Adjacent High-rise Buildings Research Articles

Assessment of the influences of post-construction facilities on pedestrian-level wind environment: An experimental study in Changsha, China

With continuous urbanisation, an increasing number of post-construction facilities (such as high-rise buildings and green plants) have altered the original layout of the community. Which has resulted in deterioration of the wind environment. However, there is a deficiency of qualitative studies on the pedestrian-height wind environment that focus on the influence of post-construction facilities. The presents research takes Changsha universal time community as a case study. A wind tunnel test at a scale of 1:250 was performed to analyse the wind environment by considering the post-construction facilities. 81 sets of cases with different inflow patterns, wind directions, adjacent high-rise buildings, and plants were examined to reveal the flow field distribution characteristics. Furthermore, the exceedance probability method was introduced to assess the wind environment of the community in different cases. The results indicate that the index distribution coefficient of wind velocity and the turbulence intensity profile inside the practical community is significantly larger than the code values. A roughness distance of 800 m can generate highly effective mean wind profiles. However, it is unable to generate the desired turbulence profiles. Considering the post-construction facilities, high-rise buildings cause acceleration effects on the average wind velocity and the acceleration effects are inversely proportional to the distance of the post-construction facilities. Large, medium, and small trees cause deceleration effects of the average wind speed and improve the wind environment comfort quality of the community.

The combined effect of seismic-induced collision and soil stress irregularity on seismic response of adjacent high-rise buildings: Evaluation and mitigation

The combined effect of seismic-induced collision and soil stress irregularity on seismic response of adjacent high-rise buildings: Evaluation and mitigation

Influence analysis of blasting on adjacent high-rise buildings for deep rock excavations in urban area: a case study

Influence analysis of blasting on adjacent high-rise buildings for deep rock excavations in urban area: a case study

Interference Effects of Adjacent High-Rise Building on Wind-Induced Response of Low-Rise Flat Roof Building

Interference influence of the spacing and height ratio on the modal generalized force and wind-induced response of the low-rise building roof due to one adjacent high-rise building is investigated at three typical wind directions of 0∘, 90∘ and 180∘, where the low-rise building was, respectively, located at the upstream, side-by-side and downstream of the high-rise building. The mean and standard deviation of the modal generalized force of the first vibration mode mainly exhibits reduction effects and amplification effects, respectively, at the wind direction of 0∘ and 90∘ at small building spacing, and first experiences shielding effects and then becomes amplification effects when the height ratio increases at the wind direction of 180∘. The maximum displacement mainly presents reduction effects at the wind direction of 0∘, the interference factor decreases with the increase of the reduced frequency in engineering range, and the minimum interference factor is close to 0.2. At the wind direction of 90∘, the maximum displacement mainly presents amplification effects, these effects are obvious when the spacing ratio is small and the height ratio is large, and the maximum interference factor is close to 2.2 when the reduced frequency is larger than 0.3. At the wind direction of 180∘, the maximum displacement shows significant amplification effects when the building spacing is small and the height ratio is large, the amplification effects gradually weaken and change into shielding effects as the building spacing increases or the height ratio decreases, and the minimum interference factor is close to 0.3. The minimum displacement experiences amplification effects at all three typical wind directions.

Comparison of Dynamic Responses of Parallel-Placed Adjacent High-Rise Buildings under Wind and Earthquake Excitations

Two parallel-placed adjacent high-rise buildings are often linked to each other through passive control devices for vibration mitigation purposes. The mitigation efficiency of these control devices mainly depends on the characteristics of relative dynamic responses, namely, opposite-sign and same-sign responses of the two buildings. The present research first identifies an opposite-sign response factor to estimate the time ratio of opposite-sign responses. Subsequently, a structure comprising two adjacent high-rise buildings (with different natural frequency ratios) subjected to both wind and earthquake excitations is analyzed. Wind-induced responses are evaluated based on wind loads obtained from wind tunnel tests, while earthquake responses are determined through a suite of 44 natural ground-motion records. The results indicate that opposite-sign factors of the displacement, velocity, and acceleration responses under wind loads, especially at across-wind direction, are larger than those under earthquake excitations, and opposite-sign response factors under wind loads are insensitive to variation of the natural frequency ratio of the two adjacent buildings compared with those under earthquake excitations. The conclusions of this research may be helpful for wind-resistant and antiseismic design of parallel-placed adjacent high-rise buildings.

Nonlinear study on the structure-soil-structure interaction of seismic response among high-rise buildings

Based on the 1–3 identical high-rise buildings with pile-raft foundation, a series of building-site two-dimensional finite element analysis models with different building spacings is established. Then, considering the nonlinear characteristics of soil and structure, the static-dynamic coupled numerical simulations are conducted to study the structure-soil-structure interaction (SSSI) under different ground motion. The results show that: 1) Adjacent high-rise buildings have the most unfavorable impact on the peak acceleration of the 1/4–1/2 height floors of the middle building, and increase the normalized response acceleration spectra value of acceleration near the second natural period of the structure; 2) Adjacent high-rise buildings have the most significant impact on the inter-story drift of the top, bottom and basement of the middle building; 3) Adjacent high-rise buildings redistribute the total horizontal shear force of the pile top of the middle building among the pile foundations, so that the peak value of the pile top shear force of each pile changes significantly, which is extremely unfavorable to the seismic safety of the structure. It should be taken seriously in the seismic design of structures. In addition, the structure spacing that results in favorable or unfavorable effects is discussed, and the reasons for the impact are analyzed.

Seismic performance of optimal Multi-Tuned Liquid Column Damper-Inerter (MTLCDI) applied to adjacent high-rise buildings

Conventional vibration absorbers, e.g., a classical tuned mass damper, may be not efficient in simultaneously controlling the seismic response of adjacent high-rise buildings. In this paper, a novel passive vibration control system, denoted as Multi-Tuned Liquid Column Damper-Inerter (MTLCDI), is developed to control the seismic response of adjacent high-rise buildings. Two different configurations of this system, namely inter-story MTLCDI (IS-MTLCDI) and inter-building MTLCDI (IB-MTLCDI), are proposed, and related mathematical models are developed to investigate the seismic performance of MTLCDI. A case study project comprising two adjacent high-rise buildings equipped with the proposed system and subjected to ten earthquake records with various frequency characteristics is considered. Performance-based parametric optimization of the MTLCDI systems is performed through two distinct constrained multi-objective optimization problems via genetic algorithms, wherein peak absolute accelerations and inter-story drift ratios of the two adjacent buildings are selected as performance indexes. The mitigation effects of optimum IS-MTLCDI and IB-MTLCDI on earthquake-induced vibrations are scrutinized, with emphasis placed on the effects of natural frequency ratios between the two host structures. The results indicate that, when the two buildings have distinct natural frequencies, both IS-MTLCDI and IB-MTLCDI outperform inter-building single TLCDI as well as other vibration absorbers in terms of seismic vibration control of absolute acceleration and inter-story drift ratios. Under most natural frequency ratios, the IS-MTLCDI achieves a larger response reduction than IB-MTLCDI. Nevertheless, when the differences between natural frequencies of adjacent buildings are significant, applying an IB-MTLCDI may be preferable due to its satisfactory mitigation effects combined with ease of installation.

LiDAR-derived three-dimensional ecological connectivity mapping for urban bird species

Although many studies have considered urban structure when investigating urban ecological networks, few have considered the three-dimensional (3D) structure of buildings as well as urban green spaces. Airborne LiDAR datasets provide an opportunity to quantify 3D structure and evaluate 3D metrics in connectivity mapping. We examined an urban ecological network using the 3D structure of both green spaces and buildings. Using breeding-season bird species observations and airborne LiDAR data collected, we assessed the influence of 3D structural variables on species diversity. We used correlation analyses to determine if vertical distribution, volume, area, and height of both buildings and vegetation were related to bird species diversity. Then we conducted circuit theory-based current flow betweenness centrality (CFBC) analysis using the LiDAR-derived structural variables. We found that the volumes of buildings and 8–10 m vegetation heights were both highly correlated with species richness per unit area. There were significant differences between 2D and 3D connectivity analysis using LiDAR-derived variables among urban forest patches, boulevards, and apartment complexes. Within urban forest patches and parks, 3D CFBC represented canopy structural characteristics well, by showing high variance in spatial distributions. The 3D CFBC results indicated that adjacent high-rise buildings, dense apartment complexes, and densely urbanized areas were isolated, as characterized by low centrality values, but that vegetation planted in open spaces between buildings could improve connectivity by linking isolated areas to core areas. Our research highlights the importance of considering 3D structure in planning and managing urban ecological connectivity.

Wind-induced vibration control and parametric optimization of connected high-rise buildings with tuned liquid-column-damper–inerter

A novel passive control device, defined as tuned liquid-column-damper–inerter (TLCDI), with nonlinear characteristics is developed for control of the wind-induced responses of adjacent high-rise buildings. TLCDI exploits the combined advantages of liquid sloshing inside TLCD container as well as mass amplification effects of the inerter to control the wind induced responses. Firstly, a model for adjacent high-rise buildings linked by a TLCDI is established subjected to wind loading. Subsequently, an equivalent linearization method is used to study the model, and the results are verified by a numerical method. Finally, mitigation effects of the TLCDI with optimal designs on wind-induced responses are investigated by comparison studies with the results of two tuned liquid column dampers (TLCDs) installed on benchmark buildings. The results indicate that the TLCDI, which is much lighter than two TLCDs, dramatically decreases the wind-induced acceleration responses of the linked buildings by 37.7% (Building-1) and 42.0% (Building-2) at the across-wind direction (90° wind direction).

Influence of Blasting Vibration of MLEMC Shaft Foundation Pit on Adjacent High-Rise Frame Structure: A Case Study

The construction of metro line energy management center (MLEMC) is one of the important parts of metro line, which is the key organization to realize the energy consumption management of the metro operation. To protect the safety of adjacent high-rise buildings during the blasting of subway foundation pit engineering, it is crucial to study the response characteristics of building structures. This paper takes the MLEMC vertical pit blasting project of Wuhan Metro Line 8 as an example. The law of blasting vibration attenuation along the earth’s surface and the vibration velocity response characteristics of the building structure were analyzed by small explosive test. LSDYNA numerical model was established, and the reliability of the model and parameters was verified by experimental data. Combined with the relevant specifications, the maximum charge in single delay was calculated and analyzed. The numerical model of the maximum charge in single was established, and the prediction model of the vibration velocity related to the floors of high-rise buildings was further proposed. Combined with the failure principle of reinforced concrete structure, the safety of high-rise buildings under blasting vibration was analyzed and evaluated.

Seismic response control of adjacent high-rise buildings linked by the Tuned Liquid Column Damper-Inerter (TLCDI)

A novel passive control device termed Tuned Liquid Column Damper-Inerter (TLCDI) is adopted to control the seismic response of adjacent high-rise buildings. The inerter of the proposed TLCDI scheme exploits the large relative acceleration between the two adjacent buildings, producing a significant resisting force. Firstly, the governing nonlinear equations of motion of the TLCDI-linked adjacent high-rise buildings under earthquake excitation are formulated. For design purposes, the inherent nonlinear behavior of the TLCDI is linearized by adopting an equivalent stochastic linearization method. Subsequently, a benchmark structure consisting of two adjacent high-rise buildings linked by a corridor with a roller support and equipped with a TLCDI is examined. Eight characteristic parameters of the TLCDI are optimized through two distinct constrained multi-objective optimization problems by an evolutionary algorithm aimed at minimizing either the peak acceleration or the interstory-drift ratio of the two adjacent benchmark structures, respectively. Mitigation effects of the optimally designed TLCDIs on the responses of the benchmark structure are assessed considering a set of ten natural ground-motion records. It is found that the optimum TLCDI achieves mean reduction ratios of 15.7 and 26.1% on the peak acceleration of both the buildings, respectively. Conversely, the TLCDI fails to significantly reduce the interstory drift ratios. Robustness analysis of the optimally designed TLCDI is investigated under perturbations to the frequency and damping ratios. Some practical considerations are finally discussed concerning the feasibility of employing the proposed TLCDI in the considered benchmark project.

Urban Design with the Wind: Pedestrian-Level Wind Field in the Street Canyons Downstream of Parallel High-Rise Buildings

We are investigating how to use urban design approaches to conduct the layout and basic design of newly-built high-rise buildings to reduce wind obstruction and create effective urban ventilation. Few studies have addressed this issue. This study analyzes the effects of high-rise building on pedestrian-level wind in downstream street canyons based on wind tunnel test results, and examines the suitability of an urban design specification. The height (H) of high-rise buildings and the airflow passage width (S) between adjacent high-rise buildings are key control factors for this issue; H/D = 3 and S/D = 1.125 are critical parameters and recommended values (D is the height of the downstream street blocks).

Design, Construction and Uncertainties of a Deep Excavation Adjacent to the High-Rise Building

In present infrastructure development, deeper basements are provided to satisfy parking scarcity. Safety and economy decide the system of shoring to go deeper below the ground level. This paper provides the design and construction of a deep excavation for an office building located at Bengaluru. Finite element model developed through PLAXIS 2D software is used for designing the shoring system in the present case study. The design and construction of two different deep excavation schemes are discussed in this paper, they are proposed based on the soil profile, constraint of space, presence of adjacent structures and service lines. Along the excavation line at some locations, existing buildings were located in very close proximity leading to lack of space for providing required slope for stabilising with driven nails, so in order to keep the excavation sides stable in those locations contiguous pile with soil/rock anchors was proposed. This deep excavation was of particular interest because of the uncertainties faced during construction which lead to failure of almost 20 m deep slope adjacent to existing high-rise building. The existing adjacent high-rise building was fully functional at the time of deep excavation. Potential large deformation of the adjacent high-rise building caused due to slope failure was one of the main concerns immediately after the failure. The immediate remedial measures taken to safeguard the footing of the existing high-rise building has also been included in this paper. The measure includes like immediate backfilling followed by grouted nail proposed along the failure surface.

Wind Characteristics Investigation on The Roofs of Three Adjacent High-Rise Buildings in a Coastal Area during Typhoon Meranti

This paper presents the study of the pulsating characteristics of three adjacent high-rise buildings A, B, and C under typhoon ‘Moranti’ (2016) based on the measurement of the actual top wind speed. The studied pulsating characteristics included mean wind speed and direction, turbulence intensity, gust factor, turbulence integral scale, wind speed spectrum and correlation. The relationships between each pulsating parameter and the relationship between the pulsating parameter and gust duration have been investigated. Results show that the mean wind speed and wind direction of three buildings are close. When U ≥ 10 m/s in three different sites at the same time, the turbulence intensity variation of three buildings is consistent and decreases when mean wind speed increases. Once only two locations are acquired simultaneously and the wind angle between 35° and 45°, the mean values of the along-wind and cross-wind turbulence of building A and building C are close. The along-wind turbulence of the three buildings is greater than the predicted Chinese codes for various terrains. The turbulence intensity and gust factors obtained through the analysis of the samples with the mean wind speed U ≥ 10 m/s are reasonable. The turbulence integral scales of buildings A and C are equal to the predicted values of ASCE-7 and AIJ-2004, whereas the turbulent integral scale of building B is evidently small. The gust factors of three buildings increase when the turbulence intensity increases; these two characteristics have a linear relationship. At the same time interval, building B has the maximum along-wind turbulence intensity and gust factors during the low wind speed period and building C achieves the minimum values. Building A acquires the maximum and building C obtains the minimum values in the high wind speed period. The turbulence intensity and gust factors of building B show a certain pulsation. Results show that turbulence intensity and gust factors are mainly affected by the short-term fluctuation of wind. The longitudinal wind speed spectrum of three buildings conforms well to the von Karman model. The correlation of along-wind speed depends on the wind speed, whereas the correlation of cross-wind direction is independent of wind speeds. The measured data and statistical parameters provide useful information for the wind resistance design of high-rise buildings in typhoon-prone areas.

About the Artist: Kalisolaite 'Uhila

About the Artist:Kalisolaite 'Uhila Moana Nepia Click for larger view View full resolution Photo by Patti Solomona Tyrell While on a 2018 residency at the Youkobo Art Space in Tokyo, Tongan-New Zealand performance artist Kalisolaite 'Uhila connected with other Tongans living there, undertaking research into their experiences of Asian culture and the nature of time—how its use and contours may change according to where we might be located, the spaces we inhabit, and the people with whom we are sharing those spaces. Researching the inter action between bodies and ideas in and through time informs both philosophical and material aspects of his work as a performance artist. Audiences responding to the sensory and visual impact of his work are drawn to contemplate its metaphorical references to Pacific Islander experiences in historical and geopolitical contexts. Similarly, a personal focus on relationships with others, and life outside the time and space of performance, provides 'Uhila with a meditative still-point that enables him to endure the emotional and physical demands of site-specific, durational practices. After living in a shipping container with a pig for a week, inhabiting the streets of Auckland for three months for a project about homelessness, performing on theroof of a gallery to bemused spectators in adjacent high-rise buildings and the street below, and since "cooking" himself in an umu, 'Uhila has attracted a loyal following, received numerous awards, and been in demand for regional and international exhibitions and residencies in New Zealand, Germany, Canada, Japan, Tonga, and the Cook Islands. In 2016, he completed his master's of performance and media arts at Auckland University of Technology (aut) with first-class honors. He is represented by Michael Lett in New Zealand (http://michaellett.com) and in 2019 is a featured artist in the second Honolulu Biennial (https://www.honolulubiennial.org). The art featured in this issue can be viewed in full color in the online versions. [End Page v] Click for larger view View full resolution Mo'ui tukuhausia, by Kalisolaite 'Uhila, 2012 and 2014. Performance, Te Tuhi Centre for the Arts, 2012; The Walters Prize, Auckland Art Gallery, 2014. Photo by Bruce Phillips, courtesy of the artist and Michael Lett. In an effort to draw attention to increasing levels of homelessness in Auckland, one of the most expensive cities in the world, 'Uhila took up a week-long residency in the grounds of Te Tuhi Centre for the Arts in 2012 and on the city's streets for three months in 2014. Mo'ui tukuhausia, meaning "to be absolutely stranded," "left friendless," or "destitute," also draws attention to theemotional experiences and disproportionate overrepresen tation of Pacific Islandersfacing homelessness in other Pacific centers, such as Honolulu, Saipan, Papeete, Suva, Port Moresby, or Sydney. [End Page vi] Click for larger view View full resolution Mo'ui tukuhausia, by Kalisolaite 'Uhila, 2012. From the exhibition What do you mean, we?, Te Tuhi Centre for the Arts, 3 March–6 May 2012. Photo by Bruce Phillips, courtesy of the artist and Michael Lett. 'Uhila's message on this cardboard placard for Mo'ui tukuhausia is a call to action that recognizes the transformative political power of the personal gesture. It also prompts us to think beyond small, random acts of charity and toward sustainable solutions for homelessness that will bring lasting change. Attacking issues of climate change and sea-level rising, poverty, pollution, human rights abuses, and the scourge of lifestyle-related diseases in the Pacific requires similar emphasis on raising personal and collective levels of consciousness, shifting focus away from the self-centered excesses of neoliberalism and isolationist thinking, reaffirming universal rights, and values of kindness and respect, multilateral thinking, and collaboration. [End Page vii] Click for larger view View full resolution Umu Tangata, by Kalisolaite 'Uhila, 2013. Performance, volcanic rocks, wood, smoke machine, lights. Mangere Arts Centre, Auckland. Photo courtesy of the artist and Michael Lett. While preparing for Umu Tangata, 'Uhila was thinking about his role as an artist—sacrificing himself as "an offering" for his people, his country, and his work. In order to sustain the physical ordeal of this eight-hour performance, he described "energizing himself" outside...

Experimental verification of a dynamic model for lane-less (Indian) traffic

In a recent paper (Chavan et al. (2016)), the authors proposed a dynamic model of traffic behaviour on (Indian) roads, where lane discipline is not maintained even when the roads are wide and multiple vehicles can travel abreast. The primary hypothesis in this model was that each driver is influenced by an assortment of neighbouring cars and not only by the vehicle immediately in front. The proposed equations claim to be a model for driver/vehicle movement on such roads and hence should be able to predict actual motion of real vehicles. In this paper we experimentally verify this claim, after suitable modification of the theory to make it applicable for heterogeneous traffic. Videos of normal traffic on a sample road in Mumbai city, India, is recorded from the top of an adjacent high-rise building. Detailed motion information of groups of cars is extracted through novel image processing techniques. The proposed model is initialized with the extracted data and the computed trajectories are compared with the actual ones calculated from the images. It is verified that the proposed model can accurately predict complex maneuvers, such as overtaking, sideways movements (lane-changing) and avoiding collisions with slower moving vehicles.

Analysis of interference effects on torsional moment between two high-rise buildings based on pressure and flow field measurement

Wind induced interference effects between high-rise buildings have become quite important in structural engineering in modern cities recently due to the close proximity of high-rise buildings. In this study, the wind induced interference effects on the torsional load on two adjacent high-rise buildings are studied through wind tunnel experiment. Two different sectional shapes of high-rise buildings are studied and four kinds of arrangements are investigated. Existing interference factors are adopted to quantitatively evaluate the interference effects. Results show that the mean torsion on a building when under interfered conditions can be tripled that for the isolated case. Although the interference effect on the fluctuating torsion is not as strong as on the mean torsion, the interference factor can be as large as 1.6. The extreme torsion under interference effects is also higher at 1.8 times that of the isolated case. With the help of pressure measurement on the principal building and the flow field information around the buildings, the underlying mechanisms of some typical cases which exhibit strong interference effects are discussed. Results show that the intricate flow field around the principal building with the presence of an interfering building is the main case of the large torsion it experiences.

Numerical Simulation of Wind Field Characteristics around Two Adjacent High-Rise Buildings

This paper based on Reynolds-averaged Navier-Stokes equations standard model [1]; the surface pressure on the wind field around two adjacent high-rise buildings was numerically simulated with software Fluent. The results show that with the influence of adjacent high-rise building, numerical simulation is a good way to study the wind field around high-rise building and the distribution of wind pressure on building’ surface. The pressures on the windward surface are positive with the maximum at 2/3 H height and have lower values on the top and bottom. The pressures on the leeward surface and two sides were negative. Due to the serious flow separation at the corner of building’s windward, the wind field has a high turbulent kinetic energy.

Effect of cantilever soldier pile foundation excavation closing to an existing composite foundation

Adjacent high-rise building with CFG pile composite foundation was studied using model test method to investigate stress and displacement of the foundation pile retaining structure, the subsidence and transmogrification law of the composite foundation. Two different project cases with and without high-rise building adjacent to pile foundation were compared. The relationships of slope pile bending moment, earth pressure, pile top displacement and complex settlement with respect to time were obtained. 1) When there is no adjacent building, the displacement of supporting system caused by excavation is mainly in the horizontal direction; while when the adjacent building exists, the displacement of supporting system will be vertical. 2) When the excavation depth is less than or equal to the adjacent building’s composite foundation depth, the force of supporting structure is uniform and has small value, at the same time, the pile strength is in fully use and the foundation is stable; while when the excavation depth is greater than the depth of adjacent building’s composite foundation, the results will be opposite. 3) During the excavation process, the adjustment of the composite ground loads on the supporting structure is carried out downward and the force of the supporting structure is reduced through the deformation of the bearing layer.

Bearing capacity of single pile and in-flight T-bar penetration for centrifuge modeling of land subsidence caused by the interaction of high-rise buildings

With an increasing number of high-rise buildings in major cities worldwide, land subsidence induced by the interaction between closely-spaced buildings in soft soil areas has become a major challenge for many researchers. The paper considers the interaction of high-rise buildings by determining the bearing capacity of a single pile in the centrifuge model test. The T-bar penetration test was conducted in flight to measure the shear strength of the soft soil, together with vane shear tests when the model had slowed down. By analyzing the relationship curves between land subsidence and the centrifuge acceleration, the allowable bearing capacity of a single pile for the high-rise building was obtained. It is considered that such analysis is a more appropriate method of determining the pile requirements for groups of adjacent high-rise buildings in soft soil areas.