics of adjacent single piles and pile groups during shield construction, including different geological conditions such as complex strata, river crossings, static loads, dynamic loads, different pile foundation parameters, and different distances between piles and tunnels [8,9,10,11,12,13,14]. The construction of underground transportation systems often involves double or multiple tunnels. ...
By relying on the foundation engineering of pile foundations for the Chengdu Metro Line 27 shield tunneling through interchange bridges, three-dimensional numerical simulation results are used to verify field measurements. This study investigates the horizontal displacement, vertical displacement, and stress characteristics of the pile foundation during shield tunneling considering the coupling effect of seepage stress. Additionally, protective measures and reinforcement effects for pile foundations near the tunnel are discussed. Results show that the deformation caused by shield tunneling in gravel strata mainly affects piles within 10 ring widths before and after the piles. During right-side excavation, the bending moment of the pile body exhibits an inverted “S” distribution, while during left-side excavation, it is symmetrically distributed, with the maximum bending moment and axial force occurring at the same buried depth as the tunnel crown. Vertical displacement of the pile body is divided by the horizontal position at the top of the tunnel, with upper pile settlement and lower pile uplift, reaching maximum at the pile top. Horizontal displacement of the pile body shows an “arch” distribution, with stress concentration near the tunnel, indicating an overall trend of the pile foundation moving away from the tunnel. Based on the mechanical response of the pile foundation, control measures such as ground pregrouting with sleeve valve pipes and semicircular grouting inside the tunnel are proposed. Optimized reinforcement parameters are obtained through three-dimensional numerical simulation, resulting in an 80% reduction in horizontal displacement, an 80.5% reduction in vertical displacement, a 70% reduction in pile axial force, and a 67% reduction in pile bending moment under the optimal reinforcement conditions. The research provides important theoretical basis for revealing the impact laws of shield tunneling through pile foundations in gravel strata and for controlling bridge pile deformation.
... Table 1 lists the soil properties and constitutive parameters of the different layers used in the FEA. The elements in each layer are assigned the corresponding soil properties, and the complex heterogeneous stratum has been idealized into six homogeneous layers [25,26]. Toward that end, the Acta Geotechnica soil layers with similar characteristics were merged into homogeneous layers and the soil layers with negligible volumetric contribution were ignored, such as the layer À 2 (plain fill) and layer`3 (mucky silty clay) as shown in The parts of the numerical models are solely composed of solid hexahedral (brick) finite elements [27]. ...
In this paper, the deformation response of the stratum in the vicinity of a tunnel is investigated based on a case study in Tianjin. A method to predict the surface settlement in the case of double-track curvature shield tunneling is also proposed. The research methodology consists of analytical calculations, finite element analysis as well as field monitoring. Straight shield tunneling and curvature shield tunneling are modeled, each with a single-track shield and a double-track shield, and their operational parameters are compared. The influence of overcutting and existing tunnel on ground movement is also discussed. The salient observations from the series of analyses are as follows: (a) The maximum settlement induced by curvature shield tunneling is much greater than that induced by straight shield tunneling, while the existing tunnel has little impact on stratum settlement in contrast, (b) the proposed method of predicting the surface settlement induced by double-track curvature shield tunneling fits well with the field-monitored data in the Tianjin case study, and (c) the location of the maximum ground settlement is deviated by the overcutting phenomenon, whereas the settlement of the soil above the excavated tunnel is reduced due to the presence of the existing tunnel.
... Owing to the rapid urbanization of China and exploration of underground space in many cities (Chiang and Lee, 2007;Lu et al., 2020;Lueprasert et al., 2017;Ng et al., 2013;Simic-Silva et al., 2020;Soomro et al., 2015;Soomro et al., 2017;Yoo, 2013). The construction of subway tunnels will inevitably affect the demand for safety and stability of adjacent building foundation structures along urban metro lines (Gokuldas et al., 2020;Liu et al., 2014;Ng and Lu, 2014;Sohaei et al., 2020;Wei, 2023;Wei et al., 2022). Fig. 1 shows illustrations of the excavation tunnel and existing pile models. ...
Tunnel excavation in short distance will change the physical equilibrium stress field of stratum and cause adverse effects on adjacent existing pile. A simplified analytical solution to calculate the horizontal displacement of existing pile under the influence of unloading in adjacent tunnel excavation is presented. First, consider that the existing pile is a Euler-Bernoulli beam resting on the Pasternak foundation model. Then, the free ground settlement of existing pile caused by a modified Loganathan’s formula during shield tunnel excavation is considered. The differential equation of lateral displacement of existing pile is established by combining the displacement coupling condition of tunnel-soil-pile foundation. Finally, the analytical solution of lateral displacement of pile caused by adjacent tunnelling is obtained by finite difference method. The reliability of the analytical solution is validated by comparing with boundary element program, finite element simulation and field measurement. Then, results of different factors such as tunnel buried depth, tunnel excavation radius, clearance distance between tunnel and pile on existing pile is analyzed. Through parameter analysis, the theoretical formula of maximum horizontal displacement of pile caused by tunnel excavation is put forward. The research content can provide theoretical verification for the investigation on the influence of adjacent tunnelling on deformation of existing pile.
... Given the convenience and cost-effectiveness of the finite element method, numerous studies on the impacts of tunnel excavation on nearby existing pile foundations were conducted through this method [15,16]. This encompassed an exploration of various aspects, mainly including the influence of diverse geometric parameters [17], the impact of different construction parameters [18,19], the distinct effects of tunnel excavation on individual pile and group piles [20,21], and the varied effects of the construction sequence of doubletrack tunnels on pile foundations [22,23]. ...
According to the design specifications, the construction of extended piles involves traversing the tunnel’s upper region and extending to the underlying rock layer. To address this challenge, a subterranean transfer structure spanning multiple subway tunnels was proposed. Deliberating on the function of piles in the transfer structure as springs with axial and bending stiffness, and taking into account the force balance and deformation coordination conditions of beams and plates within the transfer structure, we established a simplified mechanical model that incorporates soil stratification by combining it with the Winkler elastic foundation beam model. The resolved established simplified mechanical model employed finite difference technology and the Newton-Simpson method, elucidating the mechanical mechanism of the transfer structure. The research findings suggest that the load carried by the upper structural columns can be transferred to the pile foundation beneath the beams through the transfer structure, subsequently reaching the deep soil layer and ensuring minimal impact on adjacent tunnels. The established simplified analysis method can be used for stress analysis of the transfer structure, concurrently considering soil stratification, pile foundation behavior, and plate action. The pile length, pile section size, and beam section size within the transfer structure should account for the characteristics of the upper load, ensuring an even distribution of the beam bending moment.
... On the other hand, using such high values of stiffness will also result in zone-overlapping errors during the calculation of the FD code, causing more complexities for the numerical integration. Although various researchers have used the conventional method of using the interface element in tunneling cases taking into account the sensitivity of the interface elements as well as verification of the interactions to get more reliable results (Fargnoli et al. 2013;Liu et al. 2014;Pang et al. 2005;Kasper and Meschke 2004), a number of researchers have used non-interface models (also called the "fictitious-shield" models) to avoid further complexities and to omit the uncertainties of such method (Ring and Comulada 2018;Jin et al. 2022;Liu et al. 2021;Mohammadzamani et al. 2023;Do et al. 2014;Mollon et al. 2009;Shen 2009;Zhang et al. 2016;Epel et al. 2021;Le et al. 2022). ...
One of the most substantial issues faced during the excavation of deep tunnels in weak geomechanical conditions is the squeezing phenomenon. Thrust force determination of the shielded tunnel boring machines (TBMs) in such conditions is of utmost importance. In this study, the Beheshtabad water conveyance tunnel in the central part of Iran is chosen as a case study. The creep parameters of Burger’s model (CVISC) are determined using laboratory creep tests on samples from the 19th zone of the tunnel with high squeezing potential, and the results were verified using finite difference simulation of the test. A new approach based on the convergence-confinement method is used to calculate the required thrust force of a double-shield TBM using radial displacement profile (RDP) and ground reaction curve (GRC). The effect of various penetration rates on thrust reduction as well as the impact of different over-boring values and standstill times has been evaluated. The results show that in small values of over-boring, due to high overburden pressure and weak geomechanical conditions, required thrust values are incredibly high and the increment of penetration rate is almost ineffective, and the negative effect of standstill time is more evident. Higher penetration rates have a significant impact on thrust reduction in all cases which is a noticeable factor to avoid TBM jamming under squeezing conditions. In higher over-boring values, thrust reduction is positively conducted through increasing the penetration rate and the negative effect of standstill time is minor.
... Past analyses have mainly focused on investigating the interaction between two horizontally aligned tunnels through various research methodologies. These include physical tests [1][2], empirical/ field measurements [3][4][5][6], analytical methods [7][8], and numerical analyses [9][10][11][12]. ...
In any metropolitan area, underground tunnels play an important and essential part in a mass rapid transportation system. If the soil is poor, where the tunnel construction will be carried out, the possibility of constructing a single tunnel with a large diameter capable of accommodating two-way train traffic becomes very low. Due to this problem, constructing two parallel tunnels aligned horizontally or vertically becomes more important for the given site condition. A significant earthquake could result in the possible loss of human life as well as significant infrastructural damage to underground tunnels. Significant financial losses may arise from this, particularly considering the time needed to restore the tunnel’s functionality. It is crucial to lessen the potential risk involved and the consequences of damage to decrease the potential loss of serviceability of underground structures. Therefore, it is crucial to comprehend how underground tunnels respond to earthquakes and determine whether they sustain any harm. In this paper, three-dimensional finite element analysis of underground twin tunnels has been performed using PLAXIS 3D software. This study investigated the effect of soil structure interaction on the seismic response of twin tunnels. The effect of clear spacing between the tunnel and the relative position of the tunnel has also been considered in the present analysis. A typical section of the Delhi Metro underground tunnel has been considered for the analysis. Chamoli Earthquake,1999 has been taken for the seismic analysis of twin tunnels. The analysis revealed the fact that the clear spacing between tunnels is an important parameter that controls the distribution of stresses, displacements, and forces in the tunnel.
... Lee studied the influence of advancing open-face tunnel excavation on existing piles through the use of a three-dimensional elastoplastic-coupled consolidation numerical method, suggested the influence zone near the excavation face, and obtained a relative subsurface settlement, the side shear stresses, and pore pressure on the foundation [23]. Liu studied the effects of slurry pressure, grouting pressure, grouting material hardening, and soil-pile interaction on the movement of pile groups induced by the shield-construction process via the nonlinear finite-element method [24]. Based on the three-dimensional coupled-consolidation finite-element method, Soomro investigated the load-transfer mechanism between piles in a group and analyzed the settlement and tilt of the pile group related to the adjacent shield-tunnel excavation [25]. ...
This paper studies the problem of shield tunnels laterally passing through piles based on in situ tests and numerical methods. The effects of vertical load, pile–tunnel distance, and tunnel-cover depth on the horizontal displacement and the bending moment of adjacent piles were investigated. The results show that the shield tunnel induced adjacent pile displacement toward the tunnel side near the tunnel axis, and the soil below and above the tunnel axis constrained the pile, displacing toward the tunnel side. The maximum values of the horizontal displacement and bending moment were at the tunnel axis. The vertical load on the cap had little influence on the horizontal response of the pile. The main influence area induced by shield construction was located within 1.5 times the tunnel diameter. The maximum horizontal displacement and maximum bending moment were reduced by 36–45% and 45–78% on the far pile due to the shading effect induced by the near pile. The tunnel-cover depth had a significant influence on the distribution patterns of the horizontal displacement and the bending moment. The positions of the maximum horizontal displacement and the maximum bending moment moved downward with increases in tunnel-cover depth. The maximum horizontal displacement and bending moment increased with increases in tunnel-cover depth.
... When the new tunnel structure intersects with existing structures, there will be interactions between these structures. Several studies have been conducted to investigate the interactions between new tunnels and existing underground structures (Basile, 2014;Cheng et al., 2007;Hong et al., 2015;Lee and Ng, 2005;Liu et al., 2014;Wang et al., 2018). From these studies, it is evident that when a new tunnel is constructed in close proximity of existing structures, the J o u r n a l P r e -p r o o f existing structures are subjected to additional deformation. ...
Increasing demand for subways or metros has resulted in the need to build new tunnels in close proximity of pile foundations of existing underground structures. This study presents the details of cutting of existing large diameters reinforced concrete group piles which lie in the excavation path of the new tunnel directly by shield. Investigation is made based on the on-site case study of the construction of the right tunnel of Shenyang Metro Line 4, which crosses the Shenyang North Station of Metro Line 2. During the process, 17 reinforced concrete piles with diameters ranging from 800 to 1000 mm were cut. The details of the ground improvement, the replacement of the cutter, the cutting of the reinforced concrete piles, and the wear of the cutter are presented in this paper. From the monitoring data, it is found that the advancing speed is lower during the cutting of reinforced concrete piles, and the values of thrust and torque fluctuate. The field measurements show that the settlements and horizontal displacements in the existing tunnel and metro station are within the allowable limits when the reinforced concrete piles are cut directly with the shield. During the cutting of the reinforced concrete piles, the steel rebars usually break under tensile stress, and the tension fracture accounts for 66.2 % of the total fracture of steel rebars. The cutters installed at different heights have a cumulative effect on the cutting of piles, and the cutters installed at higher positions have a protective effect on the cutters installed at lower heights. The average wear amount of rippers at 165, 175, and 210 heights are 6 mm, 15.2 mm, and 24.8 mm respectively. The construction method used in this project can serve as a reference and experience for similar future projects.
... To investigate the effect of seepage on soil arching effect in deep shield tunnel, a case history named the Shanghai West Changjiang Road Tunnel Project (Liu et al., 2014) is chosen to create a 3D finite element model (FEM) whose calculated data are compared with field data to verify the rationality of the deep shield tunnel model (see Section 2.3) and related parameters. The project crosses the Huangpu River, which starts from the west bank and ends on the east bank, and the total length is 4.9 km. ...
... 60 excavation steps (i.e., the excavation length is 124 m) and 60 consolidation steps are simulated in staged tunneling. According to Liu et al. (2014), the tunneling speed is 7 rings/day (i.e., 1 ring/0.14 days). ...
... The detailed simulation process of the tunneling is similar to Lin et al. (2019), which is not stated here. Based on the FEM established by Liu et al. (2014) and the numerical verification to be completed (see Section 2.2.4), the related tunneling parameters are stated here. The support pressure increasing with depth is 310 kPa at the crown of the tunnel face, with an increment of 12.34 kPa along the vertical direction. ...
