工字钢冷弯机价格行情走势

公路;开工建设会宁至通渭、清泉至七墩等15个普通国道;开工建设山丹至马场二场等普通省道。

青海

2016年拟开工8个公路项目(均已完成招标)，分别是：达日经石渠至玉树公路(青海境)工程(全长约448公里)、215国道马鬃山口岸至宁洱公路涩北至察尔汗段公路工程(全长约163公里)、306省道官亭至哈城公路(全长约313公里)、312省道玛多至色吾沟公路(全长约337公里)、G0611张掖至汶川高速扁都口(甘青界)至门源(克图)段(全长约150公里)、213国道祁连县城叉路口至大通河桥段公路改建工程(全长约76公里)、345国道杂多至查吾拉段公路改建工程(全长约211.7公里)、224省道二道沟兵站109岔口至治多段公路改建工程(全长约430.6公里)。

内蒙古

高速公路：抓好京新高速临河至蒙甘界段、丹锡高速大板至经棚至锡林浩特段、绥满高速海拉尔至满洲里段、S31大饭铺至龙口高速、临河至白疙瘩高速、苏尼特右旗至化德高速等项目建设。

      干线公路：推进尼尔基至大杨树、阿力得尔至阿尔山、满洲里至阿拉坦额莫勒、海拉尔至哈达图至拉布大林、锡林浩特至别力古台至满都拉图等一级公路建设;年内新增新巴尔虎右旗、阿拉善右旗两个旗通一级公路。

广西

高速公路：新开工荔浦至玉林、贺州至巴马(昭平至蒙山段)、南宁至钦州至防城港改扩建等6个项目;续建贵港至合浦、梧州至柳州等高速公路项目;争取建成通车岑溪至水汶、崇左至靖西、南宁吴圩机场二高速、桂林绕城高速路面改造等7个项目;新增大新、天等两个县通高速公路。

      国省干线和一般路网：加快来宾迁江至马山古零、凤山至凌云等项目进度;争取开工瑶山至南丹、马坡至陆川、苍梧梨埠至马江等项目。

西藏

高等级公路：启动G6格尔木至拉萨高速公路，日喀则市至吉隆、狮泉河至普兰、G4217线德格至昌都、G4218线和G0613线林芝至邦达机场高等级公路前期工作。一季度开工建设318国道林芝至拉萨(二期)工程、318国道和109国道拉萨市过境段、349国道贡嘎机场至泽当段、318国道日喀则至日喀则机场段;二季度开工建设S6线昌都至加卡段、浪拉山至邦达机场段、G6格尔木至拉萨高速拉萨至那曲段;三季度开工建设S5线拉萨至泽当快速路、沿边横向大通道(中段)、219国道萨嘎县至朗县金东乡公路改建工程。

      国省干线：推进318国道竹巴笼至林芝段整治改造、青藏界至昌都(柴维)段、泽当至米林段等前期工作;开工建设349国道边坝经嘉黎至墨竹工卡到乃东、216国道民丰至改则、303省道嘉黎县忠玉乡至波密县八盖乡等公路改建工程。

新疆

隧道支护结构体系是围岩稳定性控制的关键,也是隧道设计的基本任务,而对支护结构之间相互作用过程和机制的系统认识则是定量化设计的基础. 本文从隧道围岩结构性和支护作用的本质特征出发,提出隧道支护具有"调动"和"协助"围岩承载的基本作用,明确了二者的功能分配原则和实现方式,即分别通过超前支护的保障作用、初期支护的核心作用和二次衬砌的储备作用共同完成;针对围岩的正面挤出、前倾式冒落和后倾式冒落等三种超前破坏模式,分别给出了相应的超前支护方式和支护效果评价方法;提出初期支护作为隧道围岩附加载荷的主要承担者,包括锚固体系与拱架及喷射混凝土结构,分别通过"调动"和"协助"围岩实现其承载功能,且同时具有"支"与"护"的作用;阐明了二次衬砌结构作为储备功能的内涵,建立了二次衬砌结构的载荷分担比率与刚度匹配性、支护时机的关系,并据此给出了二次衬砌结构参数和施作时机的建议值;建立了以围岩变形量$S$小和协同度$\xi$优为目标,基于超前支护、初期支护和二次衬砌与围岩相互作用三阶段的协同支护优化模型,明确了支护结构体系与围岩、不同支护结构之间以及支护结构要素之间三个层次的协同关系,并提出了隧道支护结构体系协同优化设计方法.

关键词: 隧道工程, 支护结构体系, "支护——围岩"动态作用, 协同作用, 支护结构设计

Abstract:

Tunnel support structure system is the key of controlling the stability of surrounding rock, which is also the basic task of tunnel design, while systemic understanding of the process and mechanism of interaction among support structures is the basis of quantitative design. This paper embarks from structural property of tunnel surrounding rock and the constitutive property of support effect, the basic function of tunnel support that "mobilizing" and "assisting" surrounding rock bearing is put forward, of which the function distribution principle and realization way are clarified, namely, through the guarantee role of advanced support, the core role of primary support and safety reserve role of secondary lining to complete. In view of three advanced failure modes including the positive extrusion, the forward type caving and posterior tilt falling of surrounding rock, the corresponding advanced support pattern and its effect evaluation method are given respectively. The primary support is the main undertaker of tunnel surrounding rock additional load, including the anchorage system and the arch and shotcrete structure, whose bearing function is carried out by "mobilizing" and "assisting" surrounding rock respectively, and also have the function of "bracing" and "protecting". The connotation of secondary lining structure as security reserve function is illuminated. The relationship between load sharing ratio and stiffness matching and support time of secondary lining structure is established, according to which the suggestive values of structure parameters and support time of secondary lining are provided. The collaborative support optimization model is set up based on the three stages of the interaction between advanced support, primary support, secondary lining and surrounding rock, whose targets are minimizing surrounding rock deformation S and optimizing synergy degreeξ. Three levels of synergy including relations between support structure system and surrounding rock, different support structures and different support structure elements are clarified. And a collaborative optimization design method for tunnel support structure is proposed.